Pub Date : 2024-04-12DOI: 10.1107/s2053229624002973
Roman Pacholski, Krzysztof Durka, Piotr Buchalski
Typically reactions of N-heterocyclic carbenes with transition metals are straightforward and require a carbene salt, a base strong enough to deprotonate such a salt and a metal. Yet when carbene precursors are in the form of triazolium salts, reaction may not proceed as easily as expected. In our work, we intended to obtain a triazolylidene complex of iron(II) chloride, but due to the presence of small amounts of water in the tetrahydrofuran solvent used, bis(acetonitrile)tetrakis(1-benzyl-1H-1,2,4-triazole-κN4)iron(II) μ-oxido-bis[trichloridoferrate(III)] acetonitrile disolvate, [Fe(C9H9N3)4(CH3CN)2][Fe2Cl6O]·2CH3CN – an interesting anion with a linear geometry of the O atom – was formed instead of the iron carbene complex. Reaction proceeded via cleavage of the alkyl N-substituent of the triazolium salt. The formation of the product was confirmed by X-ray crystallography. The crystal structure and possible reaction pathways are discussed.
通常情况下，N-杂环碳烯与过渡金属的反应非常简单，需要碳烯盐、足以使碳烯盐去质子化的碱和金属。然而，当碳烯前体是三唑盐形式时，反应可能不会像预期的那样容易进行。在我们的工作中，我们本想获得氯化铁（II）的三唑亚基络合物，但由于所使用的四氢呋喃溶剂中含有少量的水，双（乙腈）四（1-苄基-1H-1,2、4-triazole-κN4)iron(II) μ-oxido-bis[trichloridoferrate(III)] acetonitrile disolvate，[Fe(C9H9N3)4(CH3CN)2][Fe2Cl6O]-2CH3CN--一种 O 原子呈线性几何形状的有趣阴离子--取代了碳化铁络合物。反应是通过裂解三唑盐的烷基 N 取代基进行的。X 射线晶体学证实了产物的形成。本文讨论了晶体结构和可能的反应途径。
{"title":"Synthesis and crystal structure of an iron triazole complex resulting from the unexpected ligand cleavage of a triazolium carbene precursor","authors":"Roman Pacholski, Krzysztof Durka, Piotr Buchalski","doi":"10.1107/s2053229624002973","DOIUrl":"https://doi.org/10.1107/s2053229624002973","url":null,"abstract":"Typically reactions of N-heterocyclic carbenes with transition metals are straightforward and require a carbene salt, a base strong enough to deprotonate such a salt and a metal. Yet when carbene precursors are in the form of triazolium salts, reaction may not proceed as easily as expected. In our work, we intended to obtain a triazolylidene complex of iron(II) chloride, but due to the presence of small amounts of water in the tetrahydrofuran solvent used, bis(acetonitrile)tetrakis(1-benzyl-1<i>H</i>-1,2,4-triazole-κ<i>N</i><sup>4</sup>)iron(II) μ-oxido-bis[trichloridoferrate(III)] acetonitrile disolvate, [Fe(C<sub>9</sub>H<sub>9</sub>N<sub>3</sub>)<sub>4</sub>(CH<sub>3</sub>CN)<sub>2</sub>][Fe<sub>2</sub>Cl<sub>6</sub>O]·2CH<sub>3</sub>CN – an interesting anion with a linear geometry of the O atom – was formed instead of the iron carbene complex. Reaction proceeded <i>via</i> cleavage of the alkyl N-substituent of the triazolium salt. The formation of the product was confirmed by X-ray crystallography. The crystal structure and possible reaction pathways are discussed.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140576744","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}
Pub Date : 2024-04-10DOI: 10.1107/s2053229624003061
Decato, D., Palatinus, L., Stierle, A., Stierle, D.
{"title":"Absolute structure determination of Berkecoumarin by X-ray and electron diffraction","authors":"Decato, D., Palatinus, L., Stierle, A., Stierle, D.","doi":"10.1107/s2053229624003061","DOIUrl":"https://doi.org/10.1107/s2053229624003061","url":null,"abstract":"","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140576627","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}
Acridines are a class of bioactive agents which exhibit high biological stability and the ability to intercalate with DNA; they have a wide range of applications. Pyridine derivatives have a wide range of biological activities. To enhance the properties of acridine and 2-amino-3-methylpyridine as the active pharmaceutical ingredient (API), 4-nitrobenzoic acid was chosen as a coformer. In the present study, a mixture of acridine and 4-nitrobenzoic acid forms the salt acridinium 4-nitrobenzoate, C13H10N+·C7H4NO4− (I), whereas a mixture of 2-amino-3-methylpyridine and 4-nitrobenzoic acid forms the salt 2-amino-3-methylpyridinium 4-nitrobenzoate, C6H9N2+·C7H4NO4− (II). In both salts, protonation takes place at the ring N atom. The crystal structure of both salts is predominantly governed by hydrogen-bond interactions. In salt I, C—H…O and N—H…O interactions form an infinite chain in the crystal, whereas in salt II, intermolecular N—H…O interactions form an eight-membered R22(8) ring motif. A theoretical charge–density analysis reveals the charge–density distribution of the inter- and intramolecular interactions of both salts. An in-silico ADME analysis predicts the druglikeness properties of both salts and the results confirm that both salts are potential drug candidates with good bioavailability scores and there is no violation of the Lipinski rules, which supports the druglikeness properties of both salts. However, although both salts exhibit drug-like properties, salt I has higher gastrointestinal absorption than salt II and hence it may be considered a potential drug candidate.
吖啶是一类生物活性剂，具有很高的生物稳定性和与 DNA 交互作用的能力，应用范围十分广泛。吡啶衍生物具有广泛的生物活性。为了增强吖啶和 2-氨基-3-甲基吡啶作为活性药物成分（API）的特性，我们选择了 4-硝基苯甲酸作为共聚物。在本研究中，吖啶和 4-硝基苯甲酸的混合物形成 4-硝基苯甲酸吖啶鎓盐，C13H10N+-C7H4NO4-（I），而 2-氨基-3-甲基吡啶和 4-硝基苯甲酸的混合物形成 4-硝基苯甲酸 2-氨基-3-甲基吡啶鎓盐，C6H9N2+-C7H4NO4-（II）。在这两种盐中，质子化都发生在环 N 原子上。这两种盐的晶体结构主要受氢键相互作用的支配。在盐 I 中，C-H...O 和 N-H...O 相互作用在晶体中形成一条无限链，而在盐 II 中，分子间 N-H...O 相互作用形成一个八元 R22(8) 环图案。理论电荷密度分析揭示了这两种盐的分子间和分子内相互作用的电荷密度分布。结果证实，这两种盐都是潜在的候选药物，具有良好的生物利用度，而且没有违反 Lipinski 规则，这支持了这两种盐的药物亲和性。不过，虽然两种盐都具有类药物特性，但盐 I 的胃肠道吸收率高于盐 II，因此可被视为潜在的候选药物。
{"title":"Crystal structure, intermolecular interactions, charge–density distribution and ADME properties of the acridinium 4-nitrobenzoate and 2-amino-3-methylpyridinium 4-nitrobenzoate salts: a combined experimental and theoretical study","authors":"Hemalatha Balasubramanian, Petchi Raman Mariappan, Kumaradhas Poomani","doi":"10.1107/s2053229624002250","DOIUrl":"https://doi.org/10.1107/s2053229624002250","url":null,"abstract":"Acridines are a class of bioactive agents which exhibit high biological stability and the ability to intercalate with DNA; they have a wide range of applications. Pyridine derivatives have a wide range of biological activities. To enhance the properties of acridine and 2-amino-3-methylpyridine as the active pharmaceutical ingredient (API), 4-nitrobenzoic acid was chosen as a coformer. In the present study, a mixture of acridine and 4-nitrobenzoic acid forms the salt acridinium 4-nitrobenzoate, C<sub>13</sub>H<sub>10</sub>N<sup>+</sup>·C<sub>7</sub>H<sub>4</sub>NO<sub>4</sub><sup>−</sup> (<b>I</b>), whereas a mixture of 2-amino-3-methylpyridine and 4-nitrobenzoic acid forms the salt 2-amino-3-methylpyridinium 4-nitrobenzoate, C<sub>6</sub>H<sub>9</sub>N<sub>2</sub><sup>+</sup>·C<sub>7</sub>H<sub>4</sub>NO<sub>4</sub><sup>−</sup> (<b>II</b>). In both salts, protonation takes place at the ring N atom. The crystal structure of both salts is predominantly governed by hydrogen-bond interactions. In salt <b>I</b>, C—H…O and N—H…O interactions form an infinite chain in the crystal, whereas in salt <b>II</b>, intermolecular N—H…O interactions form an eight-membered <i>R</i><sub>2</sub><sup>2</sup>(8) ring motif. A theoretical charge–density analysis reveals the charge–density distribution of the inter- and intramolecular interactions of both salts. An <i>in-silico</i> ADME analysis predicts the druglikeness properties of both salts and the results confirm that both salts are potential drug candidates with good bioavailability scores and there is no violation of the Lipinski rules, which supports the druglikeness properties of both salts. However, although both salts exhibit drug-like properties, salt <b>I</b> has higher gastrointestinal absorption than salt <b>II</b> and hence it may be considered a potential drug candidate.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140168705","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}
Pub Date : 2024-02-26DOI: 10.1107/s2053229624001621
Zane S. Dash, Raymond Q. Huang, Ana N. Kimber, Opeyemi T. Olubajo, Mark Polk, Oliver P. Rancu, Lauren L. Zhang, Jane Fu, Nejc Nagelj, Kristopher G. Reynolds, Shao-Liang Zheng, Dilek K. Dogutan
The compound [5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrinato]platinum(II), [Pt(C52H40F4N4)] or Pt(II)TFP, has been synthesized and structurally characterized by single-crystal X-ray crystallography. The Pt porphyrin exhibits a long-lived phosphorescent excited state (τ0 = 66 µs), which has been characterized by transient absorption and emission spectroscopy. The phosphorescence is extremely sensitive to oxygen, as reflected by a quenching rate constant of 5.0 × 108M−1 s−1, and as measured by Stern–Volmer quenching analysis.
{"title":"Oxygen quenching of structurally characterized [5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrinato]platinum(II)","authors":"Zane S. Dash, Raymond Q. Huang, Ana N. Kimber, Opeyemi T. Olubajo, Mark Polk, Oliver P. Rancu, Lauren L. Zhang, Jane Fu, Nejc Nagelj, Kristopher G. Reynolds, Shao-Liang Zheng, Dilek K. Dogutan","doi":"10.1107/s2053229624001621","DOIUrl":"https://doi.org/10.1107/s2053229624001621","url":null,"abstract":"The compound [5,10,15,20-tetrakis(4-fluoro-2,6-dimethylphenyl)porphyrinato]platinum(II), [Pt(C<sub>52</sub>H<sub>40</sub>F<sub>4</sub>N<sub>4</sub>)] or Pt(II)TFP, has been synthesized and structurally characterized by single-crystal X-ray crystallography. The Pt porphyrin exhibits a long-lived phosphorescent excited state (τ<sub>0</sub> = 66 µs), which has been characterized by transient absorption and emission spectroscopy. The phosphorescence is extremely sensitive to oxygen, as reflected by a quenching rate constant of 5.0 × 10<sup>8</sup> <i>M</i><sup>−1</sup> s<sup>−1</sup>, and as measured by Stern–Volmer quenching analysis.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139968153","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}
Pub Date : 2024-01-31DOI: 10.1107/s205322962400010x
Ke Yang, Yuting Yang, Ziqin Yao, Sisi Cheng, Xue Cui, Xingyi Wang, Yi Han, Feiyan Yi, Guang Mo
We prepared a 3d–4f heterobimetallic CuEu–organic framework NBU-8 with a density of 1921 kg m−3 belonging to the family of dense packing materials (dense metal–organic frameworks or MOFs). This MOF material was prepared from 4-(pyrimidin-5-yl)benzoic acid (HPBA) with a bifunctional ligand site as a tripodal ligand and Cu2+ and Eu3+ as the metal centres; the molecular formula is Cu3Eu2(PBA)6(NO3)6·H2O. This material is a very promising dimethylformamide (DMF) molecular chemical sensor. Systematic high-pressure studies of NBU-8 were carried out by powder X-ray diffraction, high-pressure X-ray diffraction and molecular dynamics simulation. The high-pressure experiment shows that the (006) diffraction peak of the crystal structure moves toward a low angle with increasing pressure, accompanied by the phenomenon that the d-spacing increases, and as the pressure increases, the (10) diffraction peak moves to a higher angle, the amplitude of the d-spacing is significantly reduced and finally merges with the (006) diffraction peak into one peak. The amplitude of the d-spacing is significantly reduced, indicating that NBU-8 compresses and deforms along the a-axis direction when subjected to uniform pressure. This is caused by tilting of the ligands to become more vertical along the c direction, leading to its expansion. This allows greater contraction along the a direction. We also carried out a Rietveld structure refinement and a Birch–Murnaghan solid-state equation fitting for the high-pressure experimental results. We calculated the bulk modulus of the material to be 45.68 GPa, which is consistent with the calculated results. The framework is among the most rigid MOFs reported to date, exceeding that of Cu–BTC. Molecular dynamics simulations estimated that the mechanical energy absorbed by the system when pressurized to 5.128 GPa was 249.261 kcal mol−1. The present work will provide fresh ideas for the study of mechanical energy in other materials.
我们制备了一种 3d-4f 异双金属 CuEu 有机框架 NBU-8，其密度为 1921 kg m-3，属于致密堆积材料（致密金属有机框架或 MOF）家族。这种 MOF 材料由 4-(嘧啶-5-基)苯甲酸（HPBA）制备而成，双功能配体位点为三足配体，Cu2+ 和 Eu3+ 为金属中心；分子式为 Cu3Eu2(PBA)6(NO3)6-H2O。这种材料是一种非常有前途的二甲基甲酰胺（DMF）分子化学传感器。通过粉末 X 射线衍射、高压 X 射线衍射和分子动力学模拟对 NBU-8 进行了系统的高压研究。高压实验表明，随着压力的增加，晶体结构的（006）衍射峰向低角度移动，同时伴随着d-间距增大的现象，随着压力的增加，（10）衍射峰向高角度移动，d-间距的振幅明显减小，最后与（006）衍射峰合并成一个峰。d 距的振幅明显减小，表明 NBU-8 在受到均匀压力时沿 a 轴方向压缩变形。这是由于配体沿 c 轴方向倾斜，变得更加垂直，从而导致其膨胀。这使得沿 a 轴方向的收缩更大。我们还对高压实验结果进行了里特维尔德结构细化和 Birch-Murnaghan 固态方程拟合。我们计算出该材料的体积模量为 45.68 GPa，这与计算结果一致。该框架是迄今为止所报道的刚度最高的 MOFs 之一，超过了 Cu-BTC。分子动力学模拟估计，当压力达到 5.128 GPa 时，系统吸收的机械能为 249.261 kcal mol-1。这项工作将为研究其他材料的机械能提供新的思路。
{"title":"High-pressure study of a 3d–4f heterometallic CuEu–organic skeleton","authors":"Ke Yang, Yuting Yang, Ziqin Yao, Sisi Cheng, Xue Cui, Xingyi Wang, Yi Han, Feiyan Yi, Guang Mo","doi":"10.1107/s205322962400010x","DOIUrl":"https://doi.org/10.1107/s205322962400010x","url":null,"abstract":"We prepared a 3<i>d</i>–4<i>f</i> heterobimetallic CuEu–organic framework NBU-8 with a density of 1921 kg m<sup>−3</sup> belonging to the family of dense packing materials (dense metal–organic frameworks or MOFs). This MOF material was prepared from 4-(pyrimidin-5-yl)benzoic acid (HPBA) with a bifunctional ligand site as a tripodal ligand and Cu<sup>2+</sup> and Eu<sup>3+</sup> as the metal centres; the molecular formula is Cu<sub>3</sub>Eu<sub>2</sub>(PBA)<sub>6</sub>(NO<sub>3</sub>)<sub>6</sub>·H<sub>2</sub>O. This material is a very promising dimethylformamide (DMF) molecular chemical sensor. Systematic high-pressure studies of NBU-8 were carried out by powder X-ray diffraction, high-pressure X-ray diffraction and molecular dynamics simulation. The high-pressure experiment shows that the (006) diffraction peak of the crystal structure moves toward a low angle with increasing pressure, accompanied by the phenomenon that the <i>d</i>-spacing increases, and as the pressure increases, the (10<img alt=\"overline{2}\" loading=\"lazy\" src=\"/cms/asset/d522fc89-d7d8-43e4-9908-cf95004ca08d/ayc2oc3022-gra-0001.png\"/>) diffraction peak moves to a higher angle, the amplitude of the <i>d</i>-spacing is significantly reduced and finally merges with the (006) diffraction peak into one peak. The amplitude of the <i>d</i>-spacing is significantly reduced, indicating that NBU-8 compresses and deforms along the <i>a</i>-axis direction when subjected to uniform pressure. This is caused by tilting of the ligands to become more vertical along the <i>c</i> direction, leading to its expansion. This allows greater contraction along the <i>a</i> direction. We also carried out a Rietveld structure refinement and a Birch–Murnaghan solid-state equation fitting for the high-pressure experimental results. We calculated the bulk modulus of the material to be 45.68 GPa, which is consistent with the calculated results. The framework is among the most rigid MOFs reported to date, exceeding that of Cu–BTC. Molecular dynamics simulations estimated that the mechanical energy absorbed by the system when pressurized to 5.128 GPa was 249.261 kcal mol<sup>−1</sup>. The present work will provide fresh ideas for the study of mechanical energy in other materials.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139670084","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}
Pub Date : 2024-01-04DOI: 10.1107/s2053229623010781
J. Alejandro Savin, C. Gabriela Ávila-Ortíz, Marco Antonio Leyva-Ramírez, Eusebio Juaristi
The synthesis of a chiral isothiourea, namely, (4aR,8aR)-3-phenyl-4a,5,6,7,8,8a-hexahydrobenzo[4,5]imidazo[2,1-b]thiazol-9-ium bromide, C15H17N2S+·Br−, with potential organocatalytic and anti-inflammatory activity is reported. The preparation of the heterocycle of interest was carried out in two high-yielding steps. The hydrobromide salt of the isothiourea of interest provided suitable crystals for X-ray diffraction analysis, the results of which are reported. Salient observations from this analysis are the near perpendicular arrangement of the phenyl ring and the mean plane of the heterocycle. This conformational characteristic may be relevant with regard the stereoselectivity induced by the chiral isothiourea in asymmetric reactions. Furthermore, evidence was found for the existence of an S…Br− halogen bond.
报告了一种手性异硫脲的合成，即 (4aR,8aR)-3-苯基-4a,5,6,7,8,8a-六氢苯并[4,5]咪唑并[2,1-b]噻唑-9-溴化铵（C15H17N2S+-Br-），它具有潜在的有机催化和抗炎活性。相关杂环的制备分两个高产步骤进行。相关异硫脲的氢溴酸盐为 X 射线衍射分析提供了合适的晶体，报告了分析结果。从分析中观察到的显著特点是苯基环的排列与杂环的平均平面近乎垂直。这一构象特征可能与手性异硫脲在不对称反应中诱导的立体选择性有关。此外，还发现了 S...Br- 卤素键存在的证据。
{"title":"X-ray crystallographic structure of a novel enantiopure chiral isothiourea with potential applications in enantioselective synthesis","authors":"J. Alejandro Savin, C. Gabriela Ávila-Ortíz, Marco Antonio Leyva-Ramírez, Eusebio Juaristi","doi":"10.1107/s2053229623010781","DOIUrl":"https://doi.org/10.1107/s2053229623010781","url":null,"abstract":"The synthesis of a chiral isothiourea, namely, (4a<i>R</i>,8a<i>R</i>)-3-phenyl-4a,5,6,7,8,8a-hexahydrobenzo[4,5]imidazo[2,1-<i>b</i>]thiazol-9-ium bromide, C<sub>15</sub>H<sub>17</sub>N<sub>2</sub>S<sup>+</sup>·Br<sup>−</sup>, with potential organocatalytic and anti-inflammatory activity is reported. The preparation of the heterocycle of interest was carried out in two high-yielding steps. The hydrobromide salt of the isothiourea of interest provided suitable crystals for X-ray diffraction analysis, the results of which are reported. Salient observations from this analysis are the near perpendicular arrangement of the phenyl ring and the mean plane of the heterocycle. This conformational characteristic may be relevant with regard the stereoselectivity induced by the chiral isothiourea in asymmetric reactions. Furthermore, evidence was found for the existence of an S…Br<sup>−</sup> halogen bond.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139096628","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}
Pub Date : 2024-01-01DOI: 10.1107/s2053229623011099
Sweta Yadav, Jai Prakash
We report the structural characterization of a new quaternary telluride, Ba2Y0.87(1)Mn1.71(1)Te5, which was synthesized by the direct reaction of the elements inside a vacuum-sealed fused-silica tube. The quaternary phase is the first member of the Ba–M–Mn–Te system (M = Sc and Y). The composition and structure of the phase were elucidated using SEM–EDX (scanning electron microscopy–energy dispersive X-ray spectrometry) and single-crystal X-ray diffraction (SCXRD) studies. The title phase is nonstoichiometric and crystallizes in the monoclinic system (space group C2/m) having the refined unit-cell parameters a = 15.1466 (8), b = 4.5782 (3), c = 10.6060 (7) Å and β = 116.956 (2)°, with two formula units (Z = 2). The pseudo-two-dimensional crystal structure of Ba2Y0.87(1)Mn1.71(1)Te5 consists of distorted YTe6 octahedra and MnTe4 tetrahedra as the building blocks of the structure. The YTe6 octahedra are arranged to form infinite one-dimensional chains by sharing edges along the [010] direction. These chains are further connected to the MnTe4 tetrahedra along the c axis to create layered two-dimensional polyanionic [Y0.87(1)Mn1.71(1)Te5]4− units. The stuffing of Ba2+ cations in between the layers of [Y0.87(1)Mn1.71(1)Te5]4− anions brings the charge neutrality of the structure. Each Ba atom in the structure sits at the centre of a distorted monocapped trigonal prism-like polyhedron of seven Te atoms.
我们报告了一种新的四价碲化物 Ba2Y0.87(1)Mn1.71(1)Te5 的结构特征，它是在真空密封的熔融石英管内通过元素直接反应合成的。该四元相是 Ba-Mn-Te 体系（M = Sc 和 Y）的第一个成员。利用 SEM-EDX（扫描电子显微镜-能量色散 X 射线光谱法）和单晶 X 射线衍射（SCXRD）研究阐明了该相的组成和结构。该化合物为非共沸物，在单斜晶系（空间群为 C2/m）中结晶，其细化单胞参数为 a = 15.1466 (8)、b = 4.5782 (3)、c = 10.6060 (7) Å 和 β = 116.956 (2)°，具有两个公式单元 (Z = 2)。Ba2Y0.87(1)Mn1.71(1)Te5 的伪二维晶体结构由扭曲的 YTe6 八面体和 MnTe4 四面体构成。YTe6 八面体沿[010]方向共边排列，形成无限的一维链。这些链沿着 c 轴与 MnTe4 四面体进一步连接，形成层状二维多阴离子[Y0.87(1)Mn1.71(1)Te5]4-单元。在[Y0.87(1)Mn1.71(1)Te5]4-阴离子层之间塞入 Ba2+ 阳离子，使该结构的电荷趋于中性。结构中的每个 Ba 原子都位于由 7 个 Te 原子组成的扭曲单帽三棱柱多面体的中心。
{"title":"Synthesis and crystal structure of Ba2Y0.87(1)Mn1.71(1)Te5","authors":"Sweta Yadav, Jai Prakash","doi":"10.1107/s2053229623011099","DOIUrl":"https://doi.org/10.1107/s2053229623011099","url":null,"abstract":"We report the structural characterization of a new quaternary telluride, Ba<sub>2</sub>Y<sub>0.87(1)</sub>Mn<sub>1.71(1)</sub>Te<sub>5</sub>, which was synthesized by the direct reaction of the elements inside a vacuum-sealed fused-silica tube. The quaternary phase is the first member of the Ba–<i>M</i>–Mn–Te system (<i>M</i> = Sc and Y). The composition and structure of the phase were elucidated using SEM–EDX (scanning electron microscopy–energy dispersive X-ray spectrometry) and single-crystal X-ray diffraction (SCXRD) studies. The title phase is nonstoichiometric and crystallizes in the monoclinic system (space group <i>C</i>2/<i>m</i>) having the refined unit-cell parameters <i>a</i> = 15.1466 (8), <i>b</i> = 4.5782 (3), <i>c</i> = 10.6060 (7) Å and β = 116.956 (2)°, with two formula units (<i>Z</i> = 2). The pseudo-two-dimensional crystal structure of Ba<sub>2</sub>Y<sub>0.87(1)</sub>Mn<sub>1.71(1)</sub>Te<sub>5</sub> consists of distorted YTe<sub>6</sub> octahedra and MnTe<sub>4</sub> tetrahedra as the building blocks of the structure. The YTe<sub>6</sub> octahedra are arranged to form infinite one-dimensional chains by sharing edges along the [010] direction. These chains are further connected to the MnTe<sub>4</sub> tetrahedra along the <i>c</i> axis to create layered two-dimensional polyanionic [Y<sub>0.87(1)</sub>Mn<sub>1.71(1)</sub>Te<sub>5</sub>]<sup>4−</sup> units. The stuffing of Ba<sup>2+</sup> cations in between the layers of [Y<sub>0.87(1)</sub>Mn<sub>1.71(1)</sub>Te<sub>5</sub>]<sup>4−</sup> anions brings the charge neutrality of the structure. Each Ba atom in the structure sits at the centre of a distorted monocapped trigonal prism-like polyhedron of seven Te atoms.","PeriodicalId":510890,"journal":{"name":"Acta Crystallographica Section C","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139072454","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}
) diffraction peak moves to a higher angle, the amplitude of the d-spacing is significantly reduced and finally merges with the (006) diffraction peak into one peak. The amplitude of the d-spacing is significantly reduced, indicating that NBU-8 compresses and deforms along the a-axis direction when subjected to uniform pressure. This is caused by tilting of the ligands to become more vertical along the c direction, leading to its expansion. This allows greater contraction along the a direction. We also carried out a Rietveld structure refinement and a Birch–Murnaghan solid-state equation fitting for the high-pressure experimental results. We calculated the bulk modulus of the material to be 45.68 GPa, which is consistent with the calculated results. The framework is among the most rigid MOFs reported to date, exceeding that of Cu–BTC. Molecular dynamics simulations estimated that the mechanical energy absorbed by the system when pressurized to 5.128 GPa was 249.261 kcal mol−1. The present work will provide fresh ideas for the study of mechanical energy in other materials.
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