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A serial of hexagonal-prismatic metal organic cages (MOCs), [Co 6 (OH) 2 (HCOO) 6 (pbim) 6 (H 2 O) 6 ]·SO 4 ·2HCOO·8H 2 O (1 ·2HCOO·8H 2 O), [Ni 6 (OH) 2 (HCOO) 6 (pbim) 6 (H 2 O) 6 ]·SO 4 ·2HCOO·8H 2 O (2 ·HCOO·8H 2 O), {[Co 6 (μ 3 -OH) 2 (μ- HCOO) 6 (pbim) 6 (H 2 O) 6 ]·ClO 4 }3+·3HCOO·solvent (3 ·3HCOO·solvent) and {[Ni 6 (μ 3 -OH) 2 (μ- HCOO) 6 (pbim) 6 (H 2 O) 6 ]·ClO 4 }3+·3HCOO·solvent (4 ·3HCOO·solvent), was constructed from shuttlecock-like C 3 -symmetric [M 3 (μ 3 -OH) (μ -HCOO) 3 (H 2 O) 3 ] (M = Co2+ or Ni2+) clusters generated in situ and a clip-like ligand 1,1'-(5-methyl-1,3-phenylene)bis(1H-imidazole) [pbim]. Interestingly, one SO 4 2− or ClO 4 − anion was encapsulated in each cage of MOCs 1 – 4 through cooperative O–H⋯O and C–H⋯O hydrogen-bonding interactions. It was also found that those SO 4 2‒-/ClO 4 −-encapsulated MOCs, especially SO 4 2‒-encapsulated MOC of Ni2+, displayed quite stability in methanol. Notably, when the crystal parent solution of MOC 1 was disturbed or MOC 1 was immersed in its parent solution for a long time, it resulted in the formation of a 2D coordination polymer [Co(pbim) 2 (H 2 O) 2 ]·2HCOO (5) with helical architecture. Unexpectedly, a novel 2D coordination polymer [Ni 4 (pbim) 2 (CH 3 O) 4 (C 6 H 5 COO) 4 ]·2H 2 O (6 ·2H 2 O) based on in-situ produced cubane-like [Ni 4 (μ 3 -CH 3 O) 4 (μ- COO) 2 ] cluster was solvothermally synthesized through the reaction of benzoic acid with relatively stable MOC 2 in DMF. Magnetic studies show that there are antiferromagnetic coupling exchanged by mixed hydroxyl/carboxylate bridges in shuttlecock-like [M 3 (μ 3 -OH) (μ -HCOO) 3 (H 2 O) 3 ] clusters of 1 and 2 or in cubane-like [Ni 4 (μ 3 -CH 3 O) 4 (μ- COO) 2 ] cluster of 6. The best fits for their magnetic behaviours gave the following coupling constants: J = −2.05 cm−1 for 1 , J = −1.74 cm−1 for 2 , and J 1 = −2.85 cm−1 and J 2 = −4.01 cm−1 for 6. Four novel hexagonal-prismatic metal‒organic cages constructed from shuttlecock-like C 3 -symmetric [M 3 (μ 3 -OH) (μ -HCOO) 3 ] clusters generated in situ and a clip-like ligand were characterized in solid and solution. Interestingly, the encapsulated SO 4 2− or ClO 4 − anions play an important role in the directional construction of these metal‒organic cages through forming multiple O–H⋯O and C–H⋯O hydrogen bonds with them. [Display omitted] • Hexagonal-prismatic metal‒organic cages constructed from C 3 -symmetric metal-cluster units. • Novel coordination polymer based on cubane-like [Ni 4 (μ 3 -CH 3 O) 4 (μ- COO) 2 ] cluster. • Magnetic investigation. [ABSTRACT FROM AUTHOR]

The Ir 8 Al 21.22 binary intermetallic compound was synthesized using arc melting technique. Its crystal structure probed by single-crystal X-ray diffraction is a superstructure variant of the previously reported cubic IrAl 2.75 compound. Ir 8 Al 21.22 crystallizes in the Fmm 2 space group with the unit cell parameters of a = 15.3307(9) Å, b = 15.3226(10) Å, c = 15.3129(9) Å, and V = 3597.1(4) Å3. The crystal structure contains columns of interpenetrating distorted icosahedral clusters – a characteristic feature of the approximant phases and quasicrystals. Electronic structure calculations indicate strong hybridization between valence orbitals of iridium and aluminum atoms accompanied by the formation of pseudogap, which separates the valence and conduction bands. [Display omitted] • The crystal structure of binary IrAl 2.75 has been re-examined as Ir 8 Al 21.22 • The crystal structure of Ir 8 Al 21.22 is not cubic, but orthorhombic. • The orthorhombic cell dimensions a, b, and c of Ir 8 Al 21.22 are very close. • The crystal structure of Ir 8 Al 21.22 is quite complex at large unit cell ∼3600 Å3. • The Fermi level is located in the vicinity of deep pseudogap. [ABSTRACT FROM AUTHOR]

Li 2 TiO 3 :Mn4+ has been previously identified as a potential candidate to replace commercial red-emitting Eu2+-activated phosphors. Its luminescent efficiency is limited by the presence of defects and the sensitivity of Mn4+ to redox processes. A series of co-doped Li 2 TiO 3 : x Mg2+, 0.01 Mn4+ samples were prepared to gain insight on the effect of electron doping on the structure and photoluminescent properties, through characterization by powder X-ray diffraction, elemental analysis, and optical spectroscopy. As Mg2+ substitutes for Li+, the ordered arrangement of cations within the honeycomb layers in the parent structure (Li 2 SnO 3 -type, an ordered derivative of rocksalt) gradually transforms to a more disordered arrangement. The increased cation site disorder leads to less intense and broader emission peaks as well as lower quantum yields. Mg substitution into Li 2 TiO 3 :Mn4+ introduces more extensive stacking faults and cation disorder, leading to less intense photoluminescence. [Display omitted] • Li 2 TiO 3 : x Mg2+, 0.01 Mn4+ samples were prepared up to x = 0.3. • Increasing Mg substitution leads to more cation disorder and stacking faults. • The photoluminescence emission becomes broader and less intense. [ABSTRACT FROM AUTHOR]

Perovskite (PVK) halides represent versatile materials in both production and application. Given their continuous focus in research, this article aims to provide a comprehensive review of lead-free perovskites based on antimony, characterized by the formula Cs 3 Sb 2 X 9 , with X representing Cl−, I− or Br−. The objective is to present the latest research findings at the time of writing this document, categorized by applications and their corresponding outcomes. Although this compound is predominantly studied in the domain of photovoltaic devices, it is important to acknowledge its relevance in other applications. Therefore, this article also investigates its utilization in other areas such as photocatalysis and light-emitting diodes (LEDs). Key parameters such as crystalline structure and band gap (E g) are highlighted, given their significance in perovskite characterization. In essence, this work not only serves to disseminate knowledge about these materials but also aims to catalyze further research aimed at enhancing the utilization of lead-free perovskites across various domains. [Display omitted] • This is the first review on fully inorganic halogenated antimony-based perovskites. • The article provides a description of the works and justifies the observed chemical and physical phenomena. • Sb provides greater stability compared to lead-based inorganic perovskites and hybrid perovskites. • The article covers various works with different applications, focusing on photovoltaic devices and photocatalytic systems. [ABSTRACT FROM AUTHOR]

The rational design and construction of polyoxotitanium clusters with outstanding photoelectrochemical activity represents a significant challenge in the field. Herein, employing ferrocene as a photosensitizer and incorporating diverse auxiliary ligands, we have successfully constructed a family of structurally varied ferrocene-sensitized polyoxotitanium clusters, formulated as Ti 3 (μ 3 -O) (Fcc) 2 (O i Pr) 8 (Ti 3 Fcc- 1, Fcc = ferrocenecarboxylic acid), Ti 3 (μ 3 -O) (Fcc) (L1) (O i Pr) 8 (Ti 3 Fcc-2 , L1 = 6-amino- m -toluenesulfonic acid), Ti 6 (μ 3 -O) 2 (μ 2 -O) (Fcc) 2 (L2) 2 (O i Pr) 10 (Ti 6 Fcc-1 , L2 = salicylhydroxamic acid), Ti 6 (μ 3 -O) 4 (Fcc) 2 (L3) 2 (O i Pr) 10 (Ti 6 Fcc-2 , L3 = diisopropanolamine), and Ti 8 (μ 3 -O) 4 (Fcdc) 4 (L4) 2 (O i Pr) 10 (Ti 8 Fcdc , Fcdc = 1,1-ferrocenedicarboxylic acid, L4 = triisopropanolamine). The incorporation of auxiliary groups can effectively regulate the structure of ferrocene-functionalized polyoxotitanium clusters, resulting in a gradual growth of the cluster core from Ti 3 to Ti 6 , and ultimately reaching Ti 8. Moreover, these titanium-oxo clusters exhibit displayed enhanced visible light absorption and narrow bandgaps, which are primarily attributed to the charge transport from Fcc/Fcdc and ancillary groups to the cluster core. These Ti-oxo clusters were also used as electrode precursors for investigating their photoelectric behaviors and exhibited clear photocurrent responses. This work not only expands ferrocene-sensitized titanium-oxo clusters library, but also provides guidance for the rational design and controllable construction on titanium-based photoactive materials. Using organometallic complex ferrocene as photosensitizer and incorporating diverse auxiliary ligands, a family of ferrocene-sensitized Ti-oxo clusters with diverse structures and excellent optoelectronic properties were successfully synthesized. [Display omitted] • A family of ferrocene-sensitized titanium-oxo clusters were synthesized successfully. • Auxiliary ligand induction can trigger structural growth of titanium-oxo clusters. • Modification of ferrocene and auxiliary groups can broaden light absorption of these clusters. • These clusters as electrode precursors exhibited excellent photocurrent responses. [ABSTRACT FROM AUTHOR]

The complete solid solution Li x Ag 1– x AlSe 2 was prepared at 850 °C in the form of phase-pure powder samples as well as single crystals. They adopt noncentrosymmetric crystal structures belonging to the tetragonal CuFeS 2 -type (space group I 4 ‾ 2 d) for x = 0–0.5 and orthorhombic β-NaFeO 2 -type (space group Pna 2 1) for x = 0.6–1, both being built up from corner-sharing metal-centred tetrahedra and exhibiting complete disorder of Li and Ag atoms. Solid-state 7Li NMR spectra support the presence of unique Li sites. The substitution of Li for Ag atoms allows control of optical band gaps, which increase linearly from 2.7 eV to 3.6 eV. Second harmonic generation responses were measured to evaluate the potential of these compounds as infrared nonlinear optical materials. Li x Ag 1– x AlSe 2 undergoes a transformation from tetragonal to orthorhombic structures with increasing Li substitution, which also widens the band gap. [Display omitted] • The solid solution Li x Ag 1– x AlSe 2 was prepared at 850 °C. • A tetragonal-to-orthorhombic transformation takes place as Li content increases. • The band gap increases from 2.7 eV for AgAlSe 2 to 3.6 eV for LiAlSe 2. • Solid state 7Li NMR spectra reveal unique Li sites. [ABSTRACT FROM AUTHOR]

We report the discovery and characterization of three novel ternary compounds: TmCr 6 Ge 6 , YbCr 6 Ge 6 , and LuCr 6 Ge 6 , which complete the series of RCr 6 Ge 6 intermetallics with kagome lattice. Energy dispersive X-ray analysis revealed the off-stoichiometric composition of RCr 6 Ge 6 (R Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu). The powder XRD analysis with subsequent Rietveld refinement showed that investigated compounds crystallize in the SmMn 6 Sn 6 structure type (space group P 6/mmm), a disordered variant of the MgFe 6 Ge 6 -type, with a small number of vacancies at the rare earth (1 a) and germanium (2 e) sites and two additional 1 b and 2 e sites partially occupied by additional rare earth and germanium atoms, respectively. A tendency to structure ordering is observed with decreasing rare earth ionic radii. Electrical resistivity measurements indicate a metallic conductivity type for all studied compounds. Magnetic characterization reveals paramagnetic behavior for TmCr 6 Ge 6 and LuCr 6 Ge 6 , respectively, and suggests YbCr 6 Ge 6 as a ferrimagnetic material. The DFT modeling of RCr 6 Ge 6 shows a distinct high electron localization between Ge1 atoms, corresponding to strong covalent bonding. The calculated enthalpies of formation range from −18.56 kJ/mol for Gd to −19.60 for Tm compounds, while the distribution of the density of electronic states (DOS) confirms the metallic type of conductivity for all the series. The calculated elastic properties show brittle behavior and a high hardness level for the whole series. DFT modeling allowed us to reveal mechanisms of RCr 6 Ge 6 formation and the origin of disorder in their crystal structure. Electron localization function (ELF) and charge density of LuCr 6 Ge 6 indicating a covalent bonding character between Ge1-Ge1 atoms. [Display omitted] • RCr 6 Ge 6 compounds crystallize in the disordered SmMn 6 Sn 6 -type structure. • New ternary compounds with R Tm, Yb, and Lu were discovered. • Cr atoms contribute to the effective magnetic moments. • Electron deficiency of RCr 6 Ge 6 is the source of their structural disorder. [ABSTRACT FROM AUTHOR]

This paper presents a study of the crystal structure and crystal chemistry of the τ-Mg 32 (Al,Zn) 49 phase. We first performed DFT calculations to resolve conflicting data concerning the occupancy of site 2 a of the solid solution crystal structure. Subsequently, 16 ordered configurations derived from the mixing of Al/Zn on sites 24 g 1 , 24 g 2 and 48 h of the solid solution structure, as well as the mixing of Mg/Zn on site 12 e 1 were generated. We then used DFT calculations to derive the formation enthalpies of all the end-members of the solid solution, their elastic constants by imposing 51 finite deformations for each end-member , and their energies as a function of volume. These calculations were used in a Debye-Wang model (in Slater form) to calculate the heat capacities of the 16 end-members and to obtain in fine their Gibbs energies. At last, these calculations were used to support a thermodynamic model based on the Bragg-Williams approximation, enabling all mixed sites occupancies to be calculated at any temperature and chemical composition. For instance, the predictions we carried out at 633 K and 800 K are in very good agreement with the available measurements. On the basis of these new results, we have determined the chemical ordering of the solid solution over a very wide range of chemical composition and temperature, which has enabled us to propose a new sublattice model for the τ-Mg 32 (Al,Zn) 49 solid solution. This sublattice model is both simpler and more accurate than all the other models used in the literature since it agrees with the crystal structure and the crystal chemistry of the τ-Mg 32 (Al,Zn) 49 phase in a large range of temperature and chemical composition. Crystal chemistry of the τ-Mg 32 (Al,Zn) 49 solid solution: Chemical ordering quantification via the calculation of the Zn occupancy on the Al/Zn mixed sites of the structures using the Bragg-Williams approximation together with DFT calculations. [Display omitted] • We resolve the conflicting literature experimental data regarding the crystal structure of the τ-Mg 32 (Al,Zn) 49 solid solution using DFT calculations, showing that site 2 a is vacant. • The enthalpy of formation, elastic constants, heat capacity and Gibbs energy of 16 end-members of the τ-Mg 32 (Al,Zn) 49 solid solution were calculated using DFT. • Zn site fraction on the Al/Zn mixed sites of the τ-Mg 32 (Al,Zn) 49 solid solution were calculated at 633 K and 800 K and are in very good agreement with the available experimental data. • The chemical ordering of the τ-Mg 32 (Al,Zn) 49 solid solution has been quantified across a wide range of temperature and chemical composition. • The new SL model proposed in this work is consistent with both the crystal structure and the crystal chemistry of the solid solution, is simpler and more accurate than existing models. [ABSTRACT FROM AUTHOR]

RT-NaMn 1/2 Sn 1/2 S 2 was prepared by mechanochemical synthesis from a mixture of Na 2 S, MnS, and SnS 2. The crystal structure was determined from X-ray powder diffraction data. The chemical composition was confirmed by energy dispersive X-ray spectroscopy, and the electrical conductivity was measured using electrochemical impedance spectroscopy. The RT-NaMn 1/2 Sn 1/2 S 2 sample crystallizes with rock salt-type structure, space group Fm 3 ‾ m , a = 5.4368(2) Å, V = 160.71(2) Å3, and Z = 2. This sample exhibits an irreversible phase transition. It transforms into a high temperature phase, HT-NaMn 1/2 Sn 1/2 S 2 which crystallizes with α-NaFeO 2 -type structure, space group R 3 ‾ m , a = 3.7523 (4) Å, c = 19.883 (2) Å, V = 242.44 (4) Å3, and Z = 3. The structure was determined from single crystal XRD data. The electrical conductivities of the RT- and HT-forms are 2.5 × 10−8 S cm−1 (E a = 0.58 eV) and 3.3 × 10−7 S cm−1 (E a = 0.42 eV) at 25 °C, respectively. [Display omitted] • The cubic NaMn 1/2 Sn 1/2 S 2 phase was prepared by mechanochemical synthesis route. • The rock salt structure of the NaMn 1/2 Sn 1/2 S 2 phase was solved from XRPD data. • Irreversible cubic to trigonal phase transition was observed at high temperature. • The trigonal NaMn 1/2 Sn 1/2 S 2 phase is crystallizes with the α-NaFeO 2 -type structure. • The ionic conductivity of the trigonal phase is higher than the cubic phase. [ABSTRACT FROM AUTHOR]

The domain Sr 1-x Zr x F 2+2x studied at 670 °C between the limits 0.340 ≤ x ≤ 0.353 show the presence of a new phase Sr 17 Zr 9 F 70 and of modulated phases, all deriving from Ba 2 ZrF 8 structure type. In the same domain studied below 600 °C, Sr 17 Zr 9 F 70 tends to lose its long range ordering between Sr cations and Sr vacancies, tripling the b lattice parameter; moreover a new monoclinic superstructure S r 23 Zr 12 F 94 [ a = 3sinβ× a (Ba 2 ZrF 8); b = b (Ba 2 ZrF 8); c = c (Ba 2 ZrF 8), β = 105.31°] is also characterized. The homologous Hf phases are isostructural. With Pb, between 555 and 530 °C, another superstructure Pb 29 Zr 15 F 118 [ a = 5 × a (Ba 2 ZrF 8); b = b (Ba 2 ZrF 8); c = c (Ba 2 ZrF 8 ] and its isotypic Pb 29 Hf 15 F 118 are evidenced and their structure is solved in great part with a similar cationic disorder between Pb cations and Pb vacancies. Between 530 and 510 °C, a second much more complex superstructure exists but has not been characterized. Moreover, at 630 °C, single crystals of Pb 2 HfF 8 are obtained which allows to confirm that, contrary to Ba 2 ZrF 8 , Pb 2 HfF 8 is non-centrosymmetric (Pn2 1 a space group). but the atomic positions deviate only slightly from centrosymmetry. A general structural model for all these M′ 2p-1 M p F 8p-2 (p = 6, 9, 12, 15) microphases is developed. Sequence along the x -axis of zigzag rows in the microphases of M'F 2 -MF 4 (M' = Ba, Sr, Pb and M = Zr, Hf) systems. [Display omitted] • A series of M′ 2p-1 M p F 8p-2 microphases (p = 6, 9, 12, 15) is described with M' = Sr, Pb and M = Zr, Hf. • It corresponds to an ordered intergrowth between Ba 2 ZrF 8 and Sr 17 Zr 9 F 70 structure types. • A cationic disorder on some Sr or Pb sites appears at lower synthesis temperature which prevents a full refinement of the structures. • A general model of description of these microphases is proposed. [ABSTRACT FROM AUTHOR]

Two new silver-iron based phosphates AgFe 2 (PO 4) 2 F(H 2 O) 2 (1) with monoclinic P 2 1 / n and Ag 3 Fe 2 (PO 4)(HPO 4) 3 (2) with triclinic P -1 were synthesized by a conventional hydrothermal method, featuring a dimer structure and a twisted honeycomb-like lattice, respectively. XPS and BVS (Bond Valence Sum) calculations indicated only Fe3+ ions in both compounds, while FT-IR spectra proved the presence of [H 2 O] in 1 and [OH] groups in 2. Solid-state UV–vis–NIR diffuse reflectance spectra suggested their wide optical band gaps of 2.31 eV and 1.94 eV, respectively. Magnetic measurements indicated that both compounds display a long-range antiferromagnetic ordering at low temperature, showing the change of magnetic entropy of 9.59 J mol−1 K−1 in 1 and that of 14.87 J mol−1 K−1 in 2 , respectively. AgFe 2 (PO 4) 2 F(H 2 O) 2 exhibits a dimer structure and Ag 3 Fe 2 (PO 4)(HPO 4) 3 exhibits a honeycomb-like spin lattice. [Display omitted] • Two new phosphates AgFe 2 (PO 4) 2 F(H 2 O) 2 and Ag 3 Fe 2 (PO 4)(HPO 4) 3 are synthesized by a hydrothermal reaction. • AgFe 2 (PO 4) 2 F(H 2 O) 2 exhibits a dimer structure and Ag 3 Fe 2 (PO 4)(HPO 4) 3 exhibits a honeycomb-like spin lattice. • Both compounds possesses an antiferromagnetic ordering at low temperature with a field-induced magnetic transition. [ABSTRACT FROM AUTHOR]

This paper uses a simple method to synthesis four guanidine salts of nitrophenols and tetrazoles with low sensitivity (friction sensitivity and impact sensitivity) and high decomposition temperature. The crystal structures were tested by an X-ray single crystal diffractometer. Thermal decomposition behaviors were examined via differential scanning calorimetry (DSC), revealing decomposition temperatures of 295.04 °C, 332.57 °C, 252.51 °C, and 301.17 °C, all exceeding 250.00 °C. The detonation velocities and pressures were calculated using Explo5 based on the experimentally measured combustion heat. The detonation velocities for the four guanidine salts followed the order 4 (7667 m s−1)＞ 2 (6909 m s−1)＞ 3 (6722 m s−1)＞ 1 (6560 m s−1), and the explosion pressures were ranked as 4 (19.13 GPa)＞ 2 (17.72 GPa)＞ 1 (14.96 GPa)＞ 3 (12.43 GPa). The combustion heats were measured using oxygen bomb calorimetry and were found to be 2 (11.85 kJ g⁻1) > 3 (11.66 kJ g⁻1) > 4 (11.31 kJ g⁻1) > 1 (10.57 kJ g⁻1). The impact sensitivity was greater than 100 J, and the friction sensitivity was greater than 360 N. Given these advantages, it is anticipated that these compounds could have applications in propellants and gas generators. [Display omitted] • Four guanidine salts of nitrophenols and tetrazoles with low sensitivity and high decomposition temperature were synthesized. • The crystal structures were tested by an X-single crystal diffractometer. • The combustion heats were tested through the oxygen bomb calorimetry, and their detonation performance (D and P) have been calculated. [ABSTRACT FROM AUTHOR]

Two novel ternary intermetallic compounds Ce 23 Ru 7 In 4 and Pr 23 Ru 7 In 4 were synthesized by arc melting of components and subsequent annealing at 600 °C. Both compounds crystallize in a hexagonal cell, with structure type Pr 23 Ir 7 Mg 4 , space group P6 3 mc (№ 186), Pearson symbol hP 68, Z = 2, the cell parameters: a = 9.861(5) Å, c = 22.520(12) Å (Ce); a = 9.9260(7) Å, c = 22.4109(2) Å (Pr). The structure of Ce 23 Ru 7 In 4 was determined by single-crystal X-ray diffraction and the structure of Pr 23 Ru 7 In 4 was determined by the Rietveld method using powder X-ray diffraction pattern. Compound Ce 23 Ru 7+x In 4-x exist in the homogeneity range 0 ≤ x ≤ 3. An essential feature of compound Ce 23 Ru 7 In 4 is the presence of abnormally short distances Ce–Ru (2.637 Å, 2.735 Å). The compound Pr 23 Ru 7 In 4 melts incongruently and compound Ce 23 Ru 7 In 4 melts congruently at temperatures 756 and 683°С respectively. The Pr 23 Ru 7 In 4 compound is characterized by the presence of a magnetic transition at 12 K. The observed magnetic transition is most likely indicative of a transition to the spin glass state. Crystal structure of the compound Ce 23 Ru 7 In 4 , layer of Ru-centered trigonal prisms with Ce atoms at the vertices on the ab plane and Ce–Ru distances in such prisms in Å. [Display omitted] • Novel ternary intermetallic compounds R 23 Ru 7 In 4 (R Ce, Pr) were prepared. • Anomalously short Ce–Ru distances (2.637 Å, 2.735 Å) were found in the Ce 23 Ru 7 In 4 structure. • Intermetallic compound Ce 23 Ru 7 In 4 melts congruently, and compound Pr 23 Ru 7 In 4 melts incongruently. • The Pr 23 Ru 7 In 4 compound is characterized by the presence of a magnetic transition at 12 K. [ABSTRACT FROM AUTHOR]

This article reports a new perovskite compound Ca 6 Sb 2 O 11. The X-ray powder diffraction technique was used to analyze its crystal structure. The results show that Ca 6 Sb 2 O 11 has a tetragonal structure with the I 4/ m space group, and the lattice parameters are a = b = 5.658 (1) Å, c = 7.984 (1) Å, α = β = γ = 90°. It exhibits a typical A 4 B' 2 B″ 2 X 12- x anoxic multi-perovskite structure with rock-salt ordering of the B-site cations. The compound's chemical composition and valence states were characterized through scanning electron microscopy-energy dispersion spectrum (SEM-EDS) and X-ray photoelectron spectroscopy (XPS). The presence of oxygen vacancies was confirmed by electron paramagnetic resonance (EPR) spectroscopy. A chemical and structure transition temperature and the full melting temperature of Ca 6 Sb 2 O 11 were measured, with values of 1515 ± 3 K and 1720 ± 3 K, respectively. The density functional theory (DFT)-electron structure calculation results show that Ca 6 Sb 2 O 11 is an indirect wide-band gap (∼4.47 eV) semiconductor material, which agrees well with the experimental value (∼4.38 eV) obtained through diffuse reflection spectroscopy (DRS). Moreover, the top of the valence band and bottom of the conduction band are mainly contributed to by O-2p and Ca-3d states, respectively. The synthesis of the new perovskite compound, Ca 6 Sb 2 O 11 , requires three steps. First, the raw materials, Sb 2 O 3 and CaO, are mixed in a specific proportion. Then, the Ca 6 Sb 2 O 11 compound can be synthesized by roasting the sample at 773 K for 3 days, followed by roasting it at 1173 K for 40 days, and finally at 1586 K for 12 h. The crystal structure of the compound belongs to the tetragonal space group I 4/ m. The band structure of the compound was obtained through DFT calculation, indicating that it is an indirect bandgap semiconductor material. [Display omitted] • The new compound Ca 6 Sb 2 O 11 was synthesized and its crystal structure was analyzed. • The electronic structure of Ca 6 Sb 2 O 11 was explored by DFT calculation. • Anoxic phase Ca 6 Sb 2 O 11- x (x = 0.53) can transform into Ca 6 Sb 2 O 11 at high temperatures. [ABSTRACT FROM AUTHOR]

The new CsM x W 2-x O 6 (M = Sn, V and Mo, x = 0–0.5) solid solutions with β-pyrochlore structure have been prepared by sol-gel synthesis. The chemical composition has been investigated by SEM with X-ray microanalysis and X-ray photoelectron spectroscopy. It was found that the W atom in structure has mixed valence state 5+ and 6+, Sn and Mo has only 4+ and 6+, respectively, and V possesses mix of 5+ and 3+ dependence on composition. Thus the crystal structure has been determined by X-ray diffraction analysis, and the CsM x W 2-x O 6 (M = Sn and Mo, x = 0–0.5) compounds have the monotonous changing in unit cell parameter, whereas CsV x W 2-x O 6 (x = 0–0.25) has complex dependence due to different V atom ratio. The electronic structure has been studied by UV–vis spectroscopy and XPS analysis and approximated by simple theoretical calculation based on atomic electronegativity. The photocatalytic activity has been investigated using reaction of methylene blue decomposition under visible and UV irradiation, and the possible degradation pathway was supposed by HR-LCMS analysis. The relation between electronic structure and photocatalytic activity has been discussed. The new β-pyrochlore compounds with composition of CsM x W 2-x O 6 (M = Sn, V and Mo, x = 0–0.5) have been prepared by sol-gel method. The highest MB conversion degree in visible light was observed for CsSn 0.25 W 1.75 O 6 , CsMo 0.25 W 1.75 O 6 , CsMo 0.5 W 1.5 O 6 and CsMo 0.1 W 1.9 O 6. According to HR-LCMS analysis, the composition of CsSn 0.25 W 1.75 O 6 shows the deepest MB decomposition, without any peaks of initial molecules, and leads to formation simple aromatic and non-aromatic compounds. [Display omitted] • The new β-pyrochlore compounds with composition of CsM x W 2-x O 6 (M = Sn, V and Mo, x = 0–0.5) have been prepared by sol-gel method. • The valence state of W, Sn, V atoms in octahedral framework was determined by XPS method. • The electronic structure of obtained compounds has been investigated experimentally. • The phototcatalytic decomposition of MB has been investigated under UV and visible light. • The MB decomposition products have been defined. [ABSTRACT FROM AUTHOR]

Semiconductor coordination polymers have garnered significant attention as photocatalysts for wastewater treatment owing to their adaptable structure, expansive specific surface area, and outstanding selectivity, stability, and sensitivity. In this study, coordination polymer [Ni(ppda) (tib) (H 2 O)]·H 2 O was synthesized utilizing flexible phenyldiacetic acid (H 2 ppda) and rigid 1,3,5-tris(1-imidazolyl)benzene (tib). Crystal structure analysis revealed that the three-linked tib ligands and the central Ni(II) ion create a wavy 2D surface. Additionally, cis -ppda2- ligands form a 1D wave chain alongside central Ni(II), which traverse through a 2D layer. Adjacent layers are interlaced via ppda2−, resulting in a complex 3D supramolecular structure. The fundamental framework of [Ni(ppda) (tib) (H 2 O)]·H 2 O exhibits stability up to 316 °C and remains stable over 5 cycles, with a band gap energy of 2.9 eV, rendering it a viable candidate for catalytic applications. In aqueous systems, [Ni(ppda) (tib) (H 2 O)]·H 2 O demonstrates efficient photocatalytic degradation of Indigo Carmine (IC), achieving a degradation rate of 98.5% and a reaction rate of 0.027 min−1, showcasing commendable selectivity and semiconductor properties. The primary photocatalytic degradation mechanism involves the synergistic formation of ·OH and ·O 2 - active species through the interaction between [Ni(ppda) (tib) (H 2 O)]·H 2 O and H 2 O 2 , facilitating the oxidative degradation of dye molecules. The newly synthesized photocatalyst [Ni(tib) (ppda) (H 2 O)]·H 2 O boasts a specific surface area of 22 m2/g and an E g of 2.9 eV [Ni(tib) (ppda) (H 2 O)]·H 2 O demonstrates exceptional photocatalytic degradation capabilities, achieving a remarkable degradation rate of 98.5% for IC, accompanied by a reaction rate of 0.027 min−1. The primary photocatalytic degradation mechanism involves the synergistic formation of ·OH and ·O 2 - active species through the interaction between [Ni(tib) (ppda) (H 2 O)]·H 2 O and H 2 O 2 , facilitating the oxidative degradation of dye molecules. [Display omitted] • The newly synthesized photocatalyst [Ni(tib) (ppda) (H 2 O)]·H 2 O boasts a specific surface area of 22 m2/g and E g of 2.9 eV. • [Ni(tib) (ppda) (H 2 O)]·H 2 O demonstrates exceptional photocatalytic degradation capabilities, achieving a remarkable degradation rate of 98.5% for IC, accompanied by a reaction rate of 0.027 min−1. • The primary photocatalytic degradation mechanism involves the synergistic formation of ·OH and ·O 2 - active species between [Ni(tib) (ppda) (H 2 O)]·H 2 O and H 2 O 2 , facilitating the oxidative degradation of dye molecules. [ABSTRACT FROM AUTHOR]

Understanding the properties of transition metal materials requires consideration of the competition between the various types of electrons that comprise the system, whether they be delocalized and metallic, localized and magnetic, or localized and bonded. Here we report the refined crystal structure determination and physical properties of the two-dimensional layered compound TaOCl 2. Within each layer we find a strong in-plane dimerization of Ta atoms perpendicular to the Ta-O-Ta chains, with significant disorder in the positioning of dimers in adjacent layers, suggesting that the free electron of each Ta localizes in Ta-Ta bonds. This is supported by resistivity measurements (ρ 300K = 4.4*108 Ω-cm) as well as featureless, temperature-independent magnetic susceptibility up to T = 750 K. Analysis of the phonon contribution to specific heat shows the presence of a localized Einstein mode with T E = 175 K, attributed to the localized vibrations of the Ta-Ta dimers. Density functional theory calculations show that the magnitude of the Ta displacements (0.24 Å) has a dramatic effect on the electronic structure, changing from a metal with a bandwidth of 3.2 eV to an insulator with a flat band just below E F. Our results show how direct exchange interactions between Ta atoms that are relatively far from each other can still play a central role in the behavior of 5d transition metal compounds, taking advantage of the extended 5d atomic orbitals, and produce localized dimers with a bond distance of approximately 2.84 Å. Illustrating the discovery of and modeling disorder in the crystal structure of TaOCl 2. [Display omitted] • In-plane disorder leading to Ta-Ta dimerization discovered in crystal structure. • Dimerization significantly affects physical properties. • Significant electrical resistance observed, at odds with predicted electronic band structure of undistorted crystal structure. • Significant potential for tuning of crystal structure and properties. [ABSTRACT FROM AUTHOR]

The new ternary compound Zr 7 Pd 7- x Ga 3+ x (0 ≤ x ≤ 1.8) was synthesized by arc melting the elements under argon and subsequent annealing the ingots at 870 K for 720 h. The polycrystalline samples were characterized by powder X-ray diffraction (XRD) and the crystal structure of the compound was determined from single crystal X-ray diffraction data. Zr 7 Pd 7 Ga 3 crystallizes with a ternary version of the Zr 7 Ni 10 type of structure exhibiting statistical mixtures of palladium and gallium atoms on three crystallographically independent nickel sites (oS 68, Cmce , a = 12.997(3), b = 9.623(2), c = 9.630(2) Ǻ, Z = 4, R 1 = 0.033, w R 2 = 0.067 for 719 unique reflections with I o > 2 σ(I o) and 48 refined parameters). The crystal structure of Zr 7 Pd 7 Ga 3 is represented by a 3D Pd–Ga framework built of sinusoidal layers of Pd and Ga stacking along the b axis sandwiching the Zr atoms. The homogeneity range of the compound Zr 7 Pd 7– x Ga 3+ x has been refined from powder XRD and EDX data: 0 ≤ x ≤ 1.8; variation of the lattice parameters is the following: a = 13.0174(8)–12.904(3), b = 9.6306(8)–9.559(8), c = 9.6348(8)–9.700(5) Å. Electronic structure calculations have been performed for an idealized model Zr 7 Pd 10 as well as a model compound Zr 7 Pd 6.5 Ga 3.5 revealing that the Ga-free Zr 7 Pd 10 is significantly destabilized by strong Pd–Pd anti-bonding interactions. Substitution of Pd by Ga reduces those, stabilizing Zr 7 (Pd,Ga) 10 which features strong heteroatomic bonding between Zr and the Pd/Ga substructure, putting it into the class of polar intermetallics. Sinusoidal Pd/Ga layers stacking along the b axis in the crystal structure of Zr 7 Pd 7–x Ga 3+x. [Display omitted] • Alloy formation in the Zr–Pd–Ga system have been investigated at 870 K. • The new ternary gallide Zr 7 Pd 7-x Ga 3+x (0 ≤ x ≤ 1.8) has been identified. • The crystal structure of Zr 7 Pd 7-x Ga 3+x (0 ≤ x ≤ 1.8) has been established. • The electronic structure and bonding patterns of Zr 7 Pd 7-x Ga 3+x (0 ≤ x ≤ 1.8) have been calculated and analyzed. [ABSTRACT FROM AUTHOR]

A novel three-dimensional sodium manganese fluorooxalate, Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O, has been obtained by an ionic-liquid-assisted solvothermal method. Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O crystallizes in the triclinic P 1 ‾ space group with unit cell parameters of a = 7.9129(4) Å, b = 8.8497(4) Å, c = 8.9252(5) Å, α = 74.623(4) o, β = 72.361(5) o, γ = 78.193(4) o, and Z = 2. The basic structural units are Mn1O 6 F and Mn2O 5 F polyhedra, which are linked by sharing C 2 O 4 groups and F atoms to build a three-dimensional framework [ Mn 4 (C 2 O 4) 5 F 2 ] ∞ 3 4 − with Na+ and H 2 O occupying the pores. The band gap obtained by UV–Vis–NIR diffuse reflectance is 3.24 eV. In addition, Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O delivers a moderate birefringence of 0.064@550 nm. A novel three-dimensional fluorooxalate Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O delivers a moderate birefringence. [Display omitted] • A new fluorooxalate compound Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O is solvothermally synthesized. • Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O presents a three-dimensional framework [ Mn 4 (C 2 O 4) 5 F 2 ] ∞ 3 4 − . • Na 2 Mn 2 (C 2 O 4) 2.5 F·2H 2 O delivers a moderate birefringence of 0.064@550 nm. [ABSTRACT FROM AUTHOR]

Zn2+ and Mn2+ co-doped LiFe 0.9 Zn 0.1-x Mn x PO 4 (where x = 0, 0.05, 0.075, 0.1) composites are synthesized by a simple one-step hydrothermal method. The composition, structure, morphology and electrochemical properties of the materials are fully characterized using XRD, SEM, TEM, EDS, CV and AC impedance tests. The results show that the co-doping of Zn2+ and Mn2+ preserves the olivine structure of LiFePO 4 and also stabilizes the crystal structure, reduces the charge transfer resistance and improves the Li+ diffusion rate. When the initial specific capacity of the cathode material with the doping ratio of Zn = 0.025 and Mn = 0.075 is 161.8 mAh·g−1, the discharge specific capacity after 200 cycles is still as high as 157.8 mAh·g−1 with a capacity retention of 97.5 %, which is obviously better than the rest of the materials. [Display omitted] • The selected method is simple and the experiment is highly reproducible. • Selection of zinc and manganese salts with excellent water solubility. • Mn2+ can support the crystal structure and increase the crystal plane spacing. • Zn2+ improves the cyclic stability of the material. [ABSTRACT FROM AUTHOR]

In this study, we present the crystallographic and magnetic characterization of a new intermetallic compound Sm 2 PdGe 3, which was synthetized by a two stage method employing an eutectic alloy. The investigations carried out exhibited, that Sm 2 PdGe 3 crystallize in AlB 2 -type structure with lattice parameters a = 4.2189(1) Å and c = 4.1031(2) Å. This compound can be classified as a cluster-glass with a spin freezing temperature T f = 10.5 K. Furthermore, there were carried out the analysis of the role of the rare earth (RE) elements on the structural parameters of RE 2 PdGe 3 and draw a correlation between the RE radius and the unit cell parameters. We show that a deviation from the ideal 1:3 Pd:Ge ratio is necessary to synthesize RE 2 PdGe 3 with smaller RE elements. A crystal structure of a new intermetallic compounds Sm 2 PdGe 3. [Display omitted] • A new member of RE 2 PdGe 3 family were successfully synthetized employing a two-stage methods based on a eutectic alloy. • Sm 2 PdGe 3 crystallize in a disordered variant of AlB 2 – derived hexagonal structure with a space group P6/mmm (no. 191). • Spin glass like behavior was observed with a freezing temperature equal T f = 8.0 K for Sm 2 PdGe 3. • It was observed that in the RE 2 PdGe 3 family the volume of a unit cell decreases with the shrinkage of RE ionic radius. • Most of RE 2 PdGe 3 with magnetic RE elements exhibit a cluster glass behavior, due to the coexistence of structural disorder and magnetic frustration. [ABSTRACT FROM AUTHOR]

This study investigated the crystal structure, P–C isotherm, and cyclic properties of YNi 3. We discovered that hydrogen-induced amorphization (HIA) was appeared in three cycles of P–C isotherm at 303 K, but it was not observed at 273 K. An analysis of the three cycles at 303 K revealed a 55 % decrease in hydrogen capacity as compared to the first cycle. To enhance the hydrogenation properties, Mn was substituted for Ni. X-ray Rietveld refinements on YNi 2·7 Mn 0·3 H 3.8 reveal that the hydride phase retains the PuNi 3 -type structure of the original alloy. The values of a, c , the unit cell, the MgZn 2 -type cell, and the CaCu 5 -type cell expanded 5.6 %, 9.3 %, 21.9 %, 25.0 %, and 18.8 % from the original alloy. The results indicated that YNi 2·7 Mn 0.3 retained 91 % of its initial hydrogen capacity after three cycles at 303 K. After 120 cycles in the cyclic test, YNi 3 and YNi 2·7 Mn 0.3 retained 42 % and 90 % of their initial capacity, respectively. The XRD profile of YNi 3 after 120 absorption-desorption cycles revealed significant peak broadening. Similarly, peak broadening was also observed in the XRD profile of YNi 2·8 Mn 0.2 after 120 cycles. In comparison, the XRD profile of YNi 2·7 Mn 0.3 after 120 cycles remained relatively unchanged from its initial state. It was observed that YNi 2·7 Mn 0.3 experienced less lattice strain during hydrogenation than YNi 2·8 Mn 0.2. The retention rate of YNi 3 , YNi 2·8 Mn 0.2 and YNi 2·7 Mn 0.3 showed a moderate decrease with increasing cycles, maintaining 45 %, 62 % and 90 % at 120 cycles. [Display omitted] • Hydrogen-induced amorphization (HIA) was not observed at 273 K. • Plateau pressure decreased with increasing Mn content. • Mn substitution improved cyclic properties. • YNi 2·7 Mn 0.3 retained 90 % hydrogen capacity after 120 cycles at 303 K. • Neutron diffraction identified Mn at 6c and 18 h sites in YNi 2·7 Mn 0.3. [ABSTRACT FROM AUTHOR]

A new cerium phosphite-oxalate, [Ce 2 (H 2 PO 3)(C 2 O 4) 4 ](C 6 N 2 H 16)·H 3 O·3H 2 O (1), was prepared under solvothermal condition using 1-ethylpiperazine as template. Single-crystal X-ray diffraction proves that compound 1 has a new three-dimensional (3D) structure constructed with CeO 9 polyhedra, [C 2 O 4 2−] ligands and [H 2 PO 3 −] groups. View along the b-axis, 1-ethylpiperazine cations and water molecules alternately located in the adjacent 12-ring channels. Impedance analysis shows that the proton conductivity of 1 is up to 9.17 × 10−4 S cm−1 at 75 °C and 98 % relative humidity (RH). Stability test reveals that proton conduction has good persistence at the highest temperature and humidity. This suggests that compound 1 possesses promising proton conductivity property, making it into a potential candidate material for proton exchange membranes. A new 3D open framework cerium phosphite-oxalate compound, [Ce 2 (H 2 PO 3)(C 2 O 4) 4 ](C 6 N 2 H 16)·H 3 O·3H 2 O (1), has been solvothermally synthesized. Compound 1 shows high proton conductivity (σ = 9.17 × 10−4 S cm−1, at 75 °C and 98 % RH). Stability test reveals that proton conduction has good persistence at the highest temperature and humidity. [Display omitted] • A 3D cerium phosphite-oxalate was successfully prepared, which shows high proton conductivity (σ = 9.17 × 10−4 S cm−1 S·cm−1, at 75 °C and 98 % RH). • A 10-h proton conductivity stability test over time showed that the proton conduction of 1 has good durability (75 °C and 98 % RH). • A 3D cerium phosphite-oxalate was successfully prepared.It shows high proton conductivity. • Stability test reveals that proton conduction has good persistence. [ABSTRACT FROM AUTHOR]

In this paper, the crystal structure, physical properties, photoelectric conversion efficiency and large-area development of CsPbI 3 all-inorganic perovskite solar cells are comprehensively analyzed. The research results of the material in photoelectric conversion efficiency, large-area development and preparation technology are summarized. In addition, through theoretical prediction and simulation, this study simulated a CsPbI 3 all-inorganic perovskite solar cell with a photoelectric conversion efficiency of 28.29 %, which provided a theoretical basis for the preparation of high-performance devices. In this paper, the physical properties, photoelectric conversion efficiency, large area and preparation methods of CsPbI 3 all-inorganic perovskite solar cells are summarized in detail. In addition, the theoretical efficiency of the device was predicted, and the CsPbI 3 all-inorganic perovskite solar cell with a theoretical photoelectric conversion efficiency of 28.29 % was successfully obtained. [Display omitted] • CsPbI 3 all-inorganic perovskite solar cells. • Physical Properties of CsPbI 3 Materials. • Research status and preparation methods. • The theoretical efficiency of simulation prediction reaches 28.29 %. • Challenge and strategies. [ABSTRACT FROM AUTHOR]

Tin-oxo clusters, as molecular model compounds of tin oxide materials, have attracted increasing attention. Although various tin-oxo clusters have been obtained, the systemic studies on ligand functionalization of tin-oxo clusters remain to be well developed. In this study, we adopted 3-aminopyrazine-2-carboxylic acid (HAPZC) as the functionalized ligand, and successfully synthesized a novel tin-oxo cluster [(n -BuSn) 12 (OH) 6 O 14 (APZC) 2 ]·2H 2 O (CTGU-SnC-3). Due to the functionalization of the APZC ligands, the structure and charge of Sn 12 cage in CTGU-SnC-3 are all different from those of reported cationic football cage. This Sn 12 cage in CTGU-SnC-3 presents the interesting low-symmetrical football framework with the functionalized ligands. Different from the reported cationic football cages, the CTGU-SnC-3 is charge-neutral structure without any counteranions. Moreover, the CTGU-SnC-3 exhibits hydrophobic behavior and catalytic activity in electrocatalytic CO 2 reduction reaction. The novel low-symmetrical charge-neutral football framework CTGU-SnC-3 was successfully synthesized via the functionalization of the ligands. It exhibits hydrophobic behavior and good catalytic activity in electrocatalytic CO 2 reduction reaction. [Display omitted] • A novel low-symmetrical tin-oxo football cage CTGU-SnC-3 was successfully constructed via the functionalization of the ligands. • The Sn 12 cage in CTGU-SnC-3 is charge-neutral structure without any counteranions, which is different from the reported typical cationic football cages. • The CTGU-SnC-3 exhibits hydrophobic behavior and good catalytic activity in electrocatalytic CO 2 reduction reaction. [ABSTRACT FROM AUTHOR]

Integrating metal-organic frameworks (MOFs) with transition hydroxides has the potential to enhance the inadequate electronic conductivity and address the slow diffusion of MOF materials in electrochemical applications. Herein, we synthesized a 2D Cu-MOF and successfully prepared a Cu-MOF@Co(OH) 2 heterostructure using a one-step hydrothermal method on a Co(OH) 2 /NF (nickel foam) substrate. The hybrid Cu-MOF@Co(OH) 2 material exhibits high electrochemical reactivity, resulting in enhanced pseudocapacitor performance, with a specific capacitance of 2039.8 mF cm−2 at a current density of 1.0 mA cm−2. In addition, an asymmetric two-electrode cell was constructed using Cu-MOF@Co(OH) 2 /NF and activated carbon (AC)/NF, exhibiting a specific capacitance of 444.5 mF cm−2 at a current density of 1.0 mA cm−2, and demonstrating decent cycling durability with 90.1 % retention after 2000 cycles. One 2D Cu-MOF with MOF-110 analogs has been obtained and crystallographically characterized. The Cu-MOF@Co(OH) 2 heterostructure acted as asymmetric supercapacitor electrode material, which delivered enhance pseudocapacitor performance. Besides, the asymmetric two-electrode Cu-MOF@Co(OH) 2 //AC devices possessed the good specific capacitance and cycling durability. [Display omitted] • One 2D Cu-MOF with MOF-110 analogs has been synthesized and crystallographically characterized. • The Cu-MOF@Co(OH) 2 hybrid material has been fabricated, characterized and showed enhanced pseudocapacitor performance. • The asymmetric two-electrode Cu-MOF@Co(OH) 2 //AC devices possessed the good specific capacitance and cycling durability. [ABSTRACT FROM AUTHOR]

Hexagonal perovskite manganite has attracted much attention due to its rich structural chemistry and magnetic properties. The transformation between Ba M x Mn 1− x O 3 polymorphs can be caused by the change in substitution level or oxygen vacancies. In this study, we find a new polymorph change from 10 H Ba 5 Sb 0.7 Mn 4.3 O 15 (P 6 3 / mmc) to 12 R Ba 4 Sb 0.85 Mn 3.15 O 12 (R 3 ‾ m) via a 'topochemical' reaction with excess Sb 2 O 3. The 10 H Ba 5 Sb 0.7 Mn 4.3 O 15 structure contains BaO 3 layers in a (cchhh) 2 sequence and face-shared MnO 6 tetramers (Mn 4 clusters), while the 12 R Ba 4 Sb 0.85 Mn 3.15 O 12 structure consists of BaO 3 layers in a (cchh) 3 stacking and face-shared MnO 6 trimers (Mn 3 clusters). The 10 H → 12 R phase conversion accompanies the exsolution of the Mn 3 O 4 phase in trace amounts. For both 10 H Ba 5 Sb 0.71 Mn 4.29 O 15 and 12 R Ba 4 Sb 0.85 Mn 3.15 O 12 , the Mn3+ cation on the corner-shared octahedra at M 1 sites mediated competing ferromagnetic and antiferromagnetic exchanges between the magnetic Mn 3 and Mn 4 clusters, leading to spin-freezing transition at T F ≈ 11–15 K. The 10 H → 12 R phase change leads to an abrupt change of 2 K saturation moment from M s ≈ 0.1 μ B of 10 H Ba 5 Sb 0.71 Mn 4.29 O 15 to M s ≈ 1.75 μ B of 12 R Ba 4 Sb 0.85 Mn 3.15 O 12. A polymorphic change from 10 H Ba 5 Sb 0.7 Mn 4.3 O 15 to12 R Ba 4 Sb 0.85 Mn 3.15 O 12 phase is realized via a 'topochemical' reaction with excess Sb 2 O 3 , and accompany with the exsolution of Mn 3 O 4 and a sudden jump in saturation moment at 2 K. [Display omitted] • A 10 H.→ 12 R phase is realized via a 'topochemical' reaction between 10 H Ba 5 Sb 0.7 Mn 4.3 O 15 and excess Sb 2 O 3. • The 10 H.→ 12 R phase change accompanies the exsolution of Mn 3 O 4 phase. • The 12 R Ba 4 Sb 0.85 Mn 3.15 O 12 material consists of BaO 3 layers in a (cchh) 3 stacking and face-shared MnO 6 trimers. • The 10 H and 12 R phase display spin-freezing transition at T F ≈ 11–15 K. • The 10 H.→ 12 R phase change leads to an abrupt change of 2 K saturation moment from 0.1 μ B to M s ≈ 1.75 μ B. [ABSTRACT FROM AUTHOR]

We examined here how different ratios of precursors, temperature, time, and synthesis environment affected the crystal structure, texture, and CO 2 /N 2 sorption behavior of the ZIF-300 samples synthesized. We found that a higher bmim/meIm molar ratio resulted in larger particle size, increased pore volume, and higher BET surface area due to a more crystalline structure and well-shaped pore structure. This was attributed to a decrease in the pH of the synthesis solution caused by the higher bmim/meIm molar ratio, which lowered the ζ potential and reduced electrostatic repulsion between particles, leading to the formation of larger particles with a more crystalline structure. Increasing the temperature of the synthesis solution resulted in smaller particles due to a decrease in supersaturation levels and the formation of smaller nuclei. The duration of synthesis had a positive effect on particle size as both growth and aggregation of smaller particles occurred over time. NMP and DMA were found to be unsuitable synthesis environments as they produced large particles with poor gas sorption performance. In terms of texture, ZIF-300 samples synthesized with a higher bmim/meIm molar ratio and at lower temperatures exhibited higher BET surface area and pore volume compared to other samples. Additionally, samples synthesized with a molar ratio of bmim/meIm = 4/1 and 2/1 showed better selectivity for CO 2 /N 2 solubility compared to similar cases reported in previous studies. Effect of different ratios of precursors, temperature, time, and synthesis environment on crystal structure and textural behavior of the different ZIF-300 samples. [Display omitted] • Factors studied on ZIF-300 samples: crystal structure, texture, CO 2 /N 2 sorption behavior. • Higher bmim/meIm ratio = larger particle size, increased pore volume, higher BET surface area. • Higher synthesis temperature = smaller particles due to decreased supersaturation levels. • Longer synthesis duration = positive effect on particle size due to growth and aggregation. • NMP and DMA unsuitable synthesis environments: large particles, poor gas sorption performance. [ABSTRACT FROM AUTHOR]

The polycrystalline Yb 23 Cu 7 Mg 4 -type {Gd, Tb} 23 Ni 7 In 4 compounds (space group P 6 3 / mmc , N 194, hP 68) were prepared by arc melting with following annealing. They exhibit ferromagnetic ordering below Curie temperature T C = 142 K for Gd 23 Ni 7 In 4 and T C = 112 K for Tb 23 Ni 7 In 4 , respectively. A field-sensitive antiferromagnetic transformation takes place around 90 K in Gd 23 Ni 7 In 4 and 106 K in Tb 26 Ni 7 In 4 , respectively. Down to 10 K, they are soft ferromagnets with magnetizations of 4.7 μ B /Gd for Gd 23 Ni 7 In 4 and 5.7 μ B /Tb for Tb 23 Ni 7 In 4 in 90 kOe. In a field change of 50 kOe around T C , Gd 23 Ni 7 In 4 shows magnetic entropy change of −4.7 J/kg⋅K at 133–143 K, while Tb 23 Ni 7 In 4 shows magnetic entropy change of −5.4 J/kg⋅K at 109 K. The magnetic ordering and magnetocaloric effects of arc-melted polycrystalline Yb 23 Cu 7 Mg 4 -type {Gd, Tb} 23 Ni 7 In 4 compounds (space group P 6 3 / mmc , N 194, hP 68) have been investigated using magnetic measurements in fields up to 90 kOe. They exhibit ferromagnetic ordering below Curie temperature T C = 142 K for Gd 23 Ni 7 In 4 and T C = 112 K for Tb 23 Ni 7 In 4 , respectively. A field-sensitive antiferromagnetic transformation takes place around 90 K in Gd 23 Ni 7 In 4 and 106 K in Tb 26 Ni 7 In 4 , respectively. Down to 10 K, they are soft ferromagnets with magnetizations of 4.7 μ B /Gd for Gd 23 Ni 7 In 4 and 5.7 μ B /Tb for Tb 23 Ni 7 In 4 in 90 kOe. In a field change of 50 kOe around T C , Gd 23 Ni 7 In 4 shows magnetic entropy change of −4.7 J/kg⋅K at 133–143 K, while Tb 23 Ni 7 In 4 shows magnetic entropy change of −5.4 J/kg⋅K at 109 K. [Display omitted] • Yb 23 Cu 7 Mg 4 -type Gd 23 Ni 7 In 4 and Tb 23 Ni 7 In 4 prepared via arc-furnace melting/annealing. • Gd 23 Ni 7 In 4 shows ferromagnetic ordering at 142 K and Tb 23 Ni 7 In 4 at 112 K. • They exhibit field sensitive LT antiferromagnetic-like transformation of magnetic ordering. • Down to 10 K, these compounds are soft non-collinear ferromagnets in fields up to 90 kOe. • Gd 23 Ni 7 In 4 has magnetic entropy change of −4.7 J/kg⋅K around T C (field change 0-50 kOe). • Tb 23 Ni 7 In 4 shows magnetic entropy change of −5.4 J/kg⋅K at T C (field change 0-50 kOe). [ABSTRACT FROM AUTHOR]

In this study, a new compound 1 with the formula as [Cd((S/R)-ptz) 2 ] n was solvothermal synthesized from Cd(II) salt and (S/R)-5-(pyrrolidin-2-yl)-1H-tetrazole ((S/R)-ptzH) ligand. Compound 1 exhibits good solvent stability and acid-base stability. Notably, 1 displays yellow room-temperature phosphorescence that can be visually observed for approximately 2 s, marking a significant milestone in metal-organic frameworks (MOFs) incorporating proline-tetrazole ligand. Presented here is a new room-temperature phosphorescent Cd-MOF with 2 s long afterglow. [Display omitted] • A new Cd-metal-organic framework based on proline-tetrazole exhibits excellent solvent stability and acid-base stability. • It displays yellow room-temperature phosphorescence (RTP) that can be visually observed for approximately 2 s. • It marks a significant milestone in MOFs incorporating proline-tetrazole ligand. [ABSTRACT FROM AUTHOR]

Different sol-gel routes were tested to synthesize polycrystalline material of K 8 CaSi 10 O 25. The best result in terms of phase purity was obtained using combustion synthesis with glycine as fuel. Single crystals were obtained from the devitrification of a glass. Cyclic single-crystal diffraction studies were carried out within the temperature range of ambient conditions to 873 K with different cooling rates. The crystal structure (space group R 3 c) at ambient temperature was consistent with previous investigations (a = 11.1135(6) Å, c = 21.9286(14) Å, V = 2345.5(2) Å3). A new high-temperature polymorph was discovered, showing the following crystallographic data at 873 K: space group R 3 ‾ m , a = 11.2251(8) Å, c = 11.1789(9) Å, V = 1219.9(2) Å3. On heating, an incommensurately modulated structure was observed between the two aforementioned modifications. The standard third-law entropy was determined from low-temperature C p 's measured by relaxation calorimetry and amounts to S°(298 K) = 898.7 ± 6.3 J mol−1 K−1. Polycrystalline material and single-crystals of K 8 CaSi 10 O 25 were synthesized and its crystal structure at ambient conditions was determined. In-situ single-crystal diffraction at elevated temperatures revealed the presence of two high-temperature polymorphs including an incommensurately modulated phase. The structure of the non-modulated HT-form stable at 873 K was solved. Heat capacities between 2 and 600 K as well as the standard third-law entropy S° at 298.15 K were measured which are of importance for thermodynamic modeling of the ternary system K 2 O–CaO–SiO 2. [Display omitted] • Synthesis of polycrystalline K 8 CaSi 10 O 25 using a solution combustion route. • Structure represents a tetrahedral-octahedral framework with K-ions occupying channels of the network. • Upon heating, two phase transitions have been observed including one modulated structure. • Structural evolution during cooling depends critically on the cooling rates. • Heat capacities have been determined using calorimetric data. [ABSTRACT FROM AUTHOR]

New mixed-cation fluorides KNa 2 HfF 7 (Pmn 2 1 , a = 8.213(2) Å, b = 6.126(2) Å, c = 5.979(2) Å, Z = 2) and KNa 2 (Hf,Zr)F 7 (refined composition KNa 2 Hf 0.44(1) Zr 0.56(1) F 7 ; Pmn 2 1 , a = 8.2210(8) Å, b = 6.1288(6) Å, c = 5.979(1) Å, Z = 2) together with isostructural KNa 2 ZrF 7 (Pmn 2 1 , a = 8.221(2) Å, b = 6.118(2) Å, c = 5.994(2) Å, Z = 2) have been synthesised in aqueous solutions and structurally characterised at room temperature by powder and single-crystal X-ray diffraction. The solid-solid phase transformations have been revealed during the differential scanning calorimetry experiments and further confirmed by temperature-dependent X-ray powder diffraction. It has been found that mixed-cation phases KNa 2 ZrF 7 , KNa 2 HfF 7 and KNa 2 (Hf,Zr)F 7 undergo irreversible phase transformations, which can be explained by their decomposition over 673 K. XPS analysis confirmed the presence of exclusively terminated fluorines around the transition metals and the absence of oxygen impurities in the crystal structures of compounds. Crystal structure and thermal behaviour of KNa 2 HfF 7 – a typical representative of the mixed-cation A 3 M F 7 compounds (A = Na, K; M = Zr, Hf, Hf/Zr) that undergo the irreversible phase transformations due to the decomposition over 673 K. [Display omitted] • New mixed-cation fluorides KNa 2 HfF 7 and KNa 2 (Hf,Zr)F 7 have been synthesised. • KNa 2 HfF 7 and KNa 2 (Hf,Zr)F 7 are found to be isostructural to KNa 2 ZrF 7. • KNa 2 HfF 7 is characterised by the disordered position of some fluorine atoms. • KNa 2 ZrF 7 , KNa 2 HfF 7 , KNa 2 (Hf,Zr)F 7 undergo the irreversible phase transformations. • XPS analysis confirmed the presence of terminally bonded fluorines around Zr and Hf. [ABSTRACT FROM AUTHOR]

Herein, a new hybrid, [1,3-bis(1-methylimidazolium)propane][Pb 2 I 6 ] (1), was synthesized and thoroughly characterized using microanalysis, thermogravimetric analysis (TG), differential scanning calorimetry (DSC), and powdered X-ray diffraction (PXRD) techniques. The crystal structure of 1 reveals one-dimensional face-sharing PbI 6 octahedral chains composed of Pb2+ and I− ions, with the disordered 1,3-bis(1-methylimidazolium)propane dications positioned between these inorganic chains. Remarkably, 1 exhibits high dielectric permittivity (∼200) across a wide temperature range of 123–423 K. Moreover, it demonstrates a relaxation-induced dielectric pulsing effect-like, characterized by a broad and temperature-independent dielectric anomaly peak around 263 K in ε'−T plots. The mechanisms responsible for the high dielectric permittivity and the origin of the relaxation-induced dielectric pulsing effect-like are further discussed through a comprehensive analysis of the variable-temperature crystal structure. A hybrid crystal containing one-dimensional face-sharing PbI 6 octahedral chains exhibits high dielectric permittivity across a wide temperature range of 123–423 K and a dielectric pulsing effect-like. [Display omitted] • Iodoplumbate hybrid contains face-sharing PbI 6 octahedral chains. • Iodoplumbate hybrid features high dielectric permittivity. • Iodoplumbate hybrid exhibits relaxation-induced dielectric pulsing effect-like. [ABSTRACT FROM AUTHOR]

The SO 4 tetrahedral group exhibits a low degree of polarization anisotropy, leading to a minimal level of birefringence of sulfates. Our report introduces a novel sulfate compound, RbY(SO 4) 2 ·4H 2 O, which exhibits exceptional birefringence in deep ultraviolet sulfates. This crystal possesses dimensions of 6 mm × 4 mm × 1 mm and was synthesized using a straightforward technique involving the evaporation of an aqueous solution. The structure of this substance is characterized by a unique arrangement of SO 4 tetrahedra YO 9 polyhedra, and H 2 O molecules. Each SO 4 moiety contribution two oxygen atoms to share edges with a neighboring YO 9 polyhedron, resulting in significant deformation of these groups. The unique arrangement of edge-sharing arrangement in RbY(SO 4) 2 ·4H 2 O results in a birefringence of about 0.045@546 nm. This sets a new record for sulfates in the deep ultraviolet range that have similar non-π-conjugated anionic groups. We elucidate UV–Vis–NIR diffuse-reflection, IR spectra, transmission spectra, and conduct theoretical calculations. These fascinating discoveries will improve our understanding of sulfates and provide valuable insights for studying deep-UV sulfates with strong birefringence. A new UV-transparent sulfate RbY(SO 4) 2 ·4H 2 O was synthesized by introducing alkaline earth metals into a non-Π-conjugated sulfate system. It exhibits a large birefringence and has a short cut-off edge. [Display omitted] • Synthesize a non-π conjugated large birefringent crystal RbY(SO 4) 2 ·4H 2 O (0s.045@546nm). • The edge sharing pattern of the sulfate group with the adjacent YO9 polyhedron leads to an increase in birefringence. • Provides useful insights into deep ultraviolet sulfates with large birefringence. [ABSTRACT FROM AUTHOR]

Rich in ternary intermetallics, La–Ni–Al system surprises again with the discovery of a new series of intergrowth compounds. Crystal structures of La 4 Ni 6+x Al 3-x (x = 0.3) and La 5 Ni 8+x Al 4-x (x = 0.34) were established from single-crystal diffraction data. Crystallizing within monoclinic space group C 2/ m with Z = 2, very close a and b cell dimensions and similar sets of atomic positions, new compounds represent their own structure types. The crystal structure of LaNi 2 Al was determined from powder X-ray data – it adopts a SrCu 2 Ga-type structure, space group R 3 ‾ m , Z = 3. Combinations of the fragments of LaNi 2 Al and La 2 Ni 2 Al structures generate a new homologous series of intergrowth structures – La 2 Ni 2 Al· n (LaNi 2 Al) (n = 0 ÷ 3, ∞), with La 2 Ni 2 Al and LaNi 2 Al being the parent structures for n = 0 and n = ∞, respectively. The series is built by successive addition of one "LaNi 2 Al" block to the preceding member beginning with the La 2 Ni 2 Al compound as the first one. Coordination environment of each atom sort in the intergrowth structures is essentially identical to that in the parent compounds. Electronic structure calculations predict all compounds to be metallic and show a pattern of multi-center bonding between constituent atoms. Energies of formation of the members of the series are discussed based on the DFT calculations. [Display omitted] • Four ternary intermetallics in the La–Ni–Al system were synthesized. • La 3 Ni 4 Al 2 , La 4 Ni 6 Al 3 , and La 5 Ni 8 Al 4 form a homologous family m(La 2 Ni 2 Al)·n(LaNi 2 Al). • La 2 Ni 2 Al (n = 0) and LaNi 2 Al (n = ∞) represent the parent compounds. • Atomic environment in the series is identical to those in the parent compounds. • DFT calculations show the compounds to be metallic with multi-center bonding. [ABSTRACT FROM AUTHOR]

Despite the current surge in the production of metal-organic frameworks (MOFs) by crystal engineering, more structurally diverse MOFs must be developed and prepared for the study of their application properties and structural stability. Herein, one novel two-dimensional MOF, [Sr(μ 5 -p -FPhHIDC)(H 2 O)] n (1) was solvothermally constructed and structurally characterized by adopting an organic linker, 2-(4-fluorophenyl)-1H-imidazole-4,5-dicarboxylic acid (p -FPhH 3 IDC), in which the [SrO 9 ] tetrakaidecahedrons were joined by the organic linkers to constitute a beautiful grid structure. The remarkable fluorescence characteristics and proton transfer are due to the strong coordination between the organic ligands and the central metal ions in the framework of 1 , as well as the carboxylic acid and coordination water molecules carried on the framework. Extensive tests demonstrated that, at relative humidity of 75–98 %, this MOF displayed a specific proton conductivity (10−7-10−5 S/cm) and significant room-temperature solid-state fluorescence (λ em = 406 nm). Proton conduction and luminescence mechanisms were also conjectured. This study is a helpful resource for creating MOF materials with a range of application-specific properties. Two-in-one: Proton-conductive and luminescence properties of one strontium(II)-organic framework bearing imidazole dicarboxylate One thermal-stable substituted imidazole dicarboxylate-based Sr(II) MOF was prepared and structurally characterized. Its proton-conducting and luminescence properties were examined as well. [Display omitted] • One 2D Sr(II) MOF was synthesized. • 2-Position substituted imidazole dicarboxylate. • The MOF was characterized by single-crystal X-ray diffraction. • Its proton-conductive and luminescence properties were investigated. [ABSTRACT FROM AUTHOR]

To ameliorate the potential of a promising solar cell material BaSi 2, the effects of substituting Ba with Ca atoms on the crystal structure and band gap E g of BaSi 2 , were investigated both experimentally and computationally. The solid-solution limit of the Ca atoms in BaSi 2 was approximately 2.3 at.%. Single-crystal X-ray diffraction analysis of Ba 1− x Ca x Si 2 (0.025 ≤ x ≤ 0.072) revealed that the unit cell volume decreases with Ca content x , and the Ba atoms at the A1 crystallographic site are preferentially substituted by Ca atoms. Diffuse reflectance measurements indicated that E g decreases with x (1.24 eV at x = 0 and 1.17 eV at x = 0.07). The density functional theory calculations demonstrate that the experimentally observed decrease in E g by Ca substitution can be explained qualitatively by the combination of the substitution of Ca atoms in the unit cell volume of BaSi 2 and the volume reduction. Lattice parameters normalized with respect to those of BaSi 2 and band gaps of Ba 1− x Ca x Si 2 as functions of Ca content x [Display omitted] • Solid solution limit of Ca atoms in BaSi 2 is approximately 2.3 at.%. • Lattice parameters decrease with Ca content. • Ba atoms at the A1 crystallographic site are preferentially substituted by Ca atoms. • Band gap decreases with Ca content. • Volume reduction due to Ca substitution is a main reason for decrease of band gap. [ABSTRACT FROM AUTHOR]

A new heterometallic complex {[CoSr(2,3-pdc) 2 (H 2 O) 5 ]3H 2 O} n ( 1 ), where 2,3-H 2 pdc stands for 2,3-pyridinedicarboxylic acid, has been synthesized and investigated by single crystal X-Ray diffractometry, IR spectroscopy and thermal analysis. The compound is self-organized in a polymeric structure forming a 2D framework. The 2,3-pyridinedicarboxylic acid is fully deprotonated performing several types of coordination: monodentate, bridging chelating, bidentate bridging. Thermal decomposition of the heterometallic 2,3-pyridinedicarboxylate 1 leads to the formation of a perovskite type oxide of brownmillerite series, 2 , with 20.8 % yield. Magnetic studies of 1 show the paramagnetic behavior of Co(II) ions with a significant influence of a ground state zero-field splitting at low temperatures. Variable field and temperature magnetic studies of the oxide product 2 (obtained by the controlled heating of 1 ) indicate the presence of the Sr 6 Co 5 O 15 , detected by the diffraction method. Also, trace amounts of SrCoO 2.75 and SrCoO 2.5 were revealed by magnetic and DSC methods, respectively. Synthesis of new heterometallic Co–Sr −2,3-Pyridinedicarboxylate complex and its related perovskite oxide. [Display omitted] • A new heterometallic {[CoSr(2,3-pdc) 2 (H 2 O) 5 ]3H 2 O} n complex has been synthetized. • The heterometallic complex was used as single-source for obtaining Sr 6 Co 5 O 15 perovskite. • The XRD and DSC results confirm the formation of hexagonal perovskite-related Sr 6 Co 5 O 15 compound. • The magnetic studies of complex indicate paramagnetic behavior with the considerable influence of a crystal-field splitting. [ABSTRACT FROM AUTHOR]

In this study, single crystals of two new quaternary chalcogenides, CsY 2 M 3 Se 5 (M = Cu and Ag), have been prepared by the molten-flux method at 1273 K. Single-crystal X-ray diffraction studies established that both the compounds crystallize in the space group Cmcm of the orthorhombic crystal system and are isostructural. The title compounds, CsY 2 M 3 Se 5 adopt the RbSm 2 Ag 3 Se 5 structure type. The CsY 2 M 3 Se 5 structure has seven crystallographically independent atomic sites (one Cs, one Y, two Cu/Ag, and three Se sites) that are fully occupied to form a three-dimensional (3D) tunnel-type structure. These valence-precise compounds are built up of the anionic framework of 3 ∞ [Y 2 M 3 Se 5 ]1−, where the Cs+ cations are present in the tunnels as space fillers. The Y atoms in both structures are octahedrally coordinated with six Se atoms, while Cu/Ag (M) atoms form a tetrahedral geometry. These distorted YSe 6 octahedra share corners and edges with neighboring M Se 4 tetrahedra to form 3D anionic networks. An optical absorption study shows the semiconducting nature of the CsY 2 Ag 3 Se 5 in agreement with DFT studies of the title structures. The electronic structure and the theoretical thermoelectric properties of the CsY 2 Cu 3 Se 5 and CsY 2 Ag 3 Se 5 have also been calculated using the DFT method. Single crystals of two new quaternary chalcogenides, CsY 2 M 3 Se 5 (M = Cu and Ag), have been synthesized using the molten-flux method. The optical absorption and DFT studies show the semiconducting nature of the CsY 2 Ag 3 Se 5 compound. [Display omitted] • Single crystals of two new quaternary selenides, CsY 2 M 3 Se 5 (M = Cu and Ag), are synthesized via the reactive-flux method. • Both the compounds are isostructural and form a 3D tunnel-type structure where YSe 6 and M Se 4 act as building blocks. • The Cs atoms reside in the tunnels and form a distorted bicapped trigonal prismatic geometry. • The optical absorption dataset collected for the powdered CsY 2 Ag 3 Se 5 crystals shows a direct bandgap of 1.7(1) eV. • The DFT studies have also confirmed that the CsY 2 M 3 Se 5 are semiconductors. [ABSTRACT FROM AUTHOR]

This study focuses on the synthesis and characterization of the novel Ni(II)(L-threoninato)2(H2O)2 crystal, a bivalent transition metal complex based on Ni(II) ions, based on crystalline structure and thermal properties. Through crystallographic analysis, we reveal that Ni(II)(L-threoninato)2(H2O)2 complex adopts an orthorhombic system with the C2221 space group. To gain insights into its thermal behavior, thermogravimetric analysis, and differential scanning calorimetry techniques were employed to estimate kinetic parameters related to its thermal degradation. Model-free analysis, employing Friedman, Ozawa-Flynn-Wall, and Kissinger-Akahira-Sunose methods, along with model-based analysis, were utilized to evaluate the activation energy and the logarithm of the pre-exponential factor. Furthermore, we elucidated the complex's crystalline structure thermal behavior using Powder X-ray Diffraction measurements as a function of temperature, at air and under vacuum. No phase transitions were detected at low temperatures only at high temperatures due to loss of water molecules. The measurements showed the crystal goes to a partially crystalline anhydrous phase with a certain long-range order in the [001] direction. Through Rietveld refinement the behavior of the lattice parameters and thermal expansion coefficients were obtained. This comprehensive study provides valuable knowledge about the Ni(II)(L-threoninato)2(H2O)2 crystals and lays the foundation for further exploration of similar complexes. 3D-plot of the thermal decomposition showing the TGA curve and the IR spectra of the released gases. XRD pattern showing the crystal keeps a long-range order in the [001] direction during the water loss partial amorphization. Thermal behavior of lattice parameters obtained by Rietveld refinement. [Display omitted] • Synthesis and crystal structure of the novel Ni(II)(L-threoninato) 2 (H 2 O) 2 crystal. • Thermal behavior of the Ni(II)(L-threoninato) 2 (H 2 O) 2 crystal by means of PXRD. • Thermal behavior and kinetic studies using TGA and DSC analysis. • Thermal expansion coefficients in air atmosphere and also under vacuum. • Partially crystalline anhydrous phase with long-range order in [001] direction. [ABSTRACT FROM AUTHOR]

The crystal structure of CuCrSe 2 in the temperature range 25 - 1000 °C was studied by synchrotron X-ray diffraction. It was found that heating leads to the decomposition of stoichiometric CuCrSe 2 into two phases of composition CuCr 2 Se 4 and Cu 1+x CrSe 2 with increased Cu content. It was found that copper enrichment of CuCrSe 2 during heating occurs up to the temperature of 800 °C and the limiting composition is close to the compound Cu 4 Cr 3 Se 6. It was found that heating equalizes the copper distribution at the α- and β-tetrahedrally coordinated chalcogen positions, but full equality of their occupancy at temperatures up to 1000 °C was not achieved. The low temperature limit of CuCr 2 Se 4 excretion was established to be approximately 300 °C and the decomposition temperature of CuCr 2 Se 4 to be approximately 1050 °C. Fragments of the crystal structure CuCrSe 2 for P-3m1 (left panel), R-3m (central panel) and R3m (right panel) space group. [Display omitted] • The synthesis of CuCrSe 2 has been performed. • A study of the crystal structure during in-situ heating was performed. • The region of phase instability has been established. • The defect type of CuCrSe 2 is defined. • A fragment of the phase diagram is proposed. [ABSTRACT FROM AUTHOR]

The phase relationship in the SnTe–Bi 2 Te 3 pseudo-binary system has been reinvestigated experimentally by means of powder X-ray diffraction (XRD), differential thermal analysis (DTA), and scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX) techniques to obtain a better description of the phase diagram. The new version of the phase diagram differs from previous versions. The formation of a total of 5 tetradymite-type ternary compounds has been experimentally confirmed, including 4 compounds mentioned in the literature and, for the first time, a new compound Sn 3 Bi 2 Te 6. The newly revealed phase was determined to be a rhombohedral structure (space group R -3 m , No. 164, lattice parameters: а = b = 4.40935 Å, c = 63.8370 Å in hexagonal representation) based on the powder XRD data and melts with solid-phase reaction, while other re-confirmed ternary compounds have peritectic melting character. Furthermore, the solid solubility of starting binary compounds SnTe and Bi 2 Te 3 is established to be ∼12 and 9 mol % at 450 °C, respectively. A eutectic temperature of 575 °C was observed at a composition of ∼85 mol% Bi 2 Te 3. The current updated version of the phase diagram can provide the essential information for alloying strategies and guide the designing of the Sn–Bi–Te-based high-performance functional materials. [Display omitted] • An improved version of phase diagram of the SnTe--Bi 2 Te 3 pseudo-binary system was proposed. • The formation of new tetradymite-type layered ternary compound Sn 3 Bi 2 Te 6 was confirmed experimentally for the first time along with already known 4 ternary intermediate compounds. • The complete description of crystal structure of the newly found compound was identified by Rietveld method. [ABSTRACT FROM AUTHOR]

To search for more high-performance crystalline proton conducting materials and to accelerate the related research progress, in this paper, a one-dimensional coordination polymer (CP), [Co(BBOT) 2 (H 2 O) 3 ·2H 2 O] n (1) (H 2 BBOT = N-benzoyl-N′-(4-benzoxy)thiourea) was firstly prepared by solvent volatilization approach. Subsequently, the thermal, H 2 O and chemical stabilities of the CP were tested and its high structural stability was confirmed. Furthermore, in 1 , a stable solid three-dimensional framework can be constructed by intermolecular H-bonds and stacking interactions between phenyl units. Then, utilizing the AC impedance determination, the dependence of the proton conductivity of this CP on temperature and humidity in the water vapor environment was explored and the positive correlation was verified. Excitingly, the optimized proton conductivity of this compound under specific test conditions (100 °C/98 % relative humidity) can be as high as 10−4 S/cm, being in the forefront of similar crystalline solid materials. Finally, according to the value of activation energy and the characteristics of crystal structure, we speculate on the proton conduction mechanism. Proton conductivity of a CP under variable humidity and temperatures was explored. Its highest proton conductivity can attain up to 10−4 S/cm, and its proton-conduction mechanism was speculated. [Display omitted] • One carboxylate-based Co(II) coordination polymer was prepared. • Its structure was characterized by single-crystal X-ray diffraction. • Its water-assisted proton conduction was explored. • The proton-conducting mechanism was speculated. [ABSTRACT FROM AUTHOR]

A novel bismuth-based zero-dimensional organic-inorganic hybrid material (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 was synthesized by a hydrothermal method. The crystal structure, intermolecular interactions, chemical groups, chemical bond characterization, optical and thermal stability of the sample were systematically investigated by single crystal X-ray diffraction, powder X-ray diffraction, Hirshfeld surface analysis, field scanning electron microscopy, Fourier transform infrared spectrometer, Raman spectra, thermogravimetric analysis, and Ultraviolet–visible diffuse reflectance spectra. The results indicated that the (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 crystal displayed a triclinic crystal system with a P-1 space group at room temperature with a = 8.5290(4) Å, b = 14.2484(10) Å, c = 18.9386(10) Å, α = 94.418(5) °, β = 102.260(4) °, γ = 106.595(5) °, V = 2131.9(2) Å3, Z = 2, R 1 = 0.0936, w R 2 = 0.1536. The compound displayed typical zero-dimensional consisting of two benzylamine organic [C 6 H 5 CH 2 NH 3 ]+ cations, three dimethylamine organic [CH 3 CH 3 NH 2 ]+ cations and a corner-sharing dimer unit [Bi 2 Br 11 ]5–. Infrared and Raman vibrational study indicates the presence of [CH 3 CH 3 NH 2 ]+. The 2D fingerprint plot of Hirshfeld surface analysis shows that H⋯Br/Br⋯H (56.8 %) and H⋯H (31.4 %) are major contributions to the intermolecular contact of (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11. The sample presented relatively perfect thermal stability up to 240 °C and a wide band gap of about 2.75 eV. It provides some reference value for exploring organic-inorganic hybrid materials with low toxicity and high thermal stability. The physical image of (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 single crystal prepared by hydrothermal method and its crystal structure, Hirshfeld surface, thermal stability and optics analyses. [Display omitted] • Structure and morphology of (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 were studied. • Synthesis mechanism of (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 single crystal was studied. • Optical property and stability of (C 6 H 5 CH 2 NH 3) 2 (CH 3 CH 3 NH 2) 3 Bi 2 Br 11 were investigated. [ABSTRACT FROM AUTHOR]

A detailed study of the Re–S–Br system in the temperature range (650 – 1150 °C) of the formation of hexarhenium thiobromides with the general formula Re 6 S 4+n Br 10–2n , has revealed the features of phase formation and the factors influencing the production of pure phases. It was found that in reactions with a given stoichiometry 6Re + nS, a mixture of products is usually formed, namely a compound based on a cluster core with the targeted Re/S stoichiometry Re 6 S n , an admixture compound with Re 6 S n+1 core, and a soluble by-product (3–5% of the total mass), consisting of rhenium bromides and thiobromides. It was found that the composition of the by-product (Re/S ratio) has a significant effect on the fraction of the admixture compound with higher sulfur content. The slow cooling rate of the reaction mixture, leads to the obtaining of a pure target compound with the {Re 6 S n Br 8–n } cluster core. In the course of the study of the Re–S–Br system, the crystal structure of Re 6 S 7 Br 4 was solved (space group R –3 c , a = 9.5804(2) Å, c = 31.0676(10) Å, V = 2469.48(13) Å3, Z = 6). The study of the thermal behavior showed that the stability of Re 6 S 4+n Br 10–2n increases with increasing sulfur content in the cluster core. XPRD data showed that the decomposition of octahedral cluster thiobromides leads to the formation of sulfur-rich phases. This process is accompanied by the release of elemental bromine, metallic rhenium and the formation of soluble by-products with the overall composition "Re 2 SBr x ". A detailed study of the Re–S–Br system revealed the peculiarities of phase formation in high-temperature reactions and led to the development of methods for obtaining various hexarhenium thiobromides in pure form. In particular, the compound Re 6 S 7 Br 4 was synthesized and structurally characterized. [Display omitted] In this work, we described a detailed study of the Re-S-Br system that revealed the peculiarities of phase formation and the factors influencing the obtaining of pure phases. We also studied the soluble by-products of syntheses and found that it consists of rhenium bromides and thiobromides. It worth nothing that that their composition (Re/S ratio) depends on the cooling rate of the synthesis, which affects the purity of the obtained target product. [ABSTRACT FROM AUTHOR]

In this study, polycrystalline intermetallic compounds Ce 3-x Pd 20+x Si 6 (x = 0; 0.5; 1) as well as La-based analogues La 3-x Pd 20+x Si 6 (x = 0; 1) are synthesized. At the same time, R 2 Pd 21 Si 6 (R Ce, La) are new rare earth compounds presented here. An analysis of the crystal structure shows that the increase in x leads to partial (x = 0.5) or complete (x = 1) replacement of Ce/La ions by Pd in one of the two Wyckoff positions, namely, in position 4 a. Ab initio DFT calculations demonstrate good agreement between the determined lattice parameters and those found experimentally for both Ce 3-x Pd 20+x Si 6 (x = 0; 0.5; 1) and La 3-x Pd 20+x Si 6 (x = 0; 1). A comparative analysis of resistivity and specific heat of Ce 3-x Pd 20+x Si 6 with x = 0; 0.5; 1 makes it possible to associate the Ce ions in the 8 c position with Kondo behaviour in all three compositions, which manifests itself in an increase in resistivity with cooling, as well as in a broad peak of the magnetic contribution of specific heat. The Kondo temperature T K ≈ 25 K obtained from the analysis of the temperature dependences of the heat capacity turns out to be the same for all Ce compounds. The appearance of cerium ions in the position 4 a in compositions with х = 0 and х = 0.5 leads to an additional contribution to the specific heat, the value of which increases with decreasing temperature, as well as, to the formation of a coherent Kondo-lattice state with a maximum of the resistivity at T coh ≈ 15 K, followed by the subsequent onset of negative magnetoresistance regime below T inv ≈ 7 K. Apparently, this behaviour is associated with the appearance of spin and orbital correlations proceeding the quadrupole and antiferromagnetic transitions occurring at lower temperatures. Magnetization measurements show more localized character of magnetic moments of Ce ions at T = 2 K in Ce 3 Pd 20 Si 6 as compared to the Ce 2 Pd 21 Si 6. The orthogonal projection of the Ce 3-x Pd 20+x Si 6 (x = 0; 1) structural unit cell and coordination polyhedra of the atoms in 4 a (a) and 8 c (b) crystallographic sites, space group Fm -3 m. [Display omitted] • Novel ternary Ce-based and La-based intermetallides. • Primary study of Ce 2 Pd 21 Si 6 crystal structure. • Replacement of Ce with Pd in one crystallographic position. • Magnetic, transport and specific heat study of new intermetallides. • Role of Ce ions in 4a Wyckoff position in Kondo behaviour of Ce 3-x Pd 20+x Si 6. [ABSTRACT FROM AUTHOR]

Single crystals of the novel arsenate, Na 3 Al 3 (AsO 4) 4 have been isolated and their structure has been determined by X-ray diffraction experiment. Na 3 Al 3 (AsO 4) 4 crystallizes in the monoclinic space group C2/c with a = 19.837(1) Å; b = 6.448(3) Å; c = 10.437(6) Å, β = 91.986 (3)° and Z = 2. The structural model was confirmed by both bond valence sum (BVS), charge distribution (CHARDI) validation tools and density functional theory (DFT) method. The empirical activation energy for sodium migration channels within the crystal structure was estimated by the bond valence site energy landscape (BVSE) map method. With an energy barrier of 0.409 eV, the crystal structure features 3D networks of pathways suitable for Na+ ion migration. [Display omitted] • A novel arsenate Na 3 Al 3 (AsO 4) 4 was grown by solid state reaction. • The crystal structure was determined by single-crystal X-ray diffraction. • Preferred migration pathways of Na + are simulated by means of Bond valence site energy (BVSE) model. [ABSTRACT FROM AUTHOR]

We present the high-pressure/high-temperature synthesis (10 GPa, 1073 K) of the second known tellurium borate Te 2 B 2 O 7. It crystallizes in a unique crystal structure with the lattice parameters a = 1876.54(5) pm, b = 1170.11(3) pm, c = 440.43(1) pm, V = 0.967(1) nm3, and eight formula units (Z = 8) per unit cell in the orthorhombic non-centrosymmetric space group Pna 2 1 (no. 33). The structure contains only corner connected tetrahedral [BO 4 ]5– and bisphenoidal [TeO 4 ]4–units. The structure is discussed in detail and theoretical calculations including a visualization of the electron localization function have been carried out. The synthesis and the crystal structure of Te 2 B 2 O 7 are presented and theoretical calculations on DFT level were performed. [Display omitted] • Te 2 B 2 O 7 is the 2nd tellurium borate and exhibits a unique crystal structure. • Te 2 B 2 O 7 was synthesized in a multianvil device at 10 GPa and 1073 K. • Te 2 B 2 O 7 crystallizes in the orthorhombic non-centrosymmetric space group Pna 2 1. [ABSTRACT FROM AUTHOR]

This paper reports the synthesis, structure, BFDH crystal morphology, Raman and Infrared spectroscopic studies of three novel metal orthophosphate salts MII(Ga 0.5 Sb 0.5)(PO 4) 2 (MII= Sr, Pb, Ba), abbreviated [Sr], [Pb], [Ba]. The structures of these phases are refined from X-ray powder diffraction data by the Rietveld method. The yavapaiite [Ba] phase is monoclinic of C2/m space group [Z=2; a= 8.106(4) Å; b= 5.178(3) Å c= 7.806(1) Å, β=94.79(4)°, V= 327(1) Å3]. Its structure consists of layers, running along the (a, b) plane, and built up of corner-connected Ga(Sb)O 6 octahedra and PO 4 3− tetrahedra. The two isotypic phases [Sr]/[Pb] of distorted yavapaiite structure crystallize in the monoclinic C2/c space group (Z=4) with parameters: a=16.455(4)/16.622(7) Å; b=5.158(1)/5.163(2) Å c= 8.005(1)/8.067(3) Å; β=115.49(1)/114.85(2)°, V= 613(1)/628(5) Å3. Their structures consist of MO 10 (M= Sr, Pb), PO 4 3− tetrahedra and Sb(Ga)O 6 octahedra. In [Pb] phase, the Pb is surrounded by eight oxygen atoms (Pb-O: 2.65-2.77 Å) and two oxygen atoms forming abnormal bond distances Pb-O(4) [3.447(3)Å]. The BFDH crystal morphology predicts hight (h k l) facets for each compound, the center-to-plane distances d hkl are slightly strong in the distorted Yavapaiite [Pb/Sr] rather than in [Ba]. The IR and Raman study is performed based on theoretical group analysis considering C s site symmetry of PO 4 3− groups in [Ba], and C i symmetry in [Pb]/[Sr] phases. The assignment and discussion of the observed bands were done by comparison with other yavapaiite materials. The UV–visible investigation reveals direct optical gap energies of values 4.16 eV for [Ba] and 4.24 eV for [Sr], indicating a semi-conducting nature of the prepared materials. Crystal structures, UV absorbance, and and Tauc Plots (F(R)hν)1/2 of versus hν of AII(Sb 0.5 Fe 0.5)(PO 4) 2 (AII = Ba, Pb, Sr) compounds. [Display omitted] • Novel A(Sb 0.5 Ga 0.5)(PO 4) 2 (A= Ba, Pb, Sr) crystal structures are determined and discussed. • The BFDH morphology of [Ba] and [Sr] are simulated from parametres and Laue symmetry of these crystals. • Theoretical analyses are made in assignment of IR and Raman bands for the three phases. • UV–visible absorptions indicate a semi-conducting nature of the synthetised materials. [ABSTRACT FROM AUTHOR]

To develop efficient and reusable catalysts for biodiesel production, quaternary heteropolyacid H 4 PVMo 2 W 9 O 40 (PVMo 2 W 9) was effectively wrapped inside rht -MOF-1 { rht -MOF-1 = [Cu 6 O(TZI) 3 (H 2 O) 6 ] 4 ⋅nH 2 O}, affording a crystalline H 4 PVMo 2 W 9 O 40 @ rht -MOF-1 (1) by one-pot hydrothermal method. The identification of the crystal structure of 1 was achieved through the utilization of X-ray crystallography. Nano-size crystals of 1 (n-1) were prepared with the assistance of surfactant Tween 20. Notably, crystal n-1 was of cube shape grown along {100} facets rather than octahedral shape for 1. When n-1 was applied as the catalyst for the esterification reactions, high conversion rates were achieved. E. g. about 97 % conversion for oleic acid to the corresponding monoalkyl esters and about 87 % for rapeseed oil to biodiesel. The catalyst was heterogeneous and recyclable 7 times without obvious attenuation. Further, the correlation between the catalytic activity and structure of n-1 was investigated in terms of the distribution of active sites, various pores in rht -MOF-1, and the accessibility of catalytic sites on the {100} facets. nano-crystal PVMo 2 W 9 @ rht -MOF-1 exhibited an efficient heterogeneous catalytic capacity for biodiesel preparation. [Display omitted] • H 4 PVMo 2 W 9 O 40 is wrapped rht -MOF-1 affording 1 by solvothermal reactions. • Nanocrystals 1 (n - 1) is prepared via the introduction of surfactant. • n - 1 with high {100} results in high catalytic activity for biodiesel production. [ABSTRACT FROM AUTHOR]