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Treating conic tetra-para-ethylacetato-calix[4]arene (1) with 2.2 equivalents of K2CO3 and 4 equivalents of 6-bromomethyl-6′-methyl-2,2′-bipyridine affords the expected fully substituted podand, mainly in its 1,3-alternate conformation (2). This tube-like bipyridyl derivative 2 was subjected to complexation studies with CoCl2·6H2O to give a blue tetra cobalt(II) complex species (3). This complex displays a unique group of 6 aromatic bipyridyl 1H-NMR resonance signals demonstrating its high symmetry, while X-ray diffraction studies showed the presence of 3 expected tetrahedral bpy(CoCl2) units and 1 original trigonal bipyramidal unit involving the adjunction of a fifth ligand assumed to be H2O that could participate in the crystal scaffold. [ABSTRACT FROM AUTHOR]

New fluorinated dibenzo-1,2,5,6-tetrathiocines 1 and 2 were synthesized by a novel condensation of 1,2-disulfenyl chlorides under the influence of elemental Cu, and structurally defined in the solid state, solution, and gas phase by single-crystal XRD, variable-temperature 19F NMR and NOESY, and DFT calculations. Crystalline 1 and 2 exhibited the C2h chair and C2 twist molecular conformations, respectively. Unlike 1 displayed only C⋯S shortened intermolecular contacts, crystal structure of 2 featured F⋯π, F⋯F, F⋯S and S⋯S contacts. In toluene solutions at 296 K, both twist and chair conformers were observed in the ∼1 : 1 and ∼7 : 1 ratios for 1 and 2, respectively. For 1, the twist ↔ chair conformer interconversion was practically temperature-independent, and for 2 revealed ΔH ∼3.5 kJ mol−1 and ΔS ∼4.4 J K−1 mol−1. With DFT, the PESs for twist–chair transformation and twist–twist racemization were analyzed and the TSs exhibiting twist–halfchair and boat conformations, respectively, were found. Several additional stationary points on the PESs, corresponding to hidden intermediates and bifurcation points and featuring twistboat and halfchair conformations were detected. In chloroform solution under sunlight, 1 underwent 1,2,5,6-tetrathiocine → 1,2,3,6-tetrathiocine isomerization whose product was characterized by XRD. [ABSTRACT FROM AUTHOR]

Nine lanthanide-organic frameworks [Ln(L)1.5(H2O)3] (1-Ce, 2-Dy, 3-Eu, 4-Gd, 5-Ho, 6-Nd, 7-Pr, 8-Sm, and 9-Tb; H2L = 4,4'-(1,2-dihydroxyethane-1,2-diyl)dibenzoic acid) have been synthesized under solvothermal conditions. Single-crystal X-ray diffraction analyses show that compounds 1-9 are isomorphic, in which each Ln atom is linked by L ligands to form a 3D framework with an unprecedented 4,4,6-connected topology. All these compounds have excellent solvent stability and can remain stable in boiling water for up to a week. Moreover, these compounds exhibit metal-dependent luminescence and magnetic properties. 3-Eu and 9-Tb exhibit relatively good fluorescence properties, 4-Gd shows ferromagnetic coupling, and the other compounds present antiferromagnetic coupling. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) emissive probes are becoming increasingly popular in biological sensing and imaging due to the advantages of non-invasiveness and deep tissue-penetrating ability. Herein, a series of complexes of trivalent lanthanide ions (Ln = Yb, Er, and Gd) with the commercially available azo dye chromophore 2R (Na2H2C2R) as ligand and featuring respectively H2O and dimethylsulfoxide (DMSO) as ancillary ligands have been prepared. Formulated as [Ln2(HC2R)2(H2O)10]·8H2O (1-3, Ln = Yb, Er, Gd) and [Ln2(HC2R)2(DMSO)10]·2DMSO (4-6, Ln = Yb, Er, Gd), their structures have been determined by singlecrystal X-ray diffraction studies. Photophysical property studies revealed NIR emissions of the DMSO complexes characteristic of Yb(III) and Er(III), effectively sensitized by the dye ligand arising mainly from the π-π* transition of the chromophore. The long-wavelength excitation of the complexes, covering the whole visible-light range and extending into the NIR region, portends the potential applications of such complexes for flexible bioimaging and sensing. [ABSTRACT FROM AUTHOR]

The influence of the metal ratio on the geometric characteristics and crystal structures of heterometallic clusters with {Re6−xMoxQ8} cores was studied. For this purpose, nine new molecular cluster complexes of the type [Re6−xMoxS8L6] (x = 2, 3 or non-integer value between 2 and 3; L = pyridine, 4-ethylpyridine or 4-tert-butylpyridine) were synthesized. The compounds were obtained by one-step replacement of the cyanide apical ligands of [Re6−xMoxS8(CN)6]5−/4− cluster complexes with the corresponding organic compounds under solvothermal conditions. The crystal structures of all the obtained compounds were investigated by single-crystal X-ray diffraction analysis. Analysis of the crystal structures showed that clusters with the same apical ligands and different x values have similar geometries and form isostructural packings, demonstrating the formation of solid solutions. [ABSTRACT FROM AUTHOR]

Single crystals of two new intermetallic phases Sm2Mn1−xGa6−yGey (x = 0.1–0.3, y = 0.6–1.0) and Sm4MnGa12−yGey (y = 3.0–3.5) were grown using a self-flux technique. According to single crystal X-ray diffraction data, Sm4MnGa12−yGey is characterised by the Y4PdGa12 structure type (a ∼ 8.65 Å; Im3¯m), while Sm2Mn1−xGa6−yGey formally adopts the K2PtCl6 structure type (a ∼ 8.71 Å; Fm3¯m). The general features of both compounds with rather similar crystal structures are represented by the alternation of empty and Mn-filled p-element octahedra, the order of which is determined by the Mn concentration. The diffraction data for Sm2Mn1−xGa6−yGey reveal a large concentration of Mn vacancies (x ∼ 0.3), which affects adjacent Ga/Ge atoms leading to their shift towards the vacancy. Both compounds demonstrate two ferromagnetic-like transitions and the presence of two interacting Mn and Sm magnetic sublattices. The Mn sublattice orders at TC1 of 143 K and 318 K, while the Sm one orders at lower temperatures at TC2 of 50 K and 280 K for Sm4MnGa8.6Ge3.4 and Sm2Mn0.74Ga5.1Ge0.9, respectively. The increase in Mn content not only increases the ordering temperatures, but also dramatically decreases the coercivity μ0HC from 230 mT to just 6.5 mT at 2 K. Despite the presence of two magnetically active sublattices in Sm2Mn0.74Ga5.1Ge0.9, the magnetic entropy change is quite low and only reaches 0.3 J kg−1 K−1 at T = 300 K and μ0H = 5 T, while the estimated relative cooling power (RCP) is about 36 J kg−1 at 5 T. [ABSTRACT FROM AUTHOR]

In the fairly modest temperature and pressure regime of 0–2 GPa and 200–295 K, 2,2,2-trifluoroethanol (TFE) exhibits a remarkable degree of polymorphism, with the observation of four ordered phases (forms 1–4) and a cubic plastic phase (form 5). The ordered phases are characterised by hydrogen-bonded chains, with the crystal structures of the three high-pressure forms (forms 2, 3 and 4) based on the same hydrogen-bonded catemeric motif. The structures and relationships between these phases were determined using a combination of high-pressure single-crystal X-ray diffraction, at ambient temperature, and a series of high-pressure neutron powder-diffraction experiments to ∼6 GPa at 295 K, 245 K and 200 K. As well as allowing the determination of the relative compressibilities of the phases, the neutron powder-diffraction studies also provided a preliminary mapping of the surprisingly rich phase diagram of TFE. [ABSTRACT FROM AUTHOR]

A series of cationic Au(I)-BIAN/MIAN complexes, namely [(PPh3)Au(L)]OTf, where L = dpp-bian (1), dpp-mian (2), 2-Me-Ph-bian (3) and 4-Me-Ph-bian (4), has been prepared. All complexes were characterized by analytical and spectroscopic methods and their crystal structures were determined by X-ray diffraction analysis. In all structures, an asymmetric mode of coordination of the di- or monoimine ligand (one shortened Au–N bond and the second elongated Au–N(O) bond) was found, which is a consequence of the so-called antichelate effect. The analysis of the bonding in the coordination environment of gold(I) and the coordination geometry in cations 1–4 was carried out using DFT calculations. The cyclic voltammograms of 1–4 in dichloromethane featured a series of ligand-centered redox processes in the cathodic region. Preliminary bioactivity tests for complexes 1–4 and respective imine ligands have been performed. [ABSTRACT FROM AUTHOR]

Using single crystal XRD, it was proved that the cyclocondensation of 3,4-diaminofurazan with diethyl-2-oxosuccinate gives two products belonging to different heterocyclic systems, being structural isomers -derivatives of furazano[3,4-b]pyrazin-6-one (2) and furazano[3,4-b][1,4]diazepin-7-one (6). The simultaneous formation of compounds 2 and 6 in this reaction provokes also the generation of a third solid product, an unusual co-crystal (2)0.40(6)0.60. This is a rare example of co-crystallization of two isomers, the molecules of which occupy the same position in the crystal structure, despite the differences of the heterocyclic systems. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of a (VO)2+ representative in the bradleyite family of compounds is reported. The new trisodium vanadyl phosphate carbonate was investigated using scanning electron microscopy, microprobe analysis, low temperature X-ray diffraction, and theoretical calculations of possible pathways of Na migration through the framework. Its crystal structure is assembled from strongly distorted VO6 octahedra, PO4 tetrahedra, and triangular CO3 groups linked into one-periodic ribbons parallel to the b axis of a monoclinic unit cell. Na atoms occupy positions between these ribbons and connect them into a framework. It is shown that the formal exchange of Fe2+ or Mn2+ for (VO)2+ ions leads to the bonshtedtite and sidorenkite crystal structure transformation from layered to chain ones. The character of the Na atom distribution in the structure allows considering Na3(VO)(PO4)(CO3) as a potential electrochemically active material. [ABSTRACT FROM AUTHOR]

YbFe2O4-type layered oxides have attracted tremendous interest because the unique crystal comprises two distinct geometrically frustrated triangular cation-sublattices. Herein, a series of YbFe2O4-type materials In2Zn3−xCoxGeO8 (0 ≤ x ≤ 3) were rationally designed and experimentally synthesized for the first time. The crystal structures of In2Zn3−xCoxGeO8 were investigated comprehensively by Rietveld refinements against high-resolution monochromatic Cu Kα1 XRD data. Zn2+, Co2+, and Ge4+ cations are distributed randomly on the [MO]2 bilayer and possess a trigonal bipyramid (TBP) coordination geometry. Because Co2+ has an unpaired electron in the dz2 orbital and a larger electronegativity than Zn2+, Co2+-to-Zn2+ equivalent substitution in In2Zn3−xCoxGeO8 results in more compact MO5-TBPs, which is the origin of anisotropic lattice expansion and contraction along the a and c axes, respectively. The Co2+ moments in the [MO]2 bilayer are strongly AFM coupled and geometrically frustrated, therefore resulting in a spin-glass magnetic transition at around Tg = 20 K for In2ZnCo2GeO8, while a long-range AFM ordering is established for In2Co3GeO8 with a Néel temperature of 53 K, attributed to the significantly enhanced AFM interactions and increased In3+/Co2+ anti-site disordering, as compared to those in In2ZnCo2GeO8. [ABSTRACT FROM AUTHOR]

Luminescent materials used in solid-state lighting usually face the challenge of the adjustment of luminescence properties. The coordinated luminescence of two activators in luminescent materials is a good method. Herein, CaAl2Si2O8:Dy3+, CaAl2Si2O8:Eu3+, and CaAl2Si2O8:Dy3+, Eu3+ with a pure phase (CaAl2Si2O8) were synthesized in air. The X-ray diffraction patterns of the samples were measured and their crystal structures were elucidated. Under excitation at 350 nm, the yellow emission of CaAl2Si2O8:Dy3+ in the spectral range of 525–800 nm was observed due to the 4F9/2 → 6H15/2, 6H13/2, 6H11/2, and 6H9/2 transitions of Dy3+ ions. CaAl2Si2O8:Eu3+ showed red emission in the range of 550–720 nm because of the transitions 5D0 → 7F1, 7F2, 7F3, and 7F4 of Eu3+ ions when it was excited by 394 nm light. A tunable color emission of CaAl2Si2O8:Dy3+, Eu3+ from yellow to red was found when the ratio between Dy3+ and Eu3+ ions was changed. We investigated the concentration-dependent spectra and ensured the optimal Dy3+ and Eu3+ concentrations in host CaAl2Si2O8. The spectra of the samples manifested the energy transfer from Dy3+ to Eu3+ ions. The energy-level diagrams of Dy3+ and Eu3+ ions were used to analyze the luminous mechanism of the samples. The research results are beneficial to the development of other Dy3+ and Eu3+ co-doped luminescence materials. [ABSTRACT FROM AUTHOR]

Weakly coordinating anions (WCAs) facilitate the stabilization and isolation of highly reactive and almost "naked" cations. Alkoxyaluminate-based WCAs such as [Al(OC(CF3)3)4]− ([pf]−) are widely used due to their synthetic accessibility and their high stability. However, small cations are still able to coordinate the oxygen atoms of the [pf]− anion or even to abstract an alkoxy ligand. The novel WCA [Al(OC10F15)4]− ([pfAd]−; OC10F15 = perfluoro-1-adamantoxy) is characterized by a very rigid core framework, thus indicating a higher stability towards fluoride-ion abstraction (DFT calculations) and providing hope to generate less disordered crystal structures. The [pfAd]− anion was generated by the reaction of the highly acidic alcohol perfluoro-1-adamantanol C10F15OH with LiAlH4 in o-DFB. Li[pfAd] could not be synthesized free of impurities (and still contains unreacted alcohol). Yet, starting from contaminated Li[pfAd], the very useful pure salts Ag[pfAd], [Ph3C][pfAd] and [H(OEt2)2][pfAd] could be synthesized. The salts were characterized by NMR spectroscopy, single-crystal X-ray diffraction and IR spectroscopy. Additionally, [NO][pfAd] could be synthesized containing alcohol impurities but nonetheless enabled the synthesis of the salt P9+[pfAd]−. The synthesis of Tl[pfAd] in a mixture of H2O/acetone/o-DFB demonstrated the water stability of the [pfAd]− anion. [ABSTRACT FROM AUTHOR]

Mononuclear oxovanadium(V) complexes [V(O)XL (1: X = Ot-Bu, 2: X = Cl)] [H2L: 2,2′-methylene bis(4,6-di-tert-butylphenol)(4′-tert-butyl-6′-(1-adamantyl)phenol)] directed towards asymmetric catalysis have been synthesised as racemic compounds using an unsymmetric and achiral phenolic bidentate ligand (H2L), and NMR and UV-vis absorption spectroscopies, single-crystal X-ray diffraction, and IR spectroscopy revealed their racemic chiral-at-vanadium structures in solution and in the crystal. In addition, theoretical calculations revealed that the HOMO–LUMO energy gap is smaller for unsymmetric ligands, which promotes d-orbital splitting of the metal centre. [ABSTRACT FROM AUTHOR]

A series of new heteroleptic copper(I) complexes [Cu(N^N)(P^P)][BF4] (1–6), where N^N is a pyrazole-substituted 2,2′-bipyridine (5-(1H-pyrazol-4-yl)-2,2′-bipyridine (5-pzbpy, L1), 4,4′-di(1H-pyrazol-4-yl)-2,2′-bipyridine (4,4′-pz2bpy, L2), 5,5′-di(1H-pyrazol-4-yl)-2,2′-bipyridine (5,5′-pz2bpy, L3), and 3,8-di(1H-pyrazol-4-yl)-1,10-phenanthroline (3,8-pz2phen, L4)) and P^P is either oxybis(2,1-phenylene)bis(diphenylphosphane) (POP) or 1,3-bis(diphenylphosphanyl)propane (dppp), were successfully prepared and investigated. The crystal structures of 1, 2, 3 and 6 were determined by single X-ray diffraction. The novel copper(I) complexes 1, 2 and 3 show turn-on emission sensing for halogen ions. The fluorescence enhancement of the copper(I) complexes increases in the order of F− < I− < Br− < Cl−, and the differences in fluorescence intensity could be easily distinguished with the naked eye under UV light illumination. The 1H NMR titration indicated that the interaction involves hydrogen-bond formation between the halide (Cl−, Br− and I−) and the acidic H of the pyrazole group, with N–H deprotonation occurring at increasing F− concentrations. The result was further confirmed by carrying out theoretical calculations. [ABSTRACT FROM AUTHOR]

Single crystal X-ray diffraction analysis was employed to investigate the supramolecular properties of five 5-brominated pyrazoles in order to evaluate the role of the Br atom in the formation of halogen bonding duly recognizing that the Br atom is less polarizable than the iodine atom. Hirshfeld analysis was employed to conceive a more descriptive image of the halogen bond propensity of 5-bromopyrazoles. The compounds display Br⋯O contacts or Br⋯Br as type I or type II halogen contacts. The structural analyses revealed the isostructurality of compounds 2 and 3 while compound 5 was found to be isostructural with its iodo-analogue, suggesting the importance of the halogen contacts even if they are considered weak in nature. [ABSTRACT FROM AUTHOR]

The inorganic pyrocarbonate salt Ba[C2O5] contains twisted pyrocarbonate anions ([C2O5]2−), an atomic arrangement previously not observed in other pyrocarbonates. This unexpected additional structural degree of freedom points towards an enlarged chemical variability in this novel group of compounds. Ba[C2O5] was synthesized in a laser-heated diamond anvil cell at 30(2) GPa by heating a mixture of Ba[CO3] + CO2 to ≈ 1500(200) K. Its crystal structure was solved from single crystal synchrotron X-ray diffraction data and confirmed by density functional theory-based calculations. The two planar [CO3]2−-groups of the [C2O5]2−-anion are strongly twisted around the bridging oxygen atom. Ba[C2O5] has been observed in the pressure range of 5–30 GPa, where its symmetry is P6/m with Z = 12. [ABSTRACT FROM AUTHOR]

One open tetra-benzimidazolium salt (1) and one cyclic tetra-imidazolium salt (2) based on tetramethylbenzene were synthesized and characterized. The single crystal structure of 1 was determined by X-ray diffraction. The recognition performance of compounds 1 and 2 for guests (1 for o-phenylenediamine (OPD) and 2 for F−) was investigated via fluorescent spectra, UV/vis spectra, 1H NMR, HRMS and IR spectra. In particular, a remarkable color change (from colorless to pale brown) was observed in the recognition process of 2 for F−, which indicated that this recognition can not only be carried out by using an instrument but also by the naked eye, and this had great convenience in practice. [ABSTRACT FROM AUTHOR]

In this work, the formation of non-solvated crystalline structure [Pd(1,10-phen)(2,3,5,6-S-C6F4H)2] 1 (1,10-phen = 1,10-phenanthroline) and three different crystalline solvatomorphs [Pd(1,10-phen)(2,3,5,6-S-C6F4H)2]·S (S = C6H62, C6H6Cl 3 and C6H6Br 4) is described. In addition, the formation of crystalline solvate [Pd(1,10-phen)(2,3,4,5,6-S-C6F5)2]·C6H6Br (5) is described for comparison purposes with the former compounds. In this case, we are interested in getting deep into the knowledge of the phenomena of solvatomorphism. Therefore, we performed computational studies to determine the involved energetics features (π⋯π stacking energy phen⋯phen) of structures 1–5 to evaluate their stability associated with this interaction. In addition, graphical 2D plots of Hirshfeld surfaces were used to analyze the interactions involved in the non-solvated tecton and the solvatomorphic and solvate species. According to single-crystal X-ray diffraction results, solvatomorphs 2 and 3 are isostructural; however, 4 is non-isomorphic, despite only the difference of the solvated molecule occluded. In the case of 4 and 5, an increase in the H/F ratio in the tecton leads to the formation of different packing patterns. [ABSTRACT FROM AUTHOR]

Under the guidance of anion templates V10O286− and SO42−, the novelty of cluster assembly can be increased by using different carboxylate ligands. Herein, the synthesis, crystal structure and electrochemical properties of three anion-templated silver thiolated clusters are reported, namely V10O28@Ag46(iPrS)28(CF3CO2)12(DMF)2 (1), V10O28@Ag46(iPrS)30(CF3CO2)8(PhCO2)2(DMF)4 (2), and [SO4@Ag20(iPrS)10(PTA)3(HPTA)2]n (3, H2PTA = phthalic acid). Single-crystal X-ray diffraction analysis showed that 1 and 2 are discrete clusters V10O28@Ag46. The addition of PhCO2H in the second step of 1 leads to obtaining 2 with different organic shells. If the addition of H2PTA is made, 3 with a three-dimensional (3D) structure containing the SO42− template can be obtained. Both V10O286− and SO42− templates were generated in situ under solvothermal conditions. This work is the first where heterogeneous silver clusters containing the V10O286− anion template protected by an isopropyl thiolate ligand and a Ag20 cluster with a 3D structure are obtained. The assembly process influenced by carboxylic acid deserves to be continuously explored in the future. [ABSTRACT FROM AUTHOR]

The pathways to the formation of the series of [RuCl2(CO)2(ERR′)2] (E = S, Se, Te; R, R′ = Me, Ph) complexes from [RuCl2(CO)3]2 and ERR′ have been explored experimentally in THF and CH2Cl2, and computationally by PBE0-D3/def2-TZVP calculations. The end-products and some reaction intermediates have been isolated and identified by NMR spectroscopy, and their crystal structures have been determined by X-ray diffraction. The relative stabilities of the [RuCl2(CO)2(ERR′)2] isomers follow the order cct > ccc > tcc > ttt ≈ ctc (the terms c/t refer to cis/trans arrangement of the ligands in the order of Cl, CO, and ERR′). The yields were rather similar in both solvents, but the reactions were significantly faster in THF than in CH2Cl2. The highest yields were observed for the telluroether complexes, and the yields decreased with lighter chalcogenoethers. PBE0-D3/def2-TZVP calculations indicated that the reaction path is independent of the nature of the solvent. The substitution of one CO ligand of the intermediate [RuCl2(CO)3(ERR′)] by the second ERR′ shows the highest activation barrier and is the rate-determining step in all reactions. The observed faster reaction rate in THF than in CH2Cl2 upon reflux can therefore be explained by the higher boiling point of THF. At room temperature the reactions in both solvents proceed equally slowly. When the reaction is carried out in THF, the formation of [RuCl2(CO)3(THF)] is also observed, and the reaction may proceed with the substitution of THF by ERR′. The formation of the THF complex, however, is not necessary for the dissociation of the [RuCl2(CO)3]2. Thermal energy at room temperature is sufficient to cleave one of the bridging Ru–Cl bonds. The intermediate thus formed undergoes a facile reaction with ERR′. This mechanism is viable also in non-coordinating CH2Cl2. [ABSTRACT FROM AUTHOR]

A family of ionic ferric catecholate complexes 1–4 bearing a disubstituted 3,6-di-tert-butyl-catecholate ligand (3,6-DBCatH2) and tetradentate tris(2-pyridylmethyl)amine (TPA) was prepared and its spin transitions were investigated. Variation of the outer-sphere counteranions (PF6, BPh4, ClO4, BF4) is accompanied by changes in the magnetic behavior of the compounds under consideration. The crystal structures of complexes 1, 3 and 4 were determined by single crystal X-ray diffraction analysis at 100 K and 293 K. The complexes were characterized by the occurrence of a thermally induced spin-crossover process in the solid state with different degrees of completeness, which was confirmed by the comprehensive spectroscopic investigation (EPR, magnetic susceptibility, Mössbauer, and XAS) of the isolated compounds. Complex 4 containing BF4 anions was found to demonstrate valence tautomeric transition along with spin-crossover. This finding makes compound 4 the first salt-like mononuclear ferric catecholate complex exhibiting valence tautomerism. [ABSTRACT FROM AUTHOR]

The crystal structure of tetra-n-butylammonium chloride (TBAC) + CO2 semiclathrate hydrate that is known to have high CO2 selectivity was studied by single crystal X-ray diffraction. The presence of the CO2 gas leads to occupation of dodecahedral (D) cages by water, CO2 and chloride. This hydrate structure has three types of D cages, i.e., DL, DM and DN, with the ratio for cage number DL : DM : DN = 2 : 2 : 1. CO2 occupied DM and DN cages which were suitably distorted for the linear CO2 molecular shape. Chloride anions partly occupied the DM cages, coordinating to water molecules. The lateral distortion of the DM and DN cage leads restricted spatial CO2 distribution in the cages. The DL cages were highly distorted by the TBA cation. In DL cages, partial occupancies with both water and chloride, which coordinated to cage water molecules, were found. Contrary to the water molecules which were placed at the cage center, chloride anions were off-centred at two distinct positions due to slightly longer coordination lengths with the cage water molecules. The present analysis showed a superior CO2 capture preference of TBAC hydrate in the structural aspect. [ABSTRACT FROM AUTHOR]

A survey of all crystal structures of rubrene materials in the Cambridge Structural Database is presented. Although the chemical substitution landscape is wide, hydrogen bonding functionalities are absent. Recognition motifs frequently found in crystals are the ''slipped-cofacial'' molecular pairing, and herringbone or purely translational 3-D propagation. Packing modes are classified in terms of structure determinants, cohesive energies of pairs of molecules in closer contact computed by the CLP atomatom potential field. In these terms, crystal isomorphism with different chemical substitution is quantitatively assessed. Polymorphs are relatively few, perhaps due to poor solubilities that hamper crystallization screenings. True polymorphs are also identified by structure determinant patterns, and a new polymorph of the di-p-nitrophenyl derivative has been prepared and characterized by X-ray diffraction. Crystal morphologies of selected rubrenes have been predicted by Hartman's Periodic Bond Chain approach using PIXEL attachment energies; there is good agreement with experimental morphologies of crystals grown by sublimation. The good results obtained by CLP and PIXEL show promise for a computationally cheap access to lattice energies and morphology prediction. In general, from our overview it looks like sensitive spots in the driving forces for rubrene packing are the 4-substitution sites at the lateral rings, with substituents of moderate steric bulk. Peripheral substitution at the tetracene core seems to be less relevant. Our survey provides a structural background fostering new ideas on the synthesis and planning of physical properties of rubrenes. [ABSTRACT FROM AUTHOR]

During the synthesis of the Schiff base 2-methoxy-6-{[(tiophen-2-methyl)imino]methyl}phenol (o-HVATPNH2), a co-product was isolated and characterized. The crystal structure of this molecule, 4,10-dimethoxy-13-(thiophen-2-ylmethyl)-6,12-dihydro-6,12-epiminodibenzo[b,f][1,5]dioxocane, namely (o-VA)2TPNH2 for short, was determined by X-ray diffraction methods. The chiral compound crystallizes as a racemate in the triclinic space group P1¯ with 2 molecules per unit cell. The (o-VA)2 molecular fragment in (o-VA)2TPNH2 shows a non-crystallographic two-fold axis that enables the two molecular stereogenic centers to have the same chirality. The formation reaction mechanism for (o-VA)2TPNH2 is proposed and the structural properties of the Schiff base o-HVATPNH2 were revised. Evidence of the presence of the zwitterionic form of a Schiff base in the solid state was found. [ABSTRACT FROM AUTHOR]

KBiNb2O7 was prepared from RbBiNb2O7 by a sequence of cation exchange reactions which first convert RbBiNb2O7 to LiBiNb2O7, before KBiNb2O7 is formed by a further K-for-Li cation exchange. A combination of neutron, synchrotron X-ray and electron diffraction data reveal that KBiNb2O7 adopts a polar, layered, perovskite structure (space group A11m) in which the BiNb2O7 layers are stacked in a (0, ½, z) arrangement, with the K+ cations located in half of the available 10-coordinate interlayer cation sites. The inversion symmetry of the phase is broken by a large displacement of the Bi3+ cations parallel to the y-axis. HAADF-STEM images reveal that KBiNb2O7 exhibits frequent stacking faults which convert the (0, ½, z) layer stacking to (½, 0, z) stacking and vice versa, essentially switching the x- and y-axes of the material. By fitting the complex diffraction peak shape of the SXRD data collected from KBiNb2O7 it is estimated that each layer has approximately a 9% chance of being defective – a high level which is attributed to the lack of cooperative NbO6 tilting in the material, which limits the lattice strain associated with each fault. [ABSTRACT FROM AUTHOR]

Polyoxometalate-based organic–inorganic hybrids have attracted considerable attention due to their fascinating structures and wide application prospects. In this work, using the same building blocks, ligands and metal ions (ZnW12O406−(ZnW12), 2,2′-bipyridine (2,2′-bipy), and Cu2+), we synthesized three new POM-based hybrids by controlling the pH values of the reaction systems. These three compounds {(Zn0.6(H2)0.4W12O40)[Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)2][Cu(2,2′-bipy)(H2O)3]}2·6H2O (1), (Me4N)2{ZnW12O40[Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)3]}·5H2O (2), and {(Zn0.5(H2)0.5W12O40)[Cu(2,2′-bipy)][Cu(2,2′-bipy)(H2O)][Cu(2,2′-bipy)(H2O)2]}·5H2O (3) have been structurally characterized by single-crystal X-ray diffraction. Compound 1 appears as a dimeric cluster structure, while compounds 2 and 3 appear as a 1D chain structure and a 2D network, respectively. The semiconducting properties of compounds 1–3 are different, which was demonstrated by band gap (Eg) and photocurrent response measurements. Compound 3 can efficiently catalyze the photooxidation of toluene to benzaldehyde with high selectivity using molecular oxygen as the oxidant component. Moreover, compound 3 was recycled and reused three times without significant degradation in conversion and selectivity. In addition, the mechanism of the photocatalytic reaction was also investigated. [ABSTRACT FROM AUTHOR]

The tribrominated arenes 1,3,5-C6(E-CH＝CHAr)3Br3 (Ar = Ph, (I), p-To (I′)), add oxidatively to [Pd(dba)2] ([Pd2(dba)3]·dba) in the presence of two equivalents of a phosphine (PPh3 or PMe2Ph) to form the monopalladated complexes trans-[Pd{C6(E-CH＝CHAr)3Br2}Br(L)2] (Ar = Ph, L = PPh3 (1a), Ar = p-To, L = PPh3 (1a′), Ar = Ph, L = PMe2Ph (1b)), while the reaction in a 1 : 2 : 4 arene : Pd : PMe2Ph molar ratio affords the dipalladated complex [{trans-PdBr(PMe2Ph)2}2{μ2-C6(E-CH＝CHPh)3Br}] (2b). Both I and I′ add oxidatively to 3 equivalents of [Pd(dba)2] in the presence of the chelating N-donor ligand tmeda (N,N,N′,N′-tetramethylethylenediamine) to form the tripalladated complexes [{PdBr(tmeda)}3{μ3-C6(E-CH＝CHAr)3}] (Ar = Ph, (3c), p-To (3c′)). Complex 3c reacts with PMe3 to form [{trans-PdBr(PMe3)2}3{μ3-C6(E-CH＝CHPh)3}] (3d). Compound 3c also reacts with CO to give the novel dipalladated indenone [2-Ph-4,6-{PdBr(tmeda)}2-5,7-(E-CH＝CHPh)2-inden-1-one] (4). The crystal structures of 1a′ and 1b were determined by X-ray diffraction studies. [ABSTRACT FROM AUTHOR]

First principles calculations of the α-quartz phase of Si1−xSnxO2 predict great benefits of the substitution of Si by Sn with the d11 piezoelectric constant (5.72 pC N−1) for Si0.8Sn0.2O2, which is predicted to be twice that of quartz (2.85 pC N−1). Furthermore, the value of the d11 piezoelectric constant increases four times in the case of substitution with tin in comparison with that for germanium. The first Sn-substituted α-quartz single crystals have been grown under hydrothermal conditions, but the degree of substitution is still very low (xmax = 0.001). The analyses of additional compounds recovered after growth runs indicate that Sn crystallizes in a six-fold coordination with silicon by forming a mixed Si/Sn oxide in the autoclave, which may explain the low degree of substitution in the α-quartz single crystals. A new compound with the formula Na2Si4SnO9(OH)4 is identified, and the structure is determined. This paper predicts high performance of the Sn-substituted single quartz crystals. Crystal growth experiments show that Sn substitution is possible in the structure of quartz-type by using a crystal growth process favoring the formation of four-fold coordinated Sn species [SnO4] in the solution for obtaining a high Sn ratio in the quartz-crystals. [ABSTRACT FROM AUTHOR]

Well-dispersed uniform spheres (∼0.7–1.5 μm in diameter) of YPO4 and (Y,Ln)PO4 (Ln = Eu, Tb, Dy, Ho, Tm, Ce, and Eu/Tb) tetragonal phosphate hydrates have been directly synthesized via microwave-assisted processing. The polycrystalline spheres, which are made of confined 10–17 nm nanocrystals, are direct solid solutions rather than a mechanical mixture of individual particles. Their growth follows an aggregation process, maintaining the composition of the material. The phosphate hydrates converted into anhydrous tetragonal materials via calcination, and the spherical shape and excellent dispersion of the original particles were well retained up to 1000 °C. Upon UV excitation, the YPO4:Ln3+ samples exhibit characteristic emissions of Ln3+ (Ln = Eu, Tb, Dy, Ho, Tm, and Ce) and yield red, green, near white, green, blue, and blue-green emissions, respectively. The color-tunable emissions (from green to red) can be varied by increasing the Eu content, and the Tb3+→ Eu3+ energy transfer process was observed for the tetragonal phosphate in the Y/Tb/Eu system. The efficiency of the Tb3+→ Eu3+ energy transfer was discovered to be ∼28% for (Y0.88Tb0.02Eu0.10)PO4. The thermal stability of (Y0.88Tb0.02Eu0.10)PO4 is lower than that of (Y0.98Tb0.02)PO4 and (Y0.95Eu0.95)PO4. Thus, the 5D4→7F5 transition of Tb3+ at 546 nm splits into UGRAPHIC DISPLAY="INLINE" ID="UGT1" SRC="UGT1"/→7F5 (at ∼538–546 nm) and UGRAPHIC DISPLAY="INLINE" ID="UGT2" SRC="UGT2"/→7F5 (at ∼557 nm) transitions during the heating process. This phenomenon has been ascribed to the variation of the Tb3+ crystal environment. The UGRAPHIC DISPLAY="INLINE" ID="UGT3" SRC="UGT3"/ energy level gradually shifts to a higher one at an elevated temperature, inducing more and more excited electrons transferring from the higher UGRAPHIC DISPLAY="INLINE" ID="UGT4" SRC="UGT4"/ energy level to the lower UGRAPHIC DISPLAY="INLINE" ID="UGT5" SRC="UGT5"/ one via nonradiative relaxation. Therefore, an enhanced emission intensity at ∼557 nm (UGRAPHIC DISPLAY="INLINE" ID="UGT6" SRC="UGT6"/→7F5 transition) and a weakened one at ∼538–546 nm (UGRAPHIC DISPLAY="INLINE" ID="UGT7" SRC="UGT7"/→7F5 transition) were observed. (Y0.95Eu0.05)PO4/PVA transparent films were successfully fabricated by solution casting, and they exhibit both outstanding flexibility and high transmittances of ≥83% in the 400–850 nm region. The hybrid films can be coated on paper money for anti-fake labeling applications. [ABSTRACT FROM AUTHOR]

Elimination of the chloride ion from the [(PPh3)AuCl] complex using silver triflate (AgOTf) in the presence of 2,2′-bipyridine R2bpy (the Au : R2bpy molar ratio is 2 : 1) in dichloromethane at room temperature leads to dinuclear gold(I) complexes [(PPh3Au)2(μ-R2bpy)](OTf)2 (R2bpy = bpy (1), dbbpy (2), CH3Obpy (3), 3-CO2CH3bpy (4), 4-CO2CH3bpy (5)) in high yields. The crystal structures for all compounds were determined using X-ray diffraction analysis. In all structures, gold ions are in a typical linear environment, and the bipyridine molecule is twisted, which allows intramolecular aurophilic interactions. Relatively short Au(I)⋯Au(I) contacts (3.1262 (2)–3.400 (1) Å) are found in structures 3–5. DFT calculations show the presence of bond critical points (3, −1) for aurophilic interactions in these structures. In structures 1 and 2, the Au(I)⋯Au(I) distances are noticeably larger and equal to 4.479 (1) and 4.589 (1) Å respectively; there are no bond critical points (3, −1) for aurophilic interactions. All complexes show photoluminescence in solid state at room temperature when excited at 300 nm in a wide spectral range: from blue or blue-green emission (400–460 nm) for 1–4 to orange emission (580 mn) for 5. The lifetimes of the excited state are in the microsecond range which is characteristic of phosphorescence. TD-DFT calculations reveal that electronic transitions of different nature are responsible for the photoluminescence of these compounds. [ABSTRACT FROM AUTHOR]

Solvates are important forms of crystalline materials and their formation and desolvation would affect the quality of the final products. In this work, to better understand the desolvation mechanism of solvates and its effect on the properties of the final products, cefathiamidine was selected as the model compound to investigate the influence of intermolecular interactions and the crystal structure on the desolvation process. Three new solvates and one reported solvate of cefathiamidine, including acetonitrile solvate monohydrate S1, acetone solvate monohydrate S2, n-propanol solvate 1.5 hydrate S3 and isopropanol solvate S4, were obtained by solution crystallization and their structures were determined by single crystal X-ray diffraction. The results indicated that the cefathiamidine molecule is highly conformationally flexible and eight conformations were observed in these solvates. The different solvates exhibit different intermolecular interactions, packing patterns and crystal stabilities. Furthermore, the desolvation processes of the solvates were systematically investigated by various analytical techniques and were analyzed based on the intermolecular interactions, molecular networks, void types, proportion of voids and packing patterns. The results showed that the desolvation of solvates S1 and S2 followed a cooperative–reorganization mechanism while the desolvation of solvate S3 and solvate S4 followed a destruction–reconstruction mechanism and a destruction–collapse mechanism, respectively. Finally, the corresponding mechanisms of the different solvates were proposed. [ABSTRACT FROM AUTHOR]

Five new salts of the 3,4-dicyano-2-(dicyanomethylene)-5-methyl-6-phenyl-2H-pyridin-1-ide anion (TCPy−) with lithium, sodium, potassium, rubidium and cesium cations were synthesized and structurally characterized by a single-crystal X-ray diffraction method. The solid state photoluminescence characteristics of the prepared salts were studied. The crystallographic features of the crystal packing which are responsible for the emission band position were investigated. Quantum-chemical calculations were carried out to explain the correlation between emission maxima and the crystal structure. [ABSTRACT FROM AUTHOR]

In this paper we describe the synthesis, characterization, and X-ray crystal structures of two ligands, diethyl-N,N′-bis(p-tolyl)malonimidate and 1,3-bis(dimethylamino)-N,N’-bis(p-tolyl)propanediimidate. Their corresponding rhodium(i) dicarbonyl, dimethylaluminium, and bis-ligated zinc complexes have also been prepared and characterized. The donor properties of the ligands have been studied and have been compared to those of the traditional anionic N,N’-chelating ligand nacnac. [ABSTRACT FROM AUTHOR]

A new 3D Ag(I)-based HE-MOFs, [Ag2(TABT)(NO3)2]n, where TABT represents 4,4′,5,5′-tetraamine-3,3′-bis-1,2,4-triazole, was synthesized and fully characterized by single-crystal X-ray diffraction, IR, 1H-NMR and elemental analyses. Its thermal behaviors were investigated by thermogravimetry and differential scanning calorimetry (TG-DSC) techniques while the thermo-kinetic parameters of exothermic process were calculated by Kissinger and Ozawa methods. The results indicate that the compound possesses an excellent thermal stability with a high decomposition temperature up to 301.2 °C. In addition, its detonation properties and sensitivity suggest that the title Ag-based salt can be used as a potential explosive. [ABSTRACT FROM AUTHOR]

The reaction of the unsymmetrical N-heterocyclic carbenes 1-(2,4,6-trimethylphenyl)-3-(adamantyl)imidazolin-2-ylidene (IAdMes, 1a) and 1-(2,6-diisopropylphenyl)-3-(adamantyl)imidazolin-2-ylidene (IAdDipp, 1b) with trimethylsilyl azide furnished the 2-(trimethylsilylimino)imidazolines 2a (ImAdMesNSiMe3) and 2b (ImAdDippNSiMe3). Desilylation by stirring in methanol gave the corresponding imidazolin-2-imines 3a (ImAdMesNH) and 3b (ImAdDippNH). 2a and 2b were treated with [TiCl4(THF)2] (THF = tetrahydrofuran) and [CpTiCl3] (Cp = η5-C5H5) to form the mono- and bis(imidazolin-2-iminato) titanium(IV) complexes [(ImAdRN)TiCl3] (4, R = Mes, Dipp), [Cp(ImAdRN)TiCl2] (5, R = Mes, Dipp), and [(ImAdRN)2TiCl2] (6, R = Mes, Dipp). The crystal structures of all compounds except 2b were determined by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Mixed-anion compounds are among the most promising systems to design functional materials with enhanced properties. Among the phosphate–sulfate species, the [SO4]2− and [PO2F2]− tetrahedra are known and give rise to structural versatility. However, to date, the crystal structures of phosphate–sulfates with the coexistence of two distinct anion groups ([S2O7]2− and [PO2F2]−) in one compound are unknown. Here, a novel type of fluorooxophosphorsulfate, K4(PO2F2)2(S2O7) (KSPOF), is designed and synthesized via a high-temperature method in a closed system. The crystal structure is derived from single-crystal X-ray diffraction (C2/c, a = 13.000(10) Å, b = 7.5430(10) Å, c = 19.010(10) Å, β = 130.070(10)°, and Z = 4). It is the first fluorooxophosphorsulfate with mixed-anion building units ([S2O7]2− and [PO2F2]−) and a unique drum-like cluster was found, which enriches the diversity of structures for fluorooxophosphorsulfate systems. Furthermore, the theoretical calculations indicate that KSPOF possesses moderate birefringence, which mainly originates from the distorted [PO2F2]− tetrahedron. [ABSTRACT FROM AUTHOR]

Three lanthanide polymers {[Ln(TMCA)(DEF)(H2O)]·(CH3CN)}n (Ln = Eu 1; Tb 2; Gd 3; H3TMCA = 4′,4′,4′-[(trimethylamino)]-tris[(1,1′-biphenyl)-2-carboxylic acid]) were synthesized under solvothermal conditions. The coordination polymers were characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and single-crystal X-ray diffraction. Single crystal X-ray diffraction analyses showed that the complexes 1, 2 and 3 are isostructural 2D coordination networks with a point symbol of {44·62}. Complexes 1 and 2 exhibit red and green emission, assigned to the 5D0 → 7FJ (J = 0–4) transitions of the Eu3+ ion and 5D4 → 7FJ (J = 6–2) transitions of the Tb3+ ion, respectively. The luminescence explorations reveal that the Eu-MOF possesses favorable selectivity and sensitivity for testing Fe3+ in CH3OH solutions. Additionally, color tuning was easily achieved by varying the europium : terbium metal ratios in the reaction mixtures. [ABSTRACT FROM AUTHOR]

Two novel semicarbazide [HL1, 1, 1-((4-nitrophenyl)(phenyl)methylene)semicarbazide] and thiosemicarbazide [HL2, 2, 1-((4-nitrophenyl)(phenyl)methylene)thiosemicarbazide] ligands were generated from 4-nitrobenzophenone and the corresponding (thio)semicarbazide precursors. Compounds 1 and 2 were fully characterized and their X-ray crystal structures were established. These organic derivatives were further applied as bioactive building blocks for the self-assembly synthesis of silver(I) coordination compounds. The reactions of silver(I) nitrate with HL1/HL2 in the presence of aqueous NH4OH resulted in new silver(I) coordination compounds formulated as [Ag(HL1)(NO3)]·H2O (3) and [Ag6(μ3-L2)6] (4). These complexes were characterized by standard methods (FT-IR, NMR, ESI-MS, and elemental analysis) as well as single-crystal X-ray diffraction. The structure of 3 features a two-coordinate silver(I) center with a distorted linear {AgNO} geometry, wherein an unusual coordination of HL1 through the nitrogen atom of the amine group is realized. The structure of 4 reveals a discrete Ag6 cluster composed of two joined trisilver(I) rings, wherein the three-coordinate Ag(I) centers adopt an {AgNS2} environment. The antimicrobial activity of 1–4 was screened against Gram-positive (S. epidermidis and S. aureus) and Gram-negative (P. aeruginosa and E. coli) bacteria. Compound 4 presented antimicrobial activity against Gram-positive bacteria, including the ability to impair biofilm formation. This study thus contributes to a still limited research area on the development of new silver coordination compounds with potential antibiofilm activity. [ABSTRACT FROM AUTHOR]

At ambient pressure, guanidinium ethoxysulfonate (GES) crystallizes in two forms, α-GES and β-GES, in which the cations and anions are H-bonded into supramolecular 2D motifs. It has been shown that the non-polar α-GES built of bilayers cannot be transformed into the ferroelectric β-GES of a single-layer architecture, by thermal stimulation. However, this transition can be accomplished under pressure. The transition is irreversible, is of reconstructive-type, and proceeds with a rate depending on numerous factors like the pressure magnitude and duration, and temperature variations. The slow-kinetic processes of transformation, once triggered by pressure, run for a long time after releasing the pressure. The high-pressure dielectric studies revealed the complexity of the p–T phase diagram of β-GES. Three of the four new crystalline phases, which emerge under pressure between the ferroelectric and paraelectric phases, exhibit properties indicating a possible modulation of the crystal structure. The high-temperature phase I of β-GES has been crystallized in situ in a glass capillary and its structure has been determined by single-crystal X-ray diffraction. The structural and calorimetric data evidenced that the transition between phases I and II of β-GES has a reconstructive character, but it is fully reversible. [ABSTRACT FROM AUTHOR]

The new Y2Co3Ga9 and Gd3Ru4Al12 type representatives M2T3Al9 (M = Ca, Sr, Eu; T = Ir, Pt) and M3Rh4Al12 (M = Ca, Eu) have been synthesized from the elements by heating the respective elemental compositions in sealed tantalum tubes. The samples were analysed by powder X-ray diffraction to check their purity. By applying different temperature treatments, their phase purity and crystallinity were enhanced. The crystal structures of Ca3Rh4Al12 and Eu3Rh4Al12 (hexagonal Gd3Ru4Al12 type, P63/mmc) as well as Ca2Ir3Al9 and Ca2Pt3Al9 (orthorhombic Y2Co3Ga3 type, Cmcm) were refined from single-crystal X-ray diffraction data. All structures can be described based on distorted cube-like T@Al8 units that are connected to form strands. Additionally, an Al11 supertetrahedral building block can be identified within the structures. While the trigonal bipyramidal core of the cluster contains substantial bonding interactions in the case of the M3Rh4Al12 members, the connection via common edges in the case of the M2Ir3Al9 compounds seems to weaken these interactions. The differences in the bonding situation and the question why these different structure types are formed for the different transition metals has been targeted by quantum-chemical calculations. The calculated formation energy using three different reaction paths suggests that the stability of these phases is highly dependent on the side phases involved, even though Ca3T4Al12 phases are in general thermodynamically more favourable. According to the Bader analysis of the two polyanions, an improved covalent bonding can be observed in the [T4Al12]δ− over the [T3Al9]δ− framework. [ABSTRACT FROM AUTHOR]

By examining the crystal structures of the self-assemblies of 1H,1′H-[3,3′]bipyridinyl-6,6′-dione 1 and its coordination structure with Co(II), to form novel CP-671, our study demonstrates the tendency of dipyridones to generate predictable patterns by hydrogen bonding depending on the crystallization conditions and the potential of pyridone ligating groups to design novel coordination polymers with structural diversity. The two structures of 1 elucidated by single-crystal X-ray diffraction show a cyclic dimer and zigzag chain to generate fascinating hydrogen bond frameworks. A two-dimensional coordination polymer structure (CP-671) is obtained by the linkage of 1 with a cobalt cation according to a known coordination mode of the 2-pyridone ligating group. [ABSTRACT FROM AUTHOR]

Four new ionic diimine Cu(I) complexes with general formula [Cu(POP)(NN)]BF4 have been synthesized by convenient methods from readily available starting materials. All the complexes were characterized by a range of spectroscopic, electrochemical, and computational techniques and, in the cases of 1, 2, and 3, by single crystal X-ray diffraction. The complexes are emissive in the solid state at ambient temperature and the emission maxima are located in the orange range. Furthermore, the suitability of these complexes for application in organic light-emitting diodes (OLEDs) has been demonstrated in a solution-processed device. [ABSTRACT FROM AUTHOR]

Low dimensional organic–inorganic halide perovskites have gained a great deal of attention due to their augmented performance in optoelectronic applications, such as solid-state lighting and display. Such compounds consist of a layered structure, such as a multiquantum well structure, where the broadband white-light emission has been observed from diverse metal halide structures. Their broadband emission is ascribed to the self-trapped excitons (STE), which are generated from a deformable structure due to the strong electron-phono coupling. The intensity of the broadband emission is improved by lowing the dimensionality to a 1D perovskite due to the enhanced STE. Herein, we report zigzag edge-sharing 1D perovskites, (4-(aminomethyl)pyridinium)PbBr4 (C6H10N22+ = AMP2+), and (AMP)PbCl4, which are intrinsic deformative structures due to a zigzag connected PbBr6 (or PbCl6) octahedra. Through single crystal X-ray diffraction, we have identified the local lattice distortion from the octahedral environmental of Pb2+ in the inorganic sheet. The temperature dependent photoluminescence data indicate that the unusual broadband emission in zigzag edge sharing (AMP)PbBr4 and (AMP)PbCl4 perovskites is attributed to an intrinsic bulk property, in which photogenerated carriers cause the lattice distortion through electron–phonon coupling. When comparing two compounds, (AMP)PbCl4 gives more remarkable efficient white-light emission than (AMP)PbBr4, because the inorganic structure of (AMP)PbCl4 is a much larger distortion than that of (AMP)PbBr4, which results in a high color rendering index of 90.21. These established results allow us to systematically design white-light emitting materials from 1D perovskites by fine-tuning their crystal structures. [ABSTRACT FROM AUTHOR]

Six Zn/Cd metal–organic frameworks (MOFs), {[Zn2(dppa)(bpy)2(H2O)]·H2O}n (1), {[Zn2(dppa)(phen)2(H2O)]·3H2O}n (2), [Cd(H2dppa)(bpy)]n (3), {[Cd2(dppa)(dye)]·H2O}n (4), {[Cd4(dppa)2(H2O)9]·H2O}n (5) and {[Cd2(dppa)(bpe)2(H2O)]·H2O}n (6) (H4dppa = 5-(3′4′-dicarboxylphenoxy)isophthalic acid, phen = 1,10-phenanthroline, bpy = 2,2′-bipyridine, dye = 2,2′-dipyridylamine, bpe = 1,2-bis(4-pyridy) ethane), were synthesized and structurally characterized by elemental analyses, plasma (ICP) spectrometry, IR spectroscopy, and single-crystal X-ray diffraction analyses. 1–3 are 1D ring chains. 4 shows a 2D bilayer network based on a tetranuclear cadmium cluster linked by (dppa)4− ligands. 5 displays a 2D bilayer network based on a trinuclear cadmium cluster, in which (dppa)4− ion shows two different coordination modes. In contrast to the above MOFs, 6 possesses a 3D network structure based on dinuclear cadmium units cross-linked by (dppa)4− and bpe ligands. For 1–6, weak hydrogen bonding and π⋯π stacking contacts link the discrete 1D chains or 2D networks to form high-dimensional supramolecular structures. Especially, in 1–6, (dppa)4− ligand displays seven different coordination modes and conformations, which may show natural synergy in the structural diversity of the resulting MOFs. The remarkable characteristic of these frameworks is that 2 demonstrates highly selective and sensitive bifunctional luminescent sensing towards acetone and Fe3+ ion. In addition, the thermal stabilities and luminescence properties of the MOFs were studied. [ABSTRACT FROM AUTHOR]

Nitrogen-rich energetic compound 5,5′-dinitramino-3,3′-methylene-1H-1,2,4-bistriazole (H2DNAMT (1)) and its transition metal salts, including [Co(DNAMT)(H2O)4]·2H2O (2), [Ni(DNAMT)(H2O)4]·2H2O (3), [Zn(DNAMT)(H2O)4]·2H2O (4), [Cd(DNAMT)(H2O)4]·2H2O (5) and [Fe(BNATO)(H2O)4]·2H2O (6), were synthesized and characterized by elemental analysis, IR spectroscopy and single-crystal X-ray diffraction analysis. The crystal structures of compounds 2–5 are similar, and crystallize in orthorhombic systems with the Pnma space group, whereas compound 6 belongs to the orthorhombic system with the Pccn space group. The densities of these salts are in the range of 1.832 (compound 2) to 1.999 g cm−3 (compound 5). In compound 6, H2DNAMT was oxidized to bis(3-nitroimino-2H-1,2,4-triazole-5-yl)methanone (H2BNATO) due to the trivalent iron anion. The NBO charge of H2DNAMT and BNATO2− was calculated by density functional theory, to understand their coordination modes. The thermal decomposition processes, non-isothermal kinetics, enthalpies of formation and sensitivities of these compounds were investigated in detail to argue their potential application as energetic materials. [ABSTRACT FROM AUTHOR]

Structures of three polymorphs of 1-acetylpyrene were determined using single-crystal X-ray diffraction and their solid state luminescence was investigated. While the formerly known 1AP-α polymorph, with its herringbone packing motif, is proved to be non-luminescent, the newly discovered polymorphs β and γ, with crystal structures based on π⋯π-dimers, luminesce intensely in blue and green accordingly. This discovery contradicts a possibility of systematic control over the packing of pyrene units in crystals by progressive addition of acetyl groups, formerly claimed for n-acetyl-pyrenes. [ABSTRACT FROM AUTHOR]