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Developing new methods to control the size and shape of the helical structures adopted by foldamers is highly important as the secondary structure displayed by these supramolecular scaffolds often dictates their activity and function. Herein, we report on a systematic study demonstrating that the helical pitch of ortho‐azobenzene/2,6‐pyridyldicarboxamide foldamers can be readily controlled through the nature of the terminal functionality. Remarkably, simply through varying the end group of the foldamer, and without modifying any other structural features of the scaffold, the helical pitch can be over doubled in magnitude (from 3.4 Å–7.3 Å). Additionally, crystallographic analysis of a library ten foldamers has identified general trends in the influence of a range of terminal functionalities, including carboxylbenzyl (Cbz), diphenylcarbamyl (N(Ph)2), ferrocene (Fc) and tert‐butyloxycarbonyl (Boc), in controlling the folding behaviour of these supramolecular scaffolds. These studies could prove useful in the future development of functional foldamers which adopt specific sizes and shapes. [ABSTRACT FROM AUTHOR]

A highly selective approach with high yields of two diastereomeric silicon‐stereogenic menthoxysilanes, (RSi)‐3 and (SSi)‐3, introduced by Sommer et al. could be established as well as investigated in detail using different analytical tools. Single‐crystal X‐ray diffraction analysis was used to examine the different crystallization rates while Hirshfeld surface analysis was applied to extend supramolecular interactions in the solid state which showed stronger hydrogen bridges for the faster crystallizing diastereomer (SSi)‐3. In addition, similar ground‐state energies haven been found for both diastereomers by DFT calculations. Subsequent NMR studies showed stable Si‐configurations wherein epimerization only started after more than 4 hours at 110 °C. Access to both diastereomers with opposite configuration at the stereogenic silicon center is achievable in high yields and high stereochemical purity using only naturally occurring (−)‐menthol as a reagent. [ABSTRACT FROM AUTHOR]

Oxyapatites A10(GeO4)6O2 (A – alkaline, rare‐earth elements) are considered promising materials for applications in solid‐state lighting and non‐contact thermometry. The temperature dynamics of the oxygen sublattice have a crucial influence on the luminescent properties of these optical hosts. Here, the structural evolution with temperature of germanates with the general formula ALa9(GeO4)6O2 (A – Li, Na, K, Rb) is investigated, using X‐ray and neutron powder diffraction methods. These compounds crystallize in space‐group P63/m. NPD experiments helped to determine the oxygen and alkaline metal positions. Thermally‐induced reentrant structural transitions relating to the oxygen in the apatite channel are discovered for the first time. In the example of Eu‐doped RbLa9(GeO4)6O2 and KLa9(GeO4)6O2, it is demonstrated that the luminescence of the Eu3+ ion is influenced by small changes in the crystal structure. [ABSTRACT FROM AUTHOR]

Azoles are widely used as bioactive substances, herbicides, catalysts, corrosion inhibitors, polymeric compositors, organometallic ligands, and optical elements' components. The interaction with water plays a crucial role in many applications of azoles. The objective of this study is to observe the molecular interaction and structural transformations of 1,2‐ and 1,3‐diazoles', 1,2,3‐ and 1,2,4‐triazoles' complexes with water molecules. We have selected the most valuable for application and theoretical interest azoles with different molecular structures, which have allowed us to consider the basic features of their aqueous complexes. We used the IR study method allowing to fix water intermediates in the solid phase. We have also employed the hybrid B3LYP functional DFT method with GD3BJ dispersion correction. At the cluster formation, the hydrogen atom transfer arises, providing a labile spatial arrangement of the water system. The formation of azoles' complexes with a hydronium ion having relatively low binding energy allows the reshaping of the complexes' structure at the hydrogen atom cluster‐to‐cluster transition. The complex formation is accompanied by the hydrogen atom transfer with the participation of both water and azole hydrogen atoms. This transfer provides the mobile spatial arrangement of clusters and hydrogen atom transition from donor to acceptor centers. [ABSTRACT FROM AUTHOR]

Supramolecular have promising application prospects owing to their catalytic, self‐healing, and stimulus‐responsive functions. Pyridylethynylimidazole‐based supramolecular synthons with fluorescent properties have been developed. 4‐(2‐Pyridylethynyl)‐5‐arylethynyl‐1H‐imidazole derivatives 1 with different substituents at the 4‐ and 5‐positions of the imidazole skeleton were prepared using a step‐by‐step Sonogashira coupling reaction. The fluorescence maxima of phenyl‐ and methoxyphenyl‐substituted derivatives 1a and 1c were independent of solvent polarity. On the other hand, ester‐ and cyano‐substituted 1b and 1d showed bathochromically shifted fluorescence maxima in highly polar solvents. In crystals, the 4‐(2‐pyridylethynyl)‐5‐arylethynyl‐1H‐imidazole derivatives formed a supramolecular cyclic tetramer structure via two hydrogen bonds: one was between N─H in imidazole and N in pyridine, and the other was between C─H in imidazole and N in imidazole. Introducing the pyridine ring as a hydrogen bond acceptor, in addition to the imidazole ring, promoted the unique cyclic tetramer structure formation. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: To better understand the impact of different anions on the structures and SCO properties of the CoII SCO complexes, six new complexes [Co(terpy‐CH2OH)2]A2·sol (terpy‐CH2OH = 4′‐(hydroxymethyl)‐2,2′;6′,2″‐terpyridine, A = Br– (1, sol = 1.5H2O), I– (2), N3– (3, sol = 2H2O), H3BCN– (4), OTf– (5), and TsO– (6, sol = 4H2O·CH3CN), have been synthesized and characterized. All six compounds consist of mononuclear [Co(terpy‐CH2OH)2]2+ cations and charge‐balancing anions that differ in size, shape, and hydrogen bonding capacity. Complexes 1, 2, 3, and 6 displayed incomplete gradual SCO transitions, whereas 4 and 5 exhibited abrupt hysteretic spin transitions with loops of 12 and 16 K (250.0—262.0 K for 4, and 370.0—386.0 K for 5, respectively), closely resembling our previously reported complexes with SCN– and SeCN– anions. The occurrence of the order‐disorder transition of the CH2OH groups and their transition temperatures are determined by the size and hydrogen bonding capability of the anions. Remarkably, the transition temperatures of complexes with H3BCN–, SCN–, OTf–, and SeCN– anions exhibit an upward trend as the size and mass of the anions increase, as confirmed through detailed single crystal structure analyses conducted in both high‐spin and low‐spin states for all four complexes. [ABSTRACT FROM AUTHOR]

A series of novel and previously published organoantimony compounds (RnSbX3−n, X = Cl, Br; R = o-tolyl, 2,6-xylyl, 1-naphthyl, and 9-anthracenyl), were synthesized and characterized. In addition, single-crystal X-ray diffraction was employed to elucidate the molecular structures of all solid species. These compounds display non-covalent intermolecular interactions in the form of edge-to-face, π···π stacking, and CH3···π interactions, and the effects of the substituent type and substituent bulk on the nature of these interactions present will be highlighted and discussed. [ABSTRACT FROM AUTHOR]

Nitridophosphates are in the focus of current research interest due to their structural versatility and properties, such as ion conductivity, ultra‐incompressibility and luminescent properties when doped with suitable activator ions. Multinary representatives often require thorough investigation due to the competition with the thermodynamically more stable binary and ternary compounds. Another point of concern is the synthetic control of structural details, which is usually limited by conventional bottom‐up syntheses. In this study, we report on the synthesis and characterization of the quaternary nitridophosphate CaLi2PN3. Various synthesis protocols were used for the preparation of CaLi2PN3, including the novel nitridophosphate double salt approach. The crystal structure was solved and refined from single‐crystal X‐ray diffraction data and confirmed by Rietveld refinement, solid‐state NMR spectroscopy, EDX measurements and low‐cost crystallographic calculations. The experimental results were corroborated by DFT calculations, which revealed the electronic band structure. Formation energy calculations allowed conclusions to be drawn about the stability in comparison to the initial ternary nitridophosphates. The synthesis of CaLi2PN3 exemplifies the enormous potential of medium‐pressure syntheses in the field of nitridophosphate research. Furthermore, the presented new synthesis route allows a certain degree of structural control, which is a promising addition to previous synthesis strategies in nitridophosphate chemistry. [ABSTRACT FROM AUTHOR]

Chalcogen bonds (ChB) are moderately strong, directional, and specific non‐covalent interactions that have garnered substantial interest over the last decades. Specifically, the presence of two σ‐holes offers great potential for crystal engineering, catalysis, biochemistry, and molecular sensing. However, ChB applications are currently hampered by a lack of methods to characterize and control chalcogen bonds. Here, we report on the influence of various substituents (halogens, cyano, and methyl groups) on the observed self‐complementary ChB networks of 2,1,3‐benzoselenadiazoles. From molecular electrostatic potential calculations, we show that the electrostatic surface potentials (ESP) of the σ‐holes on selenium are largely influenced by the electron‐withdrawing character of these substituents. Structural analyses via X‐ray diffraction reveal a variety of ChB geometries and binding modes that are rationalized via the computed ESP maps, although the structure of 5,6‐dimethyl‐2,1,3‐benzoselenadiazole also demonstrates the influence of steric interactions. 77Se solid‐state magic‐angle spinning NMR spectroscopy, in particular the analysis of the selenium chemical shift tensors, is found to be an effective probe able to characterize both structural and electrostatic features of these self‐complementary ChB systems. We find a positive correlation between the value of the ESP maxima at the σ‐holes and the experimentally measured 77Se isotropic chemical shift, while the skew of the chemical shift tensor is established as a metric which is reflective of the ChB binding motif. [ABSTRACT FROM AUTHOR]

Ammeline is a simple, readily available, molecular compound, which has been known for nearly 200 years. Despite that, no proper structural characterization of ammeline has been conducted so far. For this reason, the prevalent tautomeric form of ammeline in the solid remained unknown to this date. In the course of this study, its crystal structure was finally established by single‐crystal X‐ray diffraction. In this structure, ammeline is exclusively found as its 4,6‐diamino‐1,3,5‐triazin‐2(1H)‐one tautomer and adopts layered structure with an exceptionally high hydrogen bond density. Ammeline shows an interesting amphoteric behavior. Therefore, the synthesis and structural characterization of some of its salts were carried out to investigate the influence of the protonation degree on its molecular structure. In particular, the crystal structure of silver ammelinate monohydrate was solved as the first reported structure containing deprotonated ammeline. Moreover, the crystal structures of three different modifications of ammelinium perchlorate were elucidated and the transformation conditions between them were studied. Lastly, the crystal structure of ammelinediium diperchlorate monohydrate, containing unprecedented doubly protonated ammeline, was determined. The products' thermal behavior was studied by differential thermal analysis and thermogravimetric analysis. The perchlorate salts were additionally examined for their potential as insensitive high‐energy‐density materials. [ABSTRACT FROM AUTHOR]

Sn3P8N16 combines the structural versatility of nitridophosphates and Sn within one compound. It was synthesized as dark gray powder in a high‐pressure high‐temperature reaction at 800 °C and 6 GPa from Sn3N4 and P3N5. The crystal structure was elucidated from single‐crystal diffraction data (space group C2/m (no. 12), a=12.9664(4), b=10.7886(4), c=4.8238(2) Å, β=109.624(1)°) and shows a 3D‐network of PN4 tetrahedra, incorporating Sn in oxidation states +II and +IV. The Sn cations are located within eight‐membered rings of vertex‐sharing PN4 tetrahedra, stacked along the [001] direction. A combination of solid‐state nuclear magnetic resonance spectroscopy, 119Sn Mössbauer spectroscopy and density functional theory calculations was used to confirm the mixed oxidation of Sn. Temperature‐dependent powder X‐ray diffraction measurements reveal a low thermal expansion of 3.6 ppm/K up to 750 °C, beyond which Sn3P8N16 starts to decompose. [ABSTRACT FROM AUTHOR]

Sn3P8N16 combines the structural versatility of nitridophosphates and Sn within one compound. It was synthesized as dark gray powder in a high‐pressure high‐temperature reaction at 800 °C and 6 GPa from Sn3N4 and P3N5. The crystal structure was elucidated from single‐crystal diffraction data (space group C2/m (no. 12), a=12.9664(4), b=10.7886(4), c=4.8238(2) Å, β=109.624(1)°) and shows a 3D‐network of PN4 tetrahedra, incorporating Sn in oxidation states +II and +IV. The Sn cations are located within eight‐membered rings of vertex‐sharing PN4 tetrahedra, stacked along the [001] direction. A combination of solid‐state nuclear magnetic resonance spectroscopy, 119Sn Mössbauer spectroscopy and density functional theory calculations was used to confirm the mixed oxidation of Sn. Temperature‐dependent powder X‐ray diffraction measurements reveal a low thermal expansion of 3.6 ppm/K up to 750 °C, beyond which Sn3P8N16 starts to decompose. [ABSTRACT FROM AUTHOR]

The ternary amide Na2Ba(NH2)4 was synthesized at ammonothermal conditions (870 K, 135 MPa) in custom‐built high‐pressure autoclaves. The compound was structurally characterized using X‐ray diffraction and crystallizes in space group Pccn (no. 56) with lattice parameters a=10.6492(2), b=7.8064(2) and c=8.1046(2) Å. To the best of our knowledge, the structure type has not yet been observed in any ternary amide before and can be described as a defective variant of the NaCl structure type. The presence of amide ions in the compound is verified by Fourier‐transform infrared (FTIR) spectroscopy and the experimental spectrum is compared to the theoretical spectrum obtained through density functional theory (DFT) calculations. Na2Ba(NH2)4 complements the range of reported ternary alkali metal alkaline‐earth metal amides with the smallest Shannon radius ratio of rA/AE=0.76. The influence of this ratio on the formation of the new structure type is discussed as well. The characterization of intermediate species such as this ternary amide extends the understanding of the ammonothermal synthesis and can be useful for synthetic control in the formation of nitrides at ammonothermal conditions. [ABSTRACT FROM AUTHOR]

The ternary amide Na2Ba(NH2)4 was synthesized at ammonothermal conditions (870 K, 135 MPa) in custom‐built high‐pressure autoclaves. The compound was structurally characterized using X‐ray diffraction and crystallizes in space group Pccn (no. 56) with lattice parameters a=10.6492(2), b=7.8064(2) and c=8.1046(2) Å. To the best of our knowledge, the structure type has not yet been observed in any ternary amide before and can be described as a defective variant of the NaCl structure type. The presence of amide ions in the compound is verified by Fourier‐transform infrared (FTIR) spectroscopy and the experimental spectrum is compared to the theoretical spectrum obtained through density functional theory (DFT) calculations. Na2Ba(NH2)4 complements the range of reported ternary alkali metal alkaline‐earth metal amides with the smallest Shannon radius ratio of rA/AE=0.76. The influence of this ratio on the formation of the new structure type is discussed as well. The characterization of intermediate species such as this ternary amide extends the understanding of the ammonothermal synthesis and can be useful for synthetic control in the formation of nitrides at ammonothermal conditions. [ABSTRACT FROM AUTHOR]

The imidonitridosilicate Rb3Si6N5(NH)6, being only the second representative of this compound class, was synthesized ammonothermally at 870 K and 230 MPa. Its crystal structure was solved from single‐crystal X‐ray diffraction data. The imidonitridosilicate crystallizes isotypically with the respective potassium compound in space group P4132 with the lattice parameter a=10.9422(4) Å forming a three‐dimensional imidonitridosilicate tetrahedra network with voids for the rubidium ions. The structure model and the presence of the imide groups were verified by Fourier‐Transform infrared (FTIR) and magic‐angle spinning (MAS) NMR spectroscopy, using cross polarization 15N{1H} and 29Si{1H} MAS NMR experiments. Rb3Si6N5(NH)6 represents a possible intermediate during the ammonothermal synthesis of nitridosilicates. The characterization of such intermediates improves the understanding of the reaction pathway from ammonothermal solutions to nitrides. Thus, the ammonothermal synthesis is an alternative approach to the well‐established high‐temperature synthesis leading to the compound class of nitridosilicates. [ABSTRACT FROM AUTHOR]

The imidonitridosilicate Rb3Si6N5(NH)6, being only the second representative of this compound class, was synthesized ammonothermally at 870 K and 230 MPa. Its crystal structure was solved from single‐crystal X‐ray diffraction data. The imidonitridosilicate crystallizes isotypically with the respective potassium compound in space group P4132 with the lattice parameter a=10.9422(4) Å forming a three‐dimensional imidonitridosilicate tetrahedra network with voids for the rubidium ions. The structure model and the presence of the imide groups were verified by Fourier‐Transform infrared (FTIR) and magic‐angle spinning (MAS) NMR spectroscopy, using cross polarization 15N{1H} and 29Si{1H} MAS NMR experiments. Rb3Si6N5(NH)6 represents a possible intermediate during the ammonothermal synthesis of nitridosilicates. The characterization of such intermediates improves the understanding of the reaction pathway from ammonothermal solutions to nitrides. Thus, the ammonothermal synthesis is an alternative approach to the well‐established high‐temperature synthesis leading to the compound class of nitridosilicates. [ABSTRACT FROM AUTHOR]

This study is focused on determining the refractive index as a crucial parameter for evaluating the intrinsic quantum yield and the ligand sensitisation efficiency in solid‐state trivalent lanthanide coordination compounds. For this, eight trivalent europium complexes with phenyl‐terpyridine ([EuX3(ptpy)(L)], X=Cl− or NO3−, ptpy=4′‐phenyl‐2,2′ : 6′,2′′‐terpyridine, L=H2O or other molecules) were examined. Their refractive indices were determined using the Becke lines test by immersing transparent material in a series of media with known refractive indices. Using the set of media presented here, determining crystalline materials′ refractive indices from 1.41 to 1.73 with a step of 0.01 is possible. Assessment of the refractive indices of the complexes mentioned above allowed a comprehensive analysis of their photophysical properties in the solid state. Moreover, this method can be extrapolated for other solid‐state materials, offering valuable insights in the broader field of photophysics. In addition to photoluminescence investigations, the compounds presented were characterised by single‐crystal X‐ray diffraction (SCXRD), powder X‐ray diffraction (PXRD), Hirschfeld surface area analysis, UV‐Vis reflectance spectroscopy, hydrolysis sensitivity analysis, and simultaneous thermogravimetry and differential thermal analysis coupled with mass‐spectrometry (STA‐MS). [ABSTRACT FROM AUTHOR]

The structure of amorphous silicon (a‐Si) is widely thought of as a fourfold‐connected random network, and yet it is defective atoms, with fewer or more than four bonds, that make it particularly interesting. Despite many attempts to explain such "dangling‐bond" and "floating‐bond" defects, respectively, a unified understanding is still missing. Here, we use advanced computational chemistry methods to reveal the complex structural and energetic landscape of defects in a‐Si. We study an ultra‐large‐scale, quantum‐accurate structural model containing a million atoms, and thousands of individual defects, allowing reliable defect‐related statistics to be obtained. We combine structural descriptors and machine‐learned atomic energies to develop a classification of the different types of defects in a‐Si. The results suggest a revision of the established floating‐bond model by showing that fivefold‐bonded atoms in a‐Si exhibit a wide range of local environments–analogous to fivefold centers in coordination chemistry. Furthermore, it is shown that fivefold (but not threefold) coordination defects tend to cluster together. Our study provides new insights into one of the most widely studied amorphous solids, and has general implications for understanding defects in disordered materials beyond silicon alone. [ABSTRACT FROM AUTHOR]

From reactions involving sodium molybdate and dianilines [2,2′-(NH2)C6H4]2(CH2)n (n = 0, 1, 2) and amino-functionalized carboxylic acids 1,2-(NH2)(CO2H)C6H4 or 2-H2NC6H3-1,4-(CO2H)2, in the presence of Et3N and Me3SiCl, products adopting H-bonded networks have been characterized. In particular, the reaction of 2,2′-diaminobiphenyl, [2,2′-NH2(C6H4)]2, and 2-aminoterephthalic acid, H2NC6H3-1,4-(CO2H)2, led to the isolation of [(MoCl3[2,2′-N(C6H4)]2}{HNC6H3-1-(CO2),4-(CO2H)]·2[2,2′-NH2(C6H4)]2·3.5MeCN (1·3.5MeCN), which contains intra-molecular N–H∙∙∙Cl H-bonds and slipped π∙∙∙π interactions. Similar use of 2,2′-methylenedianiline, [2,2′-(NH2)C6H4]2CH2, in combination with 2-aminoterephthalic acid led to the isolation of [MoCl2(O2CC6H3NHCO2SiMe3)(NC6H4CH2C6H4NH2)]·3MeCN (2·3MeCN). Complex 2 contains extensive H-bonds between pairs of centrosymmetrically-related molecules. In the case of 2,2′ethylenedianiline, [2,2′-(NH2)C6H4]2CH2CH2, and anthranilic acid, 1,2-(NH2)(CO2H)C6H4, reaction with Na2MoO4 in the presence of Et3N and Me3SiCl in refluxing 1,2-dimethoxyethane afforded the complex [MoCl3{1,2-(NH)(CO2)C6H4}{NC6H4CH2CH2C6H4NH3}]·MeCN (3·MeCN). In 3, there are intra-molecular bifurcated H-bonds between NH3 H atoms and chlorides, whilst pairs of molecules H-bond further via the NH3 groups to the non-coordinated carboxylate oxygen, resulting in H-bonded chains. Complexes 1 to 3 have been screened for the ring opening polymerization (ROP) of both ε-caprolactone (ε-CL) and δ-valerolactone (δ-VL) using solvent-free conditions under N2 and air. The products were of moderate to high molecular weight, with wide Ð values, and comprised several types of polymer families, including OH-terminated, OBn-terminated (for PCL only), and cyclic polymers. The results of metal-free ROP using the dianilines [2,2′-(NH2)C6H4]2(CH2)n (n = 0, 1, 2) and the amino-functionalized carboxylic acids 1,2-(NH2)(CO2H)C6H4 or 2-H2NC6H3-1,4-(CO2H)2 under similar conditions (no BnOH) are also reported. The dianilines were found to be capable of the ROP of δ-VL (but not ε-CL), whilst anthranilic acid outperformed 2-aminoterephthalic acid for both ε-Cl and δ-VL. [ABSTRACT FROM AUTHOR]

Alkali nitridophosphates AP4N7 and A3P6N11 (A=Na, K, Rb, Cs) have been known for decades. However, their Li homologues have remained elusive. In this work, the highly condensed lithium (imido)nitridophosphates LiP4N7 and Li3−xP6N11−x(NH)x (x=1.66(3)) were synthesized from LiPN2 and P3N5 in the multianvil press at 10 GPa. They constitute the first lithium nitridophosphates with 3D networks exhibiting a degree of condensation larger than 0.5 and high thermal stability. LiP4N7 crystallizes in the orthorhombic space group P212121 with a=4.5846(6) Å, b=8.0094(11) Å, and c=13.252(2) Å (Z=4). Li3−xP6N11−x(NH)x crystallizes in the triclinic space group P1- ${\mathrel{\mathop{{\rm { 1}}}\limits^{{\rm -}}}}$ with Z=2, a=4.6911(11) Å, b=7.024(2) Å, c=12.736(3) Å, α=87.726(11), β=80.279(11), and γ=70.551(12)°. Both compounds are stable against hydrolysis in air. [ABSTRACT FROM AUTHOR]

Alkali nitridophosphates AP4N7 and A3P6N11 (A=Na, K, Rb, Cs) have been known for decades. However, their Li homologues have remained elusive. In this work, the highly condensed lithium (imido)nitridophosphates LiP4N7 and Li3−xP6N11−x(NH)x (x=1.66(3)) were synthesized from LiPN2 and P3N5 in the multianvil press at 10 GPa. They constitute the first lithium nitridophosphates with 3D networks exhibiting a degree of condensation larger than 0.5 and high thermal stability. LiP4N7 crystallizes in the orthorhombic space group P212121 with a=4.5846(6) Å, b=8.0094(11) Å, and c=13.252(2) Å (Z=4). Li3−xP6N11−x(NH)x crystallizes in the triclinic space group P1- ${\mathrel{\mathop{{\rm { 1}}}\limits^{{\rm -}}}}$ with Z=2, a=4.6911(11) Å, b=7.024(2) Å, c=12.736(3) Å, α=87.726(11), β=80.279(11), and γ=70.551(12)°. Both compounds are stable against hydrolysis in air. [ABSTRACT FROM AUTHOR]

Supported metal hydrides are key reactive intermediates in various catalytic processes, such as hydrogenation and dehydrogenation, but are often challenging to characterize spectroscopically. Here, deuterium solid state nuclear magnetic resonance spectroscopy is used to understand the structure of the corresponding silica‐supported zirconium hydrides after H/D exchange as an illustrative example of supported metal hydrides, which have been shown to display notable reactivity towards small molecules (e. g., CO2 and N2O) and to activate both C−H and C−C bonds, hence their use in to the conversion of hydrocarbons (alkanes, polyolefins etc.) [ABSTRACT FROM AUTHOR]

A series of novel and previously published organoantimony compounds (RnSbX3−n, X = Cl, Br; R = o-tolyl, 2,6-xylyl, 1-naphthyl, and 9-anthracenyl), were synthesized and characterized. In addition, single-crystal X-ray diffraction was employed to elucidate the molecular structures of all solid species. These compounds display non-covalent intermolecular interactions in the form of edge-to-face, π···π stacking, and CH3···π interactions, and the effects of the substituent type and substituent bulk on the nature of these interactions present will be highlighted and discussed.

Compounds belonging to the palmierite structure, (Zn3−xMx)A2O8 (M=Co, Ni, Cu and A=V, P) have been prepared employing solid state methods. The transition metal substituted compounds of Zn3V2O8 exhibits colors that are unique varying from mint green to forest green for Co2+ ions. The observed colors were understood based on the allowed d‐d transitions and metal to metal charge transfer (MMCT) transitions. The MMCT transitions involve partially filled d‐orbitals of Co2+ (3d7), Ni2+ (3d8), and Cu2+ (3d9) ions and the V5+ ions (3d0). The spinel compounds, Zn2−xCoxMO4 (M=Ti, Sn) were also prepared to understand the MMCT transitions in the compounds. Band structure calculations were carried out to understand the participating orbitals near the Fermi level and the band gap. The calculations support the idea that the substitution of transition elements in the palmierite structure reduces the overall band gap from 3.18 eV for Zn3V2O8 to 2.61 eV Zn2.5Co0.5V2O8 compound. This indicates the substitution of transition elements provide a tool towards band gap engineering. [ABSTRACT FROM AUTHOR]

In contribution to the pharmaceutical development of cyclic guanosine monophosphorothioate analogue cGMPSA as a potential active pharmaceutical ingredient (API) for the treatment of inherited retinal degenerations (IRDs), its neutral form (cGMPSA‐H) and salts of sodium (‐Na), calcium (‐Ca), ammonium (‐NH4), triethylammonium (‐TEA), tris(hydroxymethyl)aminomethane (‐Tris), benethamine (‐Bnet), and benzathine (‐BZ) were prepared. Their solid‐state properties were studied with differential scanning calorimetry, thermogravimetric analysis, hot‐stage microscopy, and dynamic vapor sorption, and their solubilities were measured in deionized H2O as well as aqueous HCl and NaOH buffers. A total of 21 crystal modifications of cGMPSA were found and characterized by X‐ray powder diffraction. Despite their crystalline character, no API forms featured any observable melting points during thermal analyses and instead underwent exothermic decomposition at ≥163 °C. Both the vapor sorption behavior and solubility were found to differ significantly across the API forms. cGMPSA‐BZ featured the lowest aqueous solubility and hygroscopicity, with 50 μg/mL and 5 % mass gain at maximum relative humidity. The synthesis and crystallization of some crystal modifications were upscaled to >10 g. Single crystal X‐ray diffraction was performed which resulted in the first crystal structure determination and absolute configuration of a cyclic guanosine monophosphorothioate, confirming the RP‐ conformation at the phosphorus atom. [ABSTRACT FROM AUTHOR]

We propose a mechanism for substituent‐responsive reactivities of p‐quinodimethane derivatives with four ester groups through their hierarchical and asymmetric assembly modes. Four asymmetric 7,8,8‐tris(methoxycarbonyl)‐p‐quinodimethanes with a 7‐positioned ethoxycarbonyl (2 a(H)), 2'‐fluoroethoxycarbonyl (2 b(F)), 2'‐chloroethoxycarbonyl (2 c(Cl)), or 2'‐bromoethoxycarbonyl (2 d(Br)) were synthesized and crystallized. 2 a(H), 2 b(F) and 2 d(Br) afforded only one shape crystal, while 2 c(Cl) did two polymorphic 2 c(Cl)‐α and 2 c(Cl)‐β. UV‐irradiation induced topochemical polymerization for 2 a(H), no reactions for 2 b(F) and 2 c(Cl)‐α, and [6+6] photocycloaddition dimerization for 2 c(Cl)‐β and 2 d(Br). Such substituent‐responsive reactivities and crystal structures were compared with those of the known symmetric 7,7,8,8‐tetrakis(alkoxycarbonyl)‐p‐quinodimethanes such as 7,7,8,8‐tetrakis(methoxycarbonyl)‐ (1 a(Me)‐α and 1 a(Me)‐β), 7,7,8,8‐tetrakis(ethoxycarbonyl)‐ (1 b(Et)), and 7,7,8,8‐tetrakis(bromoethoxycarbonyl)‐ (1 c(BrEt)). The comparative study clarified that the reactivities and crystal structures are classified into four types that link to each other. This linkage is understandable when we analyze the crystal structures through the following hierarchical and asymmetric assemblies; conformers, dimers, one dimensional (1D)‐columns, two dimensional (2D)‐sheets, and three dimensional (3D)‐stacked sheets (3D‐crystals). This supramolecular viewpoint is supported by intermolecular interaction energies among neighbored molecules with the density functional theory (DFT) calculation. Such research enables us to elucidate the substituent‐responsive reactivities of the crystals, and reminds us of the selection of the right path in a so‐called "maze game". [ABSTRACT FROM AUTHOR]

The crystalline lithium oxonitridophosphate Li8+xP3O10−xN1+x, was obtained in an ampoule synthesis from P3N5 and Li2O. The compound crystallizes in the triclinic space group P1- ${\mathrel{\mathop{{\rm { 1}}}\limits^{{\rm -}}}}$ with a=5.125(2), b=9.888(5), c=10.217(5) Å, α=70.30(2), β=76.65(2), γ=77.89(2)°. Li8+xP3O10−xN1+x is a double salt, the structure of which contains distinctive complex anion species, namely non‐condensed P(O,N)4 tetrahedra, and P(O,N)7 double tetrahedra connected by one N atom. Additionally, there is mixed occupation of O/N positions, which enables further anionic species by variation of O/N occupancies. To characterize these motifs in detail, complementary analytical methods were applied. The double tetrahedron exhibits significant disorder in single‐crystal X‐ray diffraction. Furthermore, the title compound is a Li+ ion conductor with a total ionic conductivity of 1.2×10−7 S cm−1 at 25 °C, and a corresponding total activation energy of 0.47(2) eV. [ABSTRACT FROM AUTHOR]

In the search for materials for high‐efficiency lighting applications, the color‐point tuning of phosphors for inorganic phosphor converted LEDs (pcLEDs) is of special interest. We expand the recently explored phosphor class of SiBeONs (oxonitridoberyllosilicates) by the synthesis and characterization of SrBe1−xSi2+xO3−2xN2+2x:Eu2+. High temperature synthesis, starting from Sr2N, BeO, SiO2 and Si3N4, yields the target phase as the main product. Upon doping with Eu2+, the pale blue crystals exhibit blue luminescence with emission at 456 nm and a full width at half maximum (fwhm) of 66 nm/3108 cm−1. The structure is an ordered variant of the LaSi3N5 structure type and was elucidated by single‐crystal X‐ray diffraction data. The network in SrBe1−xSi2+xO3−2xN2+2x:Eu2+ is highly condensed with a condensation degree of κ=0.6 comprising corner‐sharing [MX4] (M=Be, Si; X=O, N) tetrahedra, with mixed occupancies on both the ligand and central metal sites. [ABSTRACT FROM AUTHOR]

Abstract In contribution to the pharmaceutical development of cyclic guanosine monophosphorothioate analogue cGMPSA as a potential active pharmaceutical ingredient (API) for the treatment of inherited retinal degenerations (IRDs), its neutral form (cGMPSA‐H) and salts of sodium (‐Na), calcium (‐Ca), ammonium (‐NH4), triethylammonium (‐TEA), tris(hydroxymethyl)aminomethane (‐Tris), benethamine (‐Bnet), and benzathine (‐BZ) were prepared. Their solid‐state properties were studied with differential scanning calorimetry, thermogravimetric analysis, hot‐stage microscopy, and dynamic vapor sorption, and their solubilities were measured in deionized H2O as well as aqueous HCl and NaOH buffers. A total of 21 crystal modifications of cGMPSA were found and characterized by X‐ray powder diffraction. Despite their crystalline character, no API forms featured any observable melting points during thermal analyses and instead underwent exothermic decomposition at ≥163 °C. Both the vapor sorption behavior and solubility were found to differ significantly across the API forms. cGMPSA‐BZ featured the lowest aqueous solubility and hygroscopicity, with 50 μg/mL and 5 % mass gain at maximum relative humidity. The synthesis and crystallization of some crystal modifications were upscaled to >10 g. Single crystal X‐ray diffraction was performed which resulted in the first crystal structure determination and absolute configuration of a cyclic guanosine monophosphorothioate, confirming the RP‐ conformation at the phosphorus atom.

Tetrahedra‐based nitridophosphates show a rich structural chemistry, which can be further extended by incorporating cations in higher coordinated positions, for example, in octahedral voids or by substituting the nitrogen atoms in the network with other anions. Following this approach, SrAl5P4N10O2F3 was synthesized at high‐temperature and high‐pressure conditions using a multianvil press (1400 °C, 5 GPa) starting from Sr(N3)2, c‐PON, P3N5, AlN, and NH4F. SrAl5P4N10O2F3 crystallizes in space group I4‾m2 ${I\bar 4m2}$ with a=11.1685(2) and c=7.84850(10) Å. Atomic‐resolution EDX mapping with scanning transmission electron microscopy (STEM) indicates atom assignments, which are further corroborated by bond‐valence sum (BVS) calculations. Ten Al3+‐centered octahedra form a highly condensed tetra‐face‐capped octahedra‐based unit that is a novel structure motif in network compounds. A network of vertex‐sharing PN4 tetrahedra and chains of face‐sharing Sr2+‐centered cuboctahedra complement the structure. Eu2+‐doped SrAl5P4N10O2F3 shows blue emission (λem=469 nm, fwhm=98 nm; 4504 cm−1) when irradiated with UV light. [ABSTRACT FROM AUTHOR]

Tetrahedra‐based nitridophosphates show a rich structural chemistry, which can be further extended by incorporating cations in higher coordinated positions, for example, in octahedral voids or by substituting the nitrogen atoms in the network with other anions. Following this approach, SrAl5P4N10O2F3 was synthesized at high‐temperature and high‐pressure conditions using a multianvil press (1400 °C, 5 GPa) starting from Sr(N3)2, c‐PON, P3N5, AlN, and NH4F. SrAl5P4N10O2F3 crystallizes in space group I4‾m2 ${I\bar 4m2}$ with a=11.1685(2) and c=7.84850(10) Å. Atomic‐resolution EDX mapping with scanning transmission electron microscopy (STEM) indicates atom assignments, which are further corroborated by bond‐valence sum (BVS) calculations. Ten Al3+‐centered octahedra form a highly condensed tetra‐face‐capped octahedra‐based unit that is a novel structure motif in network compounds. A network of vertex‐sharing PN4 tetrahedra and chains of face‐sharing Sr2+‐centered cuboctahedra complement the structure. Eu2+‐doped SrAl5P4N10O2F3 shows blue emission (λem=469 nm, fwhm=98 nm; 4504 cm−1) when irradiated with UV light. [ABSTRACT FROM AUTHOR]

The Zintl–Klemm idea is a remarkable formalism that can guide us through the crystal structure–electronic structure relationships of solids showing a particular correlation between charge transfers, (8–N) rule and the corresponding structural fragments. Accordingly, this approach has been applied to interpret the relationships between the crystal and electronic structures for numerous intermetallics; yet, are all of these applications of the Zintl–Klemm idea indeed helpful? To answer this question, quantumchemical means were used to explore the electronic structures of three prototypical intermetallics, i.e. LiY2Si2, Sc2Si2Al, and Y2Pd2In. These compounds crystallize with the Mo2FeB2 type of structure whose structure model may be derived from that of the widely encountered U3Si2‐type. The explorations of the electronic structures included examinations of the Mulliken charges, the projected crystal orbital Hamilton populations (pCOHP), the recently introduced crystal orbital bond indices (COBI) and the respective integrated pCOHP as well as COBI values (IpCOHP and ICOBI). The outcome of these investigations indicates that widely diverse types of bonding are evident for the inspected intermetallics so that the predictive power of the Zintl–Klemm idea is limited. [ABSTRACT FROM AUTHOR]

Reported are the synthesis and structural characterization of a series of quaternary lithium-alkaline earth metal alumo-silicides and alumo-germanides with the base formula A2LiAlTt2 (A = Ca, Sr, Ba; Tt = Si, Ge). To synthesize each compound, a mixture of the elements with the desired stoichiometric ratio was loaded into a niobium tube, arc welded shut, enclosed in a silica tube under vacuum, and heated in a tube furnace. Each sample was analyzed by powder and single-crystal X-ray diffraction, and the crystal structure of each compound was confirmed and refined from single-crystal X-ray diffraction data. The structures, despite the identical chemical formulae, are different, largely dependent on the nature of the alkaline earth metal. The differing cation determines the structure type—the calcium compounds are part of the TiNiSi family with the Pnma space group, the strontium compounds are isostructural with Na2LiAlP2 with the Cmce space group, and the barium compounds crystallize with the PbFCl structure type in the P4/nmm space group. The anion (silicon or germanium) only impacts the size of the unit cell, with the silicides having smaller unit cell volumes than the germanides. [ABSTRACT FROM AUTHOR]

Breaking the centrosymmetry of [n]cycloparaphenylenes ([n]CPPs) by one meta connection, leads to bright emission in the typically non‐fluorescent smaller derivatives, conserving their size dependent emissive properties. Using the building block strategy for [n]CPPs, different nitrile substituted meta[n]CPPs (n=6, 8, 10) have been prepared. The nitrile substituent offers a convenient handle for functional group conversions (e.g. carboxylic acid, amide, aldehyde, as well as 1H‐tetrazole). Besides the synthetic work, the photophysical properties of these novel m[n]CPP derivatives have been characterized. Additionally, the host–guest ability of cyano‐m[10]CPP has been explored by studying its complexation with fullerene C60. These insights open new applications of meta[n]CPPs as fluorophore in synthetic organic chemistry, material sciences as well as biomedical research. [ABSTRACT FROM AUTHOR]

Oxonitridophosphates exhibit the potential for broad structural diversity, making them promising host‐compounds in phosphor‐converted light‐emitting diode applications. The novel monophyllo‐oxonitridophosphate β‐MgSrP3N5O2 was obtained by using the high‐pressure multianvil technique. The crystal structure was solved and refined based on single‐crystal X‐ray diffraction data and confirmed by powder X‐ray diffraction. β‐MgSrP3N5O2 crystallizes in the orthorhombic space group Cmme (no. 67, a=8.8109(6), b=12.8096(6), c=4.9065(3) Å, Z=4) and has a structure related to that of Ba2CuSi2O7. DFT calculations were performed to investigate the phase transition from α‐ to β‐MgSrP3N5O2 and to confirm the latter as the corresponding high‐pressure polymorph. Furthermore, the luminescence properties of Eu2+ doped samples of both polymorphs were investigated and discussed, showing blue and cyan emission, respectively (α‐MgSrP3N5O2; λmax=438 nm, fwhm=46 nm/2396 cm−1; β‐MgSrP3N5O2; λmax=502 nm, fwhm=42 nm/1670 cm−1). [ABSTRACT FROM AUTHOR]

Amorphous red phosphorus (a‐P) is one of the remaining puzzling cases in the structural chemistry of the elements. Here, we elucidate the structure, stability, and chemical bonding in a‐P from first principles, combining machine‐learning and density‐functional theory (DFT) methods. We show that a‐P structures exist with a range of energies slightly higher than those of phosphorus nanorods, to which they are closely related, and that the stability of a‐P is linked to the degree of structural relaxation and medium‐range order. We thus complete the stability range of phosphorus allotropes [Angew. Chem. Int. Ed. 2014, 53, 11629] by now including the previously poorly understood amorphous phase, and we quantify the covalent and van der Waals interactions in all main phases of phosphorus. We also study the electronic densities of states, including those of hydrogenated a‐P. Beyond the present study, our structural models are expected to enable wider‐ranging first‐principles investigations—for example, of a‐P‐based battery materials. [ABSTRACT FROM AUTHOR]

Unsymmetrical gold(III)‐dithiolene complexes are potential candidates for molecular materials that exhibit thermal structural phase transitions. In this study, unsymmetrical ppy‐gold(III) (ppy−=C‐deprotonated‐2‐phenylpyridine(−)) complexes [AuC5] and [AuC6] coordinated by dithiolene ligands containing tetrathiafulvalene (TTF) skeletons with pentylthio (2‐{bis(pentylthio)‐1,3‐dithiol‐2‐ylidene}‐1,3‐dithiol‐4,5‐dithiolate(2−)) and hexylthio groups (2‐{bis(hexylthio)‐1,3‐dithiol‐2‐ylidene}‐1,3‐dithiol‐4,5‐dithiolate(2−)) were synthesized. Both complexes exhibited a large absorption band at approximately 508 nm, owing to intramolecular ligand‐to‐ligand charge transfer. One‐dimensional columnar structures with head‐to‐tail molecular arrangements around the metal ions were constructed in the crystals. The flexible alkylthio groups were intercalated into crystalline spaces between dithiolene ligands in the columns. [AuC5] exhibits a simple phase transition at 198 °C between crystalline and isotropic phases irreversibly. The crystalline phase of [AuC6] observed at 25 °C melted at 148 °C. Another crystalline phase grew above 148 °C with a very slow crystallization rate from the liquid phase and was completely transformed into an isotropic phase at 200 °C. [ABSTRACT FROM AUTHOR]

All‐solid‐state batteries with solid ionic conductors packed between solid electrode films can release the dead space between them, enabling a greater number of cells to stack, generating higher voltage to the pack. This Review is focused on using high‐voltage cathode materials, in which the redox peak of the components is extended beyond 4.7 V. Li−Ni−Mn−O systems are currently under investigation for use as the cathode in high‐voltage cells. Solid electrolytes compatible with the cathode, including halide‐ and sulfide‐based electrolytes, are also reviewed. Discussion extends to the compatibility between electrodes and electrolytes at such extended potentials. Moreover, control over the thickness of the anode is essential to reduce solid‐electrolyte interphase formation and growth of dendrites. The Review discusses routes toward optimization of the cell components to minimize electrode‐electrolyte impedance and facilitate ion transportation during the battery cycle. [ABSTRACT FROM AUTHOR]

The correlation of the electrocatalytic activity with electrical conductivity, oxygen-vacancies, and electronegativity have been studied in a series of isostructural oxides, having the so-called Ruddlesden-Popper structure. The structures of these materials comprise transition metals that are octahedrally coordinated to form a network of bilayer stacks. These materials are catalytically active for both half-reactions of water-splitting, namely oxygen-evolution reaction (OER) and hydrogen-evolution reaction (HER). They show a systematic increase in electrocatalytic activity in progression from Sr3Ti2O7 to Sr3TiMnO7, Sr3TiFeO7−δ, and Sr3TiCoO7−δ. The kinetic studies using the Tafel method indicate the same trend across the series, where the best catalyst also has the fastest kinetics for both HER and OER. In addition, the same progression is observed in the concentration of oxygen-vacancies, as well as the electrical conductivity in a wide range of temperatures, 25 °C–800 °C. The material that shows the best electrocatalytic activity, i.e., Sr3TiCoO7−δ, also has the highest electrical conductivity and the greatest concentration of oxygen vacancies in the series. The correlations observed in this work indicate that trends in electrocatalytic performance may be related to the systematic increase in electrical conductivity, electronegativity, and oxygen-vacancies, as well as the electron occupancy of eg orbitals, which can affect the strength of sigma interactions between the catalyst and reaction intermediates. [ABSTRACT FROM AUTHOR]

Phenomena such as anticooperativity and competition among non‐covalent bond donors and acceptors are key considerations when exploring the polymorphic and stoichiomorphic landscapes of binary and higher‐order cocrystalline architectures. We describe the preparation of four cocrystals of 1,3,5‐trifluoro‐2,4,6‐triiodobenzene with N‐heterocyclic compounds, namely acridine, 3‐aminopyridine, 4‐methylaminopyridine, and 1,2‐di(4‐pyridyl)ethane. The cocrystals, which are characterized by single‐crystal and powder X‐ray diffraction experiments, all show moderately strong and directional iodine⋅⋅⋅nitrogen halogen bonds with reduced distance parameters ranging from 0.79 to 0.92 and carbon‐iodine⋅⋅⋅nitrogen bond angles ranging from 165.4(3) to 175.31(7)°. The cocrystal comprising 1,3,5‐trifluoro‐2,4,6‐triiodobenzene and acridine provides a relatively rare example where all three halogen bond donor sites form halogen bonds with three acceptor molecules, overcoming an anticooperative effect. This effect manifests itself through the lengthening of non‐halogen‐bonded C−I bonds, weakening their potential to form halogen bonds. The effect is only observed once two halogen bonds have been formed to 1,3,5‐trifluoro‐2,4,6‐triiodobenzene; one such bond does not appear to be adequate. Among the four cocrystals studied, competition between the pyridyl nitrogen atoms and the amine nitrogen atoms suggests that the former are the preferred halogen bond acceptors. Analysis by Hirshfeld fingerprint plots and 13C and 19F magic‐angle spinning solid‐state nuclear magnetic resonance (NMR) spectroscopy provides additional insights into the prevalence of various short contacts in the crystal structures and into the spectral response to halogen‐bond‐induced cocrystallization. [ABSTRACT FROM AUTHOR]

We report a series of Zn(II) and Cd(II) metal complexes [L12(ZnCl2)] (1), [L12(ZnBr2)] (2), [L12(CdCl2)] (3), [L12(CdI2)] (4), [L22(ZnCl2)] (5), [L22(ZnBr2)] (6), [L22(ZnI2)] (7), [L22(CdCl2)] (8), [L32(CdCl2)] (9) and [L42(ZnBr2)] (10), synthesized using various unsymmetrical aryl thiourea ligands: 1‐(2,6‐diisopropylphenyl)‐3‐phenylthiourea (L1), 1‐mesityl‐3‐phenylthiourea (L2), 1‐(2‐fluorophenyl)‐3‐phenylthiourea (L3) and symmetrical 1,3‐bis(2‐fluorophenyl)thiourea (L4). The ligands and metal complexes were characterized by 1H, 13C{1H} NMR, FT‐IR analysis. Solid‐state structures of the zinc and cadmium metal complexes (1–8) were established using the single‐crystal diffraction analysis technique. Furthermore, the catalytic activities of the Zn(II) complexes towards hydroboration of aldehydes and ketones (‐C=O) as substrates were studied. Excellent yields of the corresponding boronate esters were achieved. [ABSTRACT FROM AUTHOR]

Herein, the effect of structure on pseudocapacitive properties in alkaline conditions is demonstrated through the investigation of isoelectronic oxides Ca2LaMn2O7 and Sr2LaMn2O7, where the difference in ionic radii of Ca2+ and Sr2+ leads to a change in structure and lattice symmetry, resulting in an orthorhombic Cmcm structure for the former and a tetragonal I4/mmm structure for the latter. While calcium and strontium do not make a direct contribution to the near‐surface faradaic processes that are essential to the pseudocapacitive properties, their effect on the structure leads to a change in the oxygen intercalation process and the associated pseudocapacitive energy storage. It is shown that Sr2LaMn2O7 has a significantly greater specific capacitance than Ca2LaMn2O7. In addition, the former shows a considerably higher‐energy density compared to the latter. Furthermore, these materials show highly stable energy‐storage properties, and retain their specific capacitance over 10 000 cycles of charge–discharge in a symmetric pseudocapacitive cell. Importantly, these findings show the structure–property relationships, where a change in the structure and lattice symmetry can result in a significant change in pseudocapacitive charge–discharge properties in isoelectronic systems. [ABSTRACT FROM AUTHOR]

The resolution of proton solid‐state NMR spectra is usually limited by broadening arising from dipolar interactions between spins. Magic‐angle spinning alleviates this broadening by inducing coherent averaging. However, even the highest spinning rates experimentally accessible today are not able to completely remove dipolar interactions. Here, we introduce a deep learning approach to determine pure isotropic proton spectra from a two‐dimensional set of magic‐angle spinning spectra acquired at different spinning rates. Applying the model to 8 organic solids yields high‐resolution 1H solid‐state NMR spectra with isotropic linewidths in the 50–400 Hz range. [ABSTRACT FROM AUTHOR]

Non‐crystalline lithium oxonitridophosphate (LiPON) is used as solid electrolyte in all‐solid‐state batteries. Crystalline lithium oxonitridophosphates are important model structures to retrieve analytical information that can be used to understand amorphous phases better. The new crystalline lithium oxonitridophosphate Li5+xP2O6−xN1+x was synthesized as an off‐white powder by ampoule synthesis at 750–800 °C under Ar atmosphere. It crystallizes in the monoclinic space group P21/c with a=15.13087(11) Å, b=9.70682(9) Å, c=8.88681(7) Å, and β=106.8653(8)°. Two P(O,N)4 tetrahedra connected by an N atom form the structural motif [P2O6−xN1+x](5+x)−. The structure was elucidated from X‐ray diffraction data and the model corroborated by NMR and infrared spectroscopy, and elemental analyses. Measurements of ionic conductivity show a total ionic conductivity of 6.8×10−7 S cm−1 at 75 °C with an activation energy of 0.52±0.01 eV. [ABSTRACT FROM AUTHOR]

Owing to their widespread properties, nitridophosphates are of high interest in current research. Explorative high‐pressure high‐temperature investigations yielded various compounds with stoichiometry MP2N4 (M=Be, Ca, Sr, Ba, Mn, Cd), which are discussed as ultra‐hard or luminescent materials, when doped with Eu2+. Herein, we report the first germanium nitridophosphate, GeP2N4, synthesized from Ge3N4 and P3N5 at 6 GPa and 800 °C. The structure was determined by single‐crystal X‐ray diffraction and further characterized by energy‐dispersive X‐ray spectroscopy, density functional theory calculations, IR and NMR spectroscopy. The highly condensed network of PN4‐tetrahedra shows a strong structural divergence to other MP2N4 compounds, which is attributed to the stereochemical influence of the lone pair of Ge2+. Thus, the formal exchange of alkaline earth cations with Ge2+ may open access to various compounds with literature‐known stoichiometry, however, new structures and properties. [ABSTRACT FROM AUTHOR]

Despite decades of research on various carbamates and their important applications, only one aluminum N,N‐dialkylcarbamate (ADC) with an aluminum:carbamate ratio of 1 : 3 has been structurally described and comprehensively studied so far, namely tris(diisopropyl)carbamate. The reasons for this situation include problems with the used synthetic routes. The process of CO2 insertion into Al−N bonds of tris(dialkylamido)alanes resolved these difficulties. Using this advantageous synthetic route, the dimethyl and diethyl, as well as the pyrrolidino, piperidino, and N‐methylpiperazino derivatives were now successfully prepared. These ADCs were investigated by solid‐state NMR spectroscopy, where line‐shape analyses of the 27Al NMR spectra allowed conclusions with respect to the determination of the quadrupole coupling parameters. Furthermore, data of an intermediate during the CO2 insertion into tris(diisopropylamido)alane were obtained by in‐situ IR spectroscopy, which were complemented by NMR measurements of samples periodically taken during the reaction. Partial hydrolysis of tris(pyrrolidino)carbamate revealed a complex Al3(μ3‐O) cluster structure, which was elucidated by single crystal X‐ray diffraction. [ABSTRACT FROM AUTHOR]

The structure of the inclusion compound of 1‐(3‐hydroxy‐4‐{(E)‐[(2‐hydroxyphenyl)methylidene]amino}phenyl)ethan‐1‐one – a light‐sensitive guest molecule, with 4,4′‐cyclohexylidenebisphenol as light‐stable host molecule was studied at 293 and 200 K. At room temperature the crystal structure may be described in space group P‐1, with one of the two guest molecules disordered occupying a crystallographic inversion center or in space group P1, avoiding the need for disorder description. One of the ordered guest molecules is connected by H‐bonds to a water molecule and a host molecule. The other guest molecule has the role of filling space. The distinction between the structures in the two space groups is discussed from a crystallographic and from chemical interactions point of view. The crystal structure at low temperature justifies the chemical arguments regarding the true space group. [ABSTRACT FROM AUTHOR]

In this contribution, we describe a set of three chlorinated bridged ethers with varying numbers of sulfur and oxygen atoms. The substitution leads to highly emissive compounds with tunable photophysical properties in relationship to their state of aggregation, i. e. in solution, as aggregates and in the solid state. Additionally, an in‐depth X‐ray diffractometric analysis supported by a Hirshfeld study of non‐covalent interactions and quantum chemical simulations was carried out. As the outcome, it was found that the content of sulfur in the compounds regulates the tuning of emission in solution as well as in the aggregated states as a consequence of their variation of planarity. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms that connect heat and electron transport with crystal structures and defect chemistry is fundamental to develop materials with thermoelectric properties. In this work, we synthesized a series of self‐doped compounds Cu2+xMn1−xGeS4 through Cu for Mn substitution. Using a combination of powder X‐ray diffraction, high resolution transmission electron microscopy and precession‐assisted electron diffraction tomography, we evidence that the materials are composed of interconnected enargite‐ and stannite‐type structures, via the formation of nanodomains with a high density of coherent interfaces. By combining experiments with ab initio electron and phonon calculations, we discuss the structure–thermoelectric properties relationships and clarify the interesting crystal chemistry in this system. We demonstrate that excess Cu+ substituted for Mn2+ dopes holes into the top of the valence band, leading to a remarkable enhancement of the power factor and figure of merit ZT. [ABSTRACT FROM AUTHOR]

The metathesis reaction of aryltellurium chloride, ppyTeCl [ppy=2‐(2'‐pyridyl)phenyl] (5) with AgClO4 afforded Intramolecular Chalcogen Bonding (IChB)‐stabilized organotellurenyl cation [ppyTe] ⋅ ClO4 ([6] ⋅ ClO4). The reaction of [6] ⋅ ClO4 with K2PtCl4 in acetic acid resulted in the formation of platinum(II)‐based carboxylate‐bridged heterobimetallic complex [Pt(ppyTe)(μ‐OOCMe)Cl2], 7 containing an organotellurenyl cation as ligand. This is the first time a Pt(II) complex of an organotellurenyl cation donor‐acceptor ligand has been reported. Complex 7 was characterized by multi‐nuclear NMR spectroscopy (1H, 13C, and 125Te), FT‐IR spectroscopy, CHN analysis, and single‐crystal X‐ray diffraction studies. The single‐crystal X‐ray diffraction studies and DFT analysis infer that the Te center in 7 behaves as an ambiphilic ligand, accepting electrons from the N‐atom of the ppy moiety and the O‐atom of the carboxylate groups while simultaneously donating electrons to the Pt(II) center. The 2D‐fingerprint plots derived from the Hirshfeld surface analysis reveal multiple intermolecular interactions in the packing diagrams of complex 7. The natural charges accumulated on the atoms in complex 7 were calculated by Natural Population Analysis (NPA). In addition, the HOMO‐LUMO energy gap in 7 was calculated. [ABSTRACT FROM AUTHOR]