Chalcogen Chemistry: Fundamentals and Applications. Edited by Vito Lippolis, Claudio Santi, Eder J. Lenardão and Antonio L. Braga. Royal Society of Chemistry, 2023. Hardcover, pp. 728. Price EUR 156.00. ISBN 978-1-83916-422-4
铜绿化学：基础和应用。编辑:Vito Lippolis, Claudio Santi, Eder J. lenardao和Antonio L. Braga。皇家化学学会，2023。精装本，第728页。价格156.00欧元。ISBN 978-1-83916-422-4
{"title":"<b>Chalcogen Chemistry: Fundamentals and Applications</b>. Edited by Vito Lippolis, Claudio Santi, Eder J. Lenardão and Antonio L. Braga. Royal Society of Chemistry, 2023. Hardcover, pp. 728. Price EUR 156.00. ISBN 978-1-83916-422-4","authors":"Marc Fourmigué","doi":"10.1107/s2052520623007771","DOIUrl":"https://doi.org/10.1107/s2052520623007771","url":null,"abstract":"Chalcogen Chemistry: Fundamentals and Applications. Edited by Vito Lippolis, Claudio Santi, Eder J. Lenardão and Antonio L. Braga. Royal Society of Chemistry, 2023. Hardcover, pp. 728. Price EUR 156.00. ISBN 978-1-83916-422-4","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135886150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Solar thermochemical hydrogen production (STCH) via redox-active metal oxides is an approach for direct solar-driven hydrogen generation typically using a high-temperature redox cycle involving refractory oxides and steam. Typical cycles involve high-temperature reduction of oxides to form oxygen vacancies, followed by lower temperature reaction between oxygen vacancies and steam where the oxide is re-oxidized and the steam is reduced to hydrogen. Only a few materials have demonstrated reversible cycling under the typically harsh STCH conditions (e.g. 1500°C reduction, 900°C re-oxidation) and critical questions remain on the true reversibility of non-stoichiometric multi-cation oxide systems, significantly hampered by the lack of single-phase samples for these material systems. To date, most STCH processes have relied on CeO2 as a benchmark active material, but more recently, the 12R phase of BaCe0.25Mn0.75O3 (BCM) has demonstrated greater hydrogen-generation potential at lower peak temperatures. However, previous reports of 12R-BCM have included large fractions, > 10 wt%, of secondary phases, which complicate analysis of the stability and performance. A comprehensive understanding of the redox mechanism and reversibility of the process in BCM can only be achieved with nearly single-phase samples which, to date, have been difficult to produce. Here two approaches to BCM synthesis are reported: solid state and sol–gel-based routes. It is demonstrated that both routes can be tuned to produce the 12R structure with > 97 wt% yield when annealed ≥1450°C. Herein synchrotron-based diffraction measurements of rhombohedral 12R-BCM enabled characterization of the anisotropy between thermal expansion along the c-axis and within the ab plane. The impact of high-temperature redox cycling on the stability and phase fraction of the 12R-BCM polytype was also investigated. These results offer two viable routes for synthesis of high-purity 12R-BCM critically needed for evaluating the efficacy of BCM as a STCH material and validate its ability to split water at lower temperatures over extended numbers of redox cycles.
{"title":"Synthesis and structure of high-purity BaCe0.25Mn0.75O3: an improved material for thermochemical water splitting","authors":"Robert T. Bell, Nicholas A. Strange, Dan A. Plattenberger, S. Shulda, J. Park, A. Ambrosini, K. Heinselman, Josh Sugar, P. Parilla, E. Coker, A. McDaniel, D. Ginley","doi":"10.1107/s2052520622010393","DOIUrl":"https://doi.org/10.1107/s2052520622010393","url":null,"abstract":"Solar thermochemical hydrogen production (STCH) via redox-active metal oxides is an approach for direct solar-driven hydrogen generation typically using a high-temperature redox cycle involving refractory oxides and steam. Typical cycles involve high-temperature reduction of oxides to form oxygen vacancies, followed by lower temperature reaction between oxygen vacancies and steam where the oxide is re-oxidized and the steam is reduced to hydrogen. Only a few materials have demonstrated reversible cycling under the typically harsh STCH conditions (e.g. 1500°C reduction, 900°C re-oxidation) and critical questions remain on the true reversibility of non-stoichiometric multi-cation oxide systems, significantly hampered by the lack of single-phase samples for these material systems. To date, most STCH processes have relied on CeO2 as a benchmark active material, but more recently, the 12R phase of BaCe0.25Mn0.75O3 (BCM) has demonstrated greater hydrogen-generation potential at lower peak temperatures. However, previous reports of 12R-BCM have included large fractions, > 10 wt%, of secondary phases, which complicate analysis of the stability and performance. A comprehensive understanding of the redox mechanism and reversibility of the process in BCM can only be achieved with nearly single-phase samples which, to date, have been difficult to produce. Here two approaches to BCM synthesis are reported: solid state and sol–gel-based routes. It is demonstrated that both routes can be tuned to produce the 12R structure with > 97 wt% yield when annealed ≥1450°C. Herein synchrotron-based diffraction measurements of rhombohedral 12R-BCM enabled characterization of the anisotropy between thermal expansion along the c-axis and within the ab plane. The impact of high-temperature redox cycling on the stability and phase fraction of the 12R-BCM polytype was also investigated. These results offer two viable routes for synthesis of high-purity 12R-BCM critically needed for evaluating the efficacy of BCM as a STCH material and validate its ability to split water at lower temperatures over extended numbers of redox cycles.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79334854","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Cocrystallization is a promising method for generating new energetic materials with improved performances. Herein, a novel energetic cocrystal composed of 1H-tetrazole/sodium perchlorate was prepared using the solvent evaporation method. This cocrystal is characterized as containing organic azole derivatives and an ionic perchlorate salt, which is used as an oxidizer in pyrotechnics. The crystal structure was determined via single-crystal X-ray diffraction. The as-prepared crystal exhibited a lamellar structure consisting of 1H-tetrazole and sodium perchlorate layers. A molecular structure comparison between the cocrystal and pristine ingredients revealed variations in the bond lengths and angles owing to the cocrystallization. The hydrogen bond formed by adjacent tetrazole rings was strengthened. The 1H-tetrazole/sodium perchlorate cocrystal was structurally compared with crystals previously reported to the Cambridge Structural Database including sodium perchlorate in lamellar structures. The lamellar structure of the cocrystal exhibited weak layer-to-layer interactions compared with those of the other crystals. Fourier transform infrared and Raman spectroscopy analyses were conducted, and the relationship between the spectroscopy results and the crystal/molecular structure are discussed. The results of the spectroscopic analyses exhibited peak shifts that indicate structural changes in bond lengths and angles owing to the cocrystallization.
{"title":"Preparation and crystallographic characterization of 1H-tetrazole/NaClO4 energetic cocrystal","authors":"Kazuki Inoue, S. Matsumoto, M. Kumasaki","doi":"10.1107/s2052520622010204","DOIUrl":"https://doi.org/10.1107/s2052520622010204","url":null,"abstract":"Cocrystallization is a promising method for generating new energetic materials with improved performances. Herein, a novel energetic cocrystal composed of 1H-tetrazole/sodium perchlorate was prepared using the solvent evaporation method. This cocrystal is characterized as containing organic azole derivatives and an ionic perchlorate salt, which is used as an oxidizer in pyrotechnics. The crystal structure was determined via single-crystal X-ray diffraction. The as-prepared crystal exhibited a lamellar structure consisting of 1H-tetrazole and sodium perchlorate layers. A molecular structure comparison between the cocrystal and pristine ingredients revealed variations in the bond lengths and angles owing to the cocrystallization. The hydrogen bond formed by adjacent tetrazole rings was strengthened. The 1H-tetrazole/sodium perchlorate cocrystal was structurally compared with crystals previously reported to the Cambridge Structural Database including sodium perchlorate in lamellar structures. The lamellar structure of the cocrystal exhibited weak layer-to-layer interactions compared with those of the other crystals. Fourier transform infrared and Raman spectroscopy analyses were conducted, and the relationship between the spectroscopy results and the crystal/molecular structure are discussed. The results of the spectroscopic analyses exhibited peak shifts that indicate structural changes in bond lengths and angles owing to the cocrystallization.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87865128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Preferences for formation and competition between halogen⋯halogen and halogen⋯H contacts have been studied for model compounds of monohalogenated ethanes.
对于单卤代乙烷的模型化合物，已经研究了卤素和卤素⋯H接触之间形成和竞争的偏好。
{"title":"Evolution of intermolecular contacts with temperature and pressure in bromoethane and iodoethane – a comparative study","authors":"M. Bujak, A. Olejniczak, M. Podsiadło","doi":"10.1107/S2052520622010149","DOIUrl":"https://doi.org/10.1107/S2052520622010149","url":null,"abstract":"Preferences for formation and competition between halogen⋯halogen and halogen⋯H contacts have been studied for model compounds of monohalogenated ethanes.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"29 1","pages":"868 - 875"},"PeriodicalIF":0.0,"publicationDate":"2022-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81603009","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Eight cocrystals featuring an isoniazid derivative are synthesized and characterized. Most of the cocrystals show great similarity in hydrogen bonding between each other with only a few exceptions.
合成并表征了八个具有异烟肼衍生物的共晶。除少数例外，大多数共晶之间的氢键有很大的相似性。
{"title":"Design of a series of cocrystals featuring isoniazid modified with diacetone alcohol","authors":"M. Scheepers, A. Lemmerer","doi":"10.1107/S2052520622009532","DOIUrl":"https://doi.org/10.1107/S2052520622009532","url":null,"abstract":"Eight cocrystals featuring an isoniazid derivative are synthesized and characterized. Most of the cocrystals show great similarity in hydrogen bonding between each other with only a few exceptions.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"1953 1","pages":"857 - 867"},"PeriodicalIF":0.0,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87768741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The synthesis and the structural characterization of a new dinuclear platinum(III) complex are presented. Lantern-shaped platinum(III) complexes have been shown to have antitumor activity, so this new complex should be screened through antitumor screening tests.
{"title":"Synthesis and structural characterization of a new dinuclear platinum(III) complex, [Pt2Cl4(NH3)2{μ-HN=C(O)But}2]","authors":"D. Vinci, D. Chateigner","doi":"10.1107/S2052520622009660","DOIUrl":"https://doi.org/10.1107/S2052520622009660","url":null,"abstract":"The synthesis and the structural characterization of a new dinuclear platinum(III) complex are presented. Lantern-shaped platinum(III) complexes have been shown to have antitumor activity, so this new complex should be screened through antitumor screening tests.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"112 1","pages":"835 - 841"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81183549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A triple salt of decavanadate, V10O28 6−, containing mixed organic guanylurea (diaminomethylideneurea cation, HGU+) and metforminium(2+) (H2Met2+) cations and hydronium (H3O+) cations, has been synthesized by heating metformin hydrochloride, picolinic acid, and sodium metavanadate in aqueous solution at pH 4 and 333 K followed by maintaining the solution at 300 K overnight to give an orange crystalline product. As commonly observed, the V10O28 6− anion lies on an inversion center. Charge is balanced by two H2Met2+ dications and two monocations, one HGU+ and one H3O+, substitutionally disordered about another inversion center. The HGU+ cation is further positionally disordered by rotation of 26.3 (4)° about an axis approximately along the direction of the three essentially collinear N atoms of the cation, thereby hydrogen bonding to two adjacent rows of cluster O atoms running diagonally across the equatorial plane of the V10O28 6− anion. The highly concerted nature of the HGU+...cluster interaction in each orientation suggests a synthon that likely preexisted in solution and perhaps, along with heat, contributes to the degradation of the metformin to HGU+. The structure of the salt exhibits a complex charge-stabilized hydrogen-bonded network involving extended C 4 4(8) chains of the water molecules and the H2Met2+ cations linking the chains into two-dimensional sheets parallel to the bc plane, and V10O28 6− anions linking those sheets into a three-dimensional structure through Ow—H...O, N—H...O and C—H...O intermolecular interactions. The disordered HGU+ cation and the H3O+ cation occupy spaces with excess volume in the three-dimensional network structure.
{"title":"Four-position disorder of cationic protonated guanylurea in a stable three-dimensional network in the structure of a triple salt decavanadate complex (HGU+)(H2Met2+)2(H3O+)(V10O28\u0000 6−)·8H2O","authors":"Aungkana Chatkon, Joseph P. Haller, K. Haller","doi":"10.1107/s2052520622008915","DOIUrl":"https://doi.org/10.1107/s2052520622008915","url":null,"abstract":"A triple salt of decavanadate, V10O28\u0000 6−, containing mixed organic guanylurea (diaminomethylideneurea cation, HGU+) and metforminium(2+) (H2Met2+) cations and hydronium (H3O+) cations, has been synthesized by heating metformin hydrochloride, picolinic acid, and sodium metavanadate in aqueous solution at pH 4 and 333 K followed by maintaining the solution at 300 K overnight to give an orange crystalline product. As commonly observed, the V10O28\u0000 6− anion lies on an inversion center. Charge is balanced by two H2Met2+ dications and two monocations, one HGU+ and one H3O+, substitutionally disordered about another inversion center. The HGU+ cation is further positionally disordered by rotation of 26.3 (4)° about an axis approximately along the direction of the three essentially collinear N atoms of the cation, thereby hydrogen bonding to two adjacent rows of cluster O atoms running diagonally across the equatorial plane of the V10O28\u0000 6− anion. The highly concerted nature of the HGU+...cluster interaction in each orientation suggests a synthon that likely preexisted in solution and perhaps, along with heat, contributes to the degradation of the metformin to HGU+. The structure of the salt exhibits a complex charge-stabilized hydrogen-bonded network involving extended C\u0000 4\u0000 4(8) chains of the water molecules and the H2Met2+ cations linking the chains into two-dimensional sheets parallel to the bc plane, and V10O28\u0000 6− anions linking those sheets into a three-dimensional structure through Ow—H...O, N—H...O and C—H...O intermolecular interactions. The disordered HGU+ cation and the H3O+ cation occupy spaces with excess volume in the three-dimensional network structure.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84914388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pseudoatom databanks, collections of parameters from the multipole model of electron densities for various atom types, are used to replace the Independent Atom Model with the more accurate Transferable Aspherical Atom Model (TAAM) in crystal structure refinements. The databanks are also employed to reconstruct the electron density of a molecule, crystal or biomacromolecular complex in a fast yet accurate way and compute various properties such as the energy of electrostatic interactions, for example. A even faster but similarly accurate model for estimations of electrostatic energy exists called aug-PROmol [Bojarowski, Kumar & Dominiak (2016). ChemPhysChem, 17, 2455–2460]. A model analogous to aug-PROmol cannot be built from the current pseudoatom databanks, as they perform badly when truncated to the monopole level. Here, new strategies for multipole model refinements were sought, leading to better parametrization at the monopole level. This would allow the creation of a pseudoatom databank in a single route of model parametrization, which would be suitable for both crystal structure refinement and rapid electrostatic energy calculations. Here it is shown that the cumulative approach to multipole model refinements, as opposed to simultaneous or iterative refinements of all multipole model parameters (Pv , κ, Plm , κ′), leads to substantially different models of electron density. Cumulative refinement of two blocks of parameters, the first with Pv and κ and then the second with Plm and κ′, leads to the P v κ|P lm κ′ model having promising properties. The P v κ|P lm κ′ model is as good as the University at Buffalo DataBank (UBDB) in X-ray structure TAAM refinements and electrostatic energy estimations, especially for less polar molecules. When truncated to the monopole level, the P v κ model has a chance to replace aug-PROmol in fast yet accurate electrostatics energy calculations, although some improvements in κ parametrization for polar functional groups are still needed. The P v κ model is also a source of point charges which behave similarly to restrained electrostatic potential (RESP) charges in electrostatic interaction energy estimations.
{"title":"New refinement strategies for a pseudoatom databank – toward rapid electrostatic interaction energy estimations","authors":"S. Bojarowski, B. Gruza, D. Trzybiński, R. Kamiński, A. Hoser, Prashant Kumar, K. Woźniak, P. Dominiak","doi":"10.1107/s2052520622008800","DOIUrl":"https://doi.org/10.1107/s2052520622008800","url":null,"abstract":"Pseudoatom databanks, collections of parameters from the multipole model of electron densities for various atom types, are used to replace the Independent Atom Model with the more accurate Transferable Aspherical Atom Model (TAAM) in crystal structure refinements. The databanks are also employed to reconstruct the electron density of a molecule, crystal or biomacromolecular complex in a fast yet accurate way and compute various properties such as the energy of electrostatic interactions, for example. A even faster but similarly accurate model for estimations of electrostatic energy exists called aug-PROmol [Bojarowski, Kumar & Dominiak (2016). ChemPhysChem, 17, 2455–2460]. A model analogous to aug-PROmol cannot be built from the current pseudoatom databanks, as they perform badly when truncated to the monopole level. Here, new strategies for multipole model refinements were sought, leading to better parametrization at the monopole level. This would allow the creation of a pseudoatom databank in a single route of model parametrization, which would be suitable for both crystal structure refinement and rapid electrostatic energy calculations. Here it is shown that the cumulative approach to multipole model refinements, as opposed to simultaneous or iterative refinements of all multipole model parameters (Pv\u0000 , κ, Plm\u0000 , κ′), leads to substantially different models of electron density. Cumulative refinement of two blocks of parameters, the first with Pv\u0000 and κ and then the second with Plm\u0000 and κ′, leads to the P\u0000 \u0000 v\u0000 κ|P\u0000 \u0000 lm\u0000 κ′ model having promising properties. The P\u0000 \u0000 v\u0000 κ|P\u0000 \u0000 lm\u0000 κ′ model is as good as the University at Buffalo DataBank (UBDB) in X-ray structure TAAM refinements and electrostatic energy estimations, especially for less polar molecules. When truncated to the monopole level, the P\u0000 \u0000 v\u0000 κ model has a chance to replace aug-PROmol in fast yet accurate electrostatics energy calculations, although some improvements in κ parametrization for polar functional groups are still needed. The P\u0000 \u0000 v\u0000 κ model is also a source of point charges which behave similarly to restrained electrostatic potential (RESP) charges in electrostatic interaction energy estimations.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88475812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The discovery of a new quaternary intermetallic compound of composition Zr3Mn3Sn4Ga during a survey of the Zr–Mn–Sn–Ga phase diagram is reported. Single-crystal X-ray diffraction reveals that the new compound crystallizes in a hexagonal lattice (space group P63/mmc, No. 194). The analysis of single-crystal X-ray diffraction data indicates that the atomic arrangement is an ordered variant of the high-temperature hexagonal Ti6Sn5 crystal structure. From a simple geometry point of view, the unit cell consists of GaZr3 octahedra chains and Mn chains growing along the sixfold symmetry axis c. The Mn chains are stacked within the ab basal plane in a kagome geometry, with large interatomic distances. The possible slight levels of Sn/Ga and Zr/Mn mixed occupancy based on additional results of electron probe microanalysis and single-crystal neutron diffraction are discussed. It is noteworthy that this compound is the first quaternary intermetallic discovered in this structure and the first Ti6Sn5 derivative bearing a magnetic metal, namely Mn, in the 6g position, which may give rise to interesting physical properties.
{"title":"Zr3Mn3Sn4Ga: a new hexagonal Ti6Sn5-type quaternary intermetallic","authors":"Thomas Clausse, L. Diop, N. Martin, R. Sibille, T. Mazet","doi":"10.1107/s2052520622009453","DOIUrl":"https://doi.org/10.1107/s2052520622009453","url":null,"abstract":"The discovery of a new quaternary intermetallic compound of composition Zr3Mn3Sn4Ga during a survey of the Zr–Mn–Sn–Ga phase diagram is reported. Single-crystal X-ray diffraction reveals that the new compound crystallizes in a hexagonal lattice (space group P63/mmc, No. 194). The analysis of single-crystal X-ray diffraction data indicates that the atomic arrangement is an ordered variant of the high-temperature hexagonal Ti6Sn5 crystal structure. From a simple geometry point of view, the unit cell consists of GaZr3 octahedra chains and Mn chains growing along the sixfold symmetry axis c. The Mn chains are stacked within the ab basal plane in a kagome geometry, with large interatomic distances. The possible slight levels of Sn/Ga and Zr/Mn mixed occupancy based on additional results of electron probe microanalysis and single-crystal neutron diffraction are discussed. It is noteworthy that this compound is the first quaternary intermetallic discovered in this structure and the first Ti6Sn5 derivative bearing a magnetic metal, namely Mn, in the 6g position, which may give rise to interesting physical properties.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84057685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work is devoted to an investigation of elemental composition, crystal structure and thermal expansion of natural oxoborate azoproite from the Tazheran massif (Siberia, Russia) in the temperature range 5–1650 K. Elemental composition was determined by energy-dispersive X-ray spectroscopy (EDX). Its empirical formula based on five oxygen atoms is (Mg1.81Fe2+ 0.19)∑2.00(Fe3+ 0.36Ti0.26Mg0.26Al0.12)∑1.00O2(BO3). Local environment, oxidation states and ratio of Fe atoms are determined using Mössbauer spectroscopy and compared with EDX and single-crystal X-ray diffraction (SCXRD) data. A refinement of the crystal structure from SCXRD data collected at 293 K was provided for the first time. The structure could be described both in terms of cation- and anion-centered polyhedra. It is composed of vertex- and edge-sharing metal–oxygen [MO6] n − octahedra that form extended zigzag chains along the a axis building up a framework with the [BO3]3− triangles located in its distorted trigonal channels. From the other point of view, there are double chains consisting of oxocentred [OM 4] n + tetrahedra and [OM 5] n + tetragonal pyramids forming six-membered rings with the triangles in its cavities. Four non-equivalent Mn + sites are occupied by cations as follows: M(1) (2a) and M(2) (2d) – Mg, M(3) (4g) – Mg and Fe2+, M(4) (4h) – Fe3+, Ti4+, Mg and Al3+. According to differential scanning calorimetry, low- and high-temperature powder X-ray diffraction (LT- and HT-XRD) data, Mössbauer spectroscopy and magnetometry data (5 ≤ T ≤ 1650 K), there are no phase transitions obtained in the temperature range investigated. However, some anomalies in temperature dependencies of unit-cell parameters caused by a partial Fe2+ → Fe3+ oxidation are found in the range 873–1173 K. Azoproite melts at a temperature higher than 1600 K. Eigenvalues of the thermal expansion tensor are calculated for the oxoborate and thermal expansion is described in comparison with its crystal structure.
{"title":"X-ray diffraction and Mössbauer spectroscopy study of oxoborate azoproite (Mg,Fe2+)2(Fe3+,Ti,Mg,Al)O2(BO3): an in situ temperature-dependent investigation (5 ≤ T ≤ 1650 K)","authors":"Y. Biryukov, A. Zinnatullin, Irina O. Levashova, A. Shablinskii, M. Cherosov, R. Bubnova, F. Vagizov, M. Krzhizhanovskaya, S. Filatov, V. Shilovskikh, I. Pekov","doi":"10.1107/s2052520622009349","DOIUrl":"https://doi.org/10.1107/s2052520622009349","url":null,"abstract":"This work is devoted to an investigation of elemental composition, crystal structure and thermal expansion of natural oxoborate azoproite from the Tazheran massif (Siberia, Russia) in the temperature range 5–1650 K. Elemental composition was determined by energy-dispersive X-ray spectroscopy (EDX). Its empirical formula based on five oxygen atoms is (Mg1.81Fe2+\u0000 0.19)∑2.00(Fe3+\u0000 0.36Ti0.26Mg0.26Al0.12)∑1.00O2(BO3). Local environment, oxidation states and ratio of Fe atoms are determined using Mössbauer spectroscopy and compared with EDX and single-crystal X-ray diffraction (SCXRD) data. A refinement of the crystal structure from SCXRD data collected at 293 K was provided for the first time. The structure could be described both in terms of cation- and anion-centered polyhedra. It is composed of vertex- and edge-sharing metal–oxygen [MO6]\u0000 n\u0000 \u0000 − octahedra that form extended zigzag chains along the a axis building up a framework with the [BO3]3− triangles located in its distorted trigonal channels. From the other point of view, there are double chains consisting of oxocentred [OM\u0000 4]\u0000 n\u0000 \u0000 + tetrahedra and [OM\u0000 5]\u0000 n\u0000 \u0000 + tetragonal pyramids forming six-membered rings with the triangles in its cavities. Four non-equivalent Mn\u0000 \u0000 + sites are occupied by cations as follows: M(1) (2a) and M(2) (2d) – Mg, M(3) (4g) – Mg and Fe2+, M(4) (4h) – Fe3+, Ti4+, Mg and Al3+. According to differential scanning calorimetry, low- and high-temperature powder X-ray diffraction (LT- and HT-XRD) data, Mössbauer spectroscopy and magnetometry data (5 ≤ T ≤ 1650 K), there are no phase transitions obtained in the temperature range investigated. However, some anomalies in temperature dependencies of unit-cell parameters caused by a partial Fe2+ → Fe3+ oxidation are found in the range 873–1173 K. Azoproite melts at a temperature higher than 1600 K. Eigenvalues of the thermal expansion tensor are calculated for the oxoborate and thermal expansion is described in comparison with its crystal structure.","PeriodicalId":7080,"journal":{"name":"Acta Crystallographica Section B Structural Science, Crystal Engineering and Materials","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82701478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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