Pub Date : 2022-01-01DOI: 10.4236/csta.2022.112002
B. Ouni, T. Larbi, M. Amlouk
{"title":"Vibrational, Electronic and Structural Study of Sprayed ZnO Thin Film Based on the IR-Raman Spectra and DFT Calculations","authors":"B. Ouni, T. Larbi, M. Amlouk","doi":"10.4236/csta.2022.112002","DOIUrl":"https://doi.org/10.4236/csta.2022.112002","url":null,"abstract":"","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70482892","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 : 2022-01-01DOI: 10.4236/csta.2022.111001
Dikima D. Bibelayi, Albert S. Lundemba, P. V. Tsalu, Pitchouna I. Kilunga, J. Tshishimbi, Zéphirin G. Yav
Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R 1 ,R 2 ,-C=Se, R 1 ,R 2 ,-C=S and R 1 ,R 2 ,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around −0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF 3 . Besides hydrogen bonds,
{"title":"Hydrogen Bonds of C=S, C=Se and C=Te with C-H in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)","authors":"Dikima D. Bibelayi, Albert S. Lundemba, P. V. Tsalu, Pitchouna I. Kilunga, J. Tshishimbi, Zéphirin G. Yav","doi":"10.4236/csta.2022.111001","DOIUrl":"https://doi.org/10.4236/csta.2022.111001","url":null,"abstract":"Considerable interest in hydrogen bonding involving chalcogen has been growing since the IUPAC committee has redefined hydrogen bonding. Not only the focus is on unconventional acceptors, but also on donors not discussed before. It has been mentioned in previous studies that the proton of the H-C group could be involved in hydrogen bonding, but with conventional acceptors. In this study, we explored the ability of hydrogen bond formation of Se, S and Te acceptors with the H-C donor using Cambridge Structural Database in conjunction with Ab Initio calculations. In the CSD, there are respectively 256, 6249 and 11 R 1 ,R 2 ,-C=Se, R 1 ,R 2 ,-C=S and R 1 ,R 2 ,-C=Te structures that form hydrogen bonds, in which the N,N groups are majority. Except for C=S acceptor which can form a hydrogen bond with its C, C group, both C=Se and C=Te acceptors could form a hydrogen bond only with N,C and N,N groups. CSD analysis shows very similar d (norm) around −0.04 Å, while DFT-calculated interaction for N,C and N,N groups are also similar. Both interaction distances derived from CSD analysis and DFT-calculated interaction energies demonstrate that the acceptors form stable complexes with H-CF 3 . Besides hydrogen bonds,","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70482837","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 : 2021-08-30DOI: 10.4236/csta.2021.103004
V. Hariharan, Jignesh Vanjaria, A. Arjunan, G. Tompa, Hongbin Yu
In the past studies have shown that the addition of Ge and Sn into Si lattice to form SiGeSn enhances its carrier mobility and band-gap properties. Conventionally SiGeSn epitaxial films are grown using Ultra-High Vacuum (UHV) conditions with pressures ranging from 10-8 torr to 10-10 torr which makes high volume manufacturing very expensive. On the contrary, the use of low-pressure CVD processes (vacuum levels of 10-2 torr to 10-4 torr) is economically more viable and yields faster deposition of SiGeSn films. This study outlines the use of a cost-effective Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor to study the impact of substrate temperature and substrate type on the growth and properties of polycrystalline SiGeSn films. The onset of polycrystallinity in the films is attributed to the oxygen-rich PECVD chamber conditions explained using the Volmer-Weber (3D island) mechanism. The properties of the films were characterized using varied techniques to understand the impact of the substrate on film composition, thickness, crystallinity, and strain.
{"title":"Effect of Chamber Conditions and Substrate Type on PECVD of SiGeSn Films","authors":"V. Hariharan, Jignesh Vanjaria, A. Arjunan, G. Tompa, Hongbin Yu","doi":"10.4236/csta.2021.103004","DOIUrl":"https://doi.org/10.4236/csta.2021.103004","url":null,"abstract":"In the past studies have shown that the addition of Ge and Sn into Si lattice to form SiGeSn enhances its carrier mobility and band-gap properties. Conventionally SiGeSn epitaxial films are grown using Ultra-High Vacuum (UHV) conditions with pressures ranging from 10-8 torr to 10-10 torr which makes high volume manufacturing very expensive. On the contrary, the use of low-pressure CVD processes (vacuum levels of 10-2 torr to 10-4 torr) is economically more viable and yields faster deposition of SiGeSn films. This study outlines the use of a cost-effective Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor to study the impact of substrate temperature and substrate type on the growth and properties of polycrystalline SiGeSn films. The onset of polycrystallinity in the films is attributed to the oxygen-rich PECVD chamber conditions explained using the Volmer-Weber (3D island) mechanism. The properties of the films were characterized using varied techniques to understand the impact of the substrate on film composition, thickness, crystallinity, and strain.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48149860","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 : 2021-03-04DOI: 10.4236/CSTA.2021.102003
T. Moriguchi, M. Okuyama, Venkataprasad Jalli
Viologens (N,N'-dimethyl-4,4-bipyridinium) are advanced functional materials, found important applications in electrochromic devices, molecular machines, organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In this article, we investigated the design, synthesis and photophysical properties of N,N'-dimethyl-2,5-Bis(pyridinium)oxadiazole 4 and its precursor 2,5- Bis(pyridine)oxadiazole 2. The crystal structure and photophysical properties of viologen 4 and precursor 2 have been determined. The viologen molecule 4 crystallized in monoclinic form, space group P21/n with four molecules in unit cell. Precursor molecule 2 also crystalized in monoclinic form, space group C2/c with four molecules in unit cell. From X-rd data, we found three cations in the molecular structure of viologen molecule 4, which is unusual in viologens. In the three-dimensional molecular packing diagram of molecule 4, the three cations and iodate anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and C—H···I. The dihedral angle between planes having oxadiazole and two benzene rings are 5° and 8°, suggesting the molecule 4 is a slightly strained one. The molecular structure of precursor molecule 2 stabilized by C···C and N···H short contacts between the molecules. The molecule 4 displayed strong absorbance at 315 nm and emissions between 390 - 410 nm.
{"title":"Design, Synthesis, Crystal Structure and Photophysical Properties of New Oxadiazole Extended Viologen Fluorophore","authors":"T. Moriguchi, M. Okuyama, Venkataprasad Jalli","doi":"10.4236/CSTA.2021.102003","DOIUrl":"https://doi.org/10.4236/CSTA.2021.102003","url":null,"abstract":"Viologens \u0000(N,N'-dimethyl-4,4-bipyridinium) are advanced functional materials, \u0000found important applications in electrochromic devices, molecular machines, \u0000organic batteries, and carbohydrate oxidation catalysts in alkaline fuel. In \u0000this article, we investigated the design, synthesis and photophysical properties \u0000of N,N'-dimethyl-2,5-Bis(pyridinium)oxadiazole 4 and its \u0000precursor 2,5- Bis(pyridine)oxadiazole 2. The crystal structure and photophysical properties of viologen 4 and precursor 2 have been \u0000determined. The viologen molecule 4 crystallized in monoclinic form, \u0000space group P21/n with four molecules in unit cell. \u0000Precursor molecule 2 also crystalized in monoclinic form, space group C2/c with four molecules in unit cell. From \u0000X-rd data, we found three cations in the molecular structure of viologen \u0000molecule 4, which is unusual in viologens. In the three-dimensional \u0000molecular packing diagram of molecule 4, the three cations and iodate \u0000anions are stabilized by C···C, C···I, N···I, N···H, H···I, N—H···I and \u0000C—H···I. The dihedral angle between planes having oxadiazole and two benzene \u0000rings are 5° and 8°, suggesting the molecule 4 is a slightly strained \u0000one. The molecular structure of precursor molecule 2 stabilized by C···C \u0000and N···H short contacts between the molecules. The molecule 4 displayed \u0000strong absorbance at 315 nm and emissions between 390 - 410 nm.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47473165","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 : 2021-01-01DOI: 10.4236/csta.2021.104005
Albert S. Lundemba, Dikima D. Bibelayi, P. V. Tsalu, P. Wood, J. Cole, J. S. Kayembe, Zéphirin G. Yav
Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recogni-tion and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R 1 -X-R 2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R 1 or X-R 2 antibonding orbital.
{"title":"Chalcogen Bonds in Small-Organic Molecule Compounds Derived from the Cambridge Structural Database (CSD)","authors":"Albert S. Lundemba, Dikima D. Bibelayi, P. V. Tsalu, P. Wood, J. Cole, J. S. Kayembe, Zéphirin G. Yav","doi":"10.4236/csta.2021.104005","DOIUrl":"https://doi.org/10.4236/csta.2021.104005","url":null,"abstract":"Growing interest in non-covalent interactions involving chalcogen atoms has been ascribed to their importance in crystal engineering, molecular recogni-tion and macromolecular edifices. The present study is dealing with chalcogen bonds involving divalent Sulphur, Selenium and Tellurium atoms, acting as sigma-hole donors, in small-molecule compounds using the Cambridge Structural Database (CSD) in conjunction with ab initio calculations. Results derived from CSD surveys and computational study revealed that nucleophiles formed complexes with the chalcogen-bond donors R 1 -X-R 2 (X = S, Se or Te). The main forces stabilizing the complexes were chalcogen bonds, enhanced by dispersion interactions. Complexation pattern and energetics show that nucleophile bonding at divalent S, Se and Te atoms is a relatively strong and directed interaction. The bond consists of a charge transfer from a nucleophile atom lone pair to an X-R 1 or X-R 2 antibonding orbital.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70482651","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 compound, tris-(5-methylbenzimidazole) tris-(oxalato)-aluminate (III) trihydrate, (C8H9N2)3[Al(C2O4)3]∙3H2O, was synthesized by slow evaporation at room temperature and characterized by single crystal X-ray diffraction and X-ray powder diffraction, infrared (IR), ultraviolet (UV-visible) spectroscopies, and thermal analysis. The results show that this complex crystallizes in the monoclinic system, space group P21/c, with the mesh parameters a = 13.499(7) Å, b = 14.872(9) Å, c = 16.995(5) Å, ß = 91.44(3) ̊, V = 3411(3) Å and Z = 4. The formula unit is composed of tris-(oxalato)-aluminate [Al(C2O4)3] anions, tris-(5-methylbenzimidazole) cations and three uncoordinated water molecules. The geometry of the aluminum ion is octahedral, formed by six oxygen atoms belonging to three oxalate anions serving as chelating ligands. Cohesion of the structure is ensured by intermolecular hydrogen bonds of O-H...O, N-H...O type linking ionic entities and water molecules as well as by π-π and π-π* between cycles of 5-methylbenzimidazole cations. In order to clarify the intermolecular interactions formed by the organic cations and inorganic anions, an analysis of the calculated Hirshfeld surfaces was used. The UV-Vis spectrum reveals an optical band gap width of 2.88 eV, which shows that this compound has a semiconductor material behavior.
采用室温慢蒸发法制备了化合物(C8H9N2)3[Al(C2O4)3]∙3H2O，并用单晶x射线衍射、x射线粉末衍射、红外(IR)、紫外(uv -可见)光谱和热分析对化合物进行了表征。结果表明，该配合物在单斜晶系P21/c空间群中结晶，其网格参数为a = 13.499(7) Å， b = 14.872(9) Å， c = 16.995(5) Å， ß = 91.44(3)∶∶V = 3411(3)∶Å， Z = 4。该分子式单元由三(草酸)-铝酸盐[Al(C2O4)3]阴离子、三(5-甲基苯并咪唑)阳离子和三个不配位水分子组成。铝离子的几何形状为八面体，由三个草酸阴离子的六个氧原子组成，作为螯合配体。分子间氢键保证了结构的内聚性。O - h……O型连接离子实体和水分子，以及在5-甲基苯并咪唑阳离子环之间的π-π和π-π*。为了阐明有机阳离子和无机阴离子形成的分子间相互作用，对计算的赫希菲尔德表面进行了分析。紫外可见光谱显示该化合物的光学带隙宽度为2.88 eV，表明该化合物具有半导体材料的特性。
{"title":"Synthesis, Structural, Spectroscopic, Thermal, Optical Studies and Hirshfeld Surface Analysis of a New Aluminum Complex: (C<sub>8</sub>H<sub>9</sub>N<sub>2</sub>)<sub>3</sub>[Al(C<sub>2</sub>O<sub>4</sub>)<sub>3</sub>]3H<sub>2</sub>O","authors":"Amal Arouri, R. Dridi, L. Jouffret, M. Zid","doi":"10.4236/csta.2019.83003","DOIUrl":"https://doi.org/10.4236/csta.2019.83003","url":null,"abstract":"The compound, tris-(5-methylbenzimidazole) tris-(oxalato)-aluminate (III) trihydrate, (C8H9N2)3[Al(C2O4)3]∙3H2O, was synthesized by slow evaporation at room temperature and characterized by single crystal X-ray diffraction and X-ray powder diffraction, infrared (IR), ultraviolet (UV-visible) spectroscopies, and thermal analysis. The results show that this complex crystallizes in the monoclinic system, space group P21/c, with the mesh parameters a = 13.499(7) Å, b = 14.872(9) Å, c = 16.995(5) Å, ß = 91.44(3) ̊, V = 3411(3) Å and Z = 4. The formula unit is composed of tris-(oxalato)-aluminate [Al(C2O4)3] anions, tris-(5-methylbenzimidazole) cations and three uncoordinated water molecules. The geometry of the aluminum ion is octahedral, formed by six oxygen atoms belonging to three oxalate anions serving as chelating ligands. Cohesion of the structure is ensured by intermolecular hydrogen bonds of O-H...O, N-H...O type linking ionic entities and water molecules as well as by π-π and π-π* between cycles of 5-methylbenzimidazole cations. In order to clarify the intermolecular interactions formed by the organic cations and inorganic anions, an analysis of the calculated Hirshfeld surfaces was used. The UV-Vis spectrum reveals an optical band gap width of 2.88 eV, which shows that this compound has a semiconductor material behavior.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70483106","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}
Pierre R. Ndong, M. Signé, Patrice T. Kenfack, Y. Mbiangué, Gouet Bebga, E. Wenger
A new organic-inorganic hybrid salt piperidinium trans-diaquabis(oxalato)- chromate(III) tetrahydrate, (C5H10NH2)[Cr(C2O4)2(H2O)2]·4H2O (1), has been synthesized in water and characterized by FTIR and UV-Vis spectroscopies, elemental and thermal analyses and by single-crystal X-ray diffraction. 1 crystallizes in the orthorhombic non-centrosymmetric space group Cmc21 with the unit cell parameters a = 7.4329(3), b = 9.9356(5), c = 23.6756(11) A, α = β = γ = 90°, V = 1748.45(14) A3 and Z = 4. The structure of 1 consists of [Cr(C2O4)2(H2O)2]- mononuclear anions, piperidinium cations and uncoordinated water molecules. The CrIII ion in the complex [Cr(C2O4)2(H2O)2]- is coordinated in a slightly distorted octahedral environment by four O atoms from two chelating oxalate dianions in the equatorial plane, and two O atoms from trans-coordinated water molecules occupying the apical positions. In the crystal, N-H···O and O-H···O hydrogen bond interactions connect the components into a 3-D framework. The IR spectrum of 1 is consistent with the presence of the various molecular building constituents, namely oxalato and aqua ligands, piperidinium cations and solvent water molecules. The UV-Vis spectrum shows two absorption bands around 564 and 416 nm which are compatible with an anionic chromium(III) complex in an octahedral environment. Thermal analysis shows a three-step decomposition of 1, leading to formation of a metal oxide residue.
在水中合成了一种新型的有机-无机杂化盐，(C5H10NH2)[Cr(C2O4)2(H2O)2]·4H2O(1)，并用红外光谱、紫外可见光谱、元素分析、热分析和单晶x射线衍射对其进行了表征。1在正交非中心对称空间群Cmc21中结晶，晶胞参数a = 7.4329(3)， b = 9.9356(5)， c = 23.6756(11) a， α = β = γ = 90°，V = 1748.45(14) A3, Z = 4。1的结构由[Cr(C2O4)2(H2O)2]-单核阴离子、胡椒离子和不配位水分子组成。配合物[Cr(C2O4)2(H2O)2]-中的CrIII离子在稍微扭曲的八面体环境中由两个螯合草酸根离子的四个O原子在赤道平面上配位，两个来自反配位的水分子的两个O原子占据顶端位置。在晶体中，N-H··O和O- h··O氢键相互作用将这些成分连接成一个三维框架。1的红外光谱与各种分子构建成分的存在一致，即草酸和水配体、哌替啶阳离子和溶剂水分子。紫外可见光谱在564和416 nm处显示出与阴离子铬(III)配合物在八面体环境下相容的两个吸收带。热分析表明，1分三步分解，导致形成金属氧化物残留物。
{"title":"Synthesis, Characterization and Thermal Analysis of an Organic-Inorganic Hybrid Salt Involving Trans-Diaquabis(oxalato-κ2O1,O2)chromate(III) Complex Anion with Piperidinium as Counter Cation","authors":"Pierre R. Ndong, M. Signé, Patrice T. Kenfack, Y. Mbiangué, Gouet Bebga, E. Wenger","doi":"10.4236/csta.2020.92004","DOIUrl":"https://doi.org/10.4236/csta.2020.92004","url":null,"abstract":"A new organic-inorganic hybrid salt piperidinium trans-diaquabis(oxalato)- chromate(III) \u0000tetrahydrate, (C5H10NH2)[Cr(C2O4)2(H2O)2]·4H2O \u0000(1), has been synthesized in water and characterized by FTIR and UV-Vis \u0000spectroscopies, elemental and thermal analyses and by single-crystal X-ray \u0000diffraction. 1 crystallizes in the \u0000orthorhombic non-centrosymmetric space group Cmc21 with the unit cell parameters a = \u00007.4329(3), b = 9.9356(5), c = 23.6756(11) A, α = β = γ = 90°, V = 1748.45(14) A3 and Z = 4. The structure of 1 consists of [Cr(C2O4)2(H2O)2]- mononuclear anions, piperidinium cations and uncoordinated water molecules. The \u0000CrIII ion in the complex [Cr(C2O4)2(H2O)2]- is coordinated in a slightly distorted octahedral environment by four O atoms \u0000from two chelating oxalate dianions in the equatorial plane, and two O atoms \u0000from trans-coordinated water \u0000molecules occupying the apical positions. In the crystal, N-H···O and O-H···O hydrogen bond \u0000interactions connect the components into a 3-D framework. The IR spectrum of 1 is consistent with the presence of the various molecular building \u0000constituents, namely oxalato and aqua ligands, piperidinium cations and solvent \u0000water molecules. The UV-Vis spectrum shows two absorption bands around 564 and \u0000416 nm which are compatible with an anionic chromium(III) complex in an \u0000octahedral environment. Thermal analysis shows a three-step decomposition of 1, \u0000leading to formation of a metal oxide residue.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46713123","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}
Glodi M. Ndefi, Albert S. Lundemba, Dikima D. Bibelayi, J. T. Kilembe, Eliakim M. Kambale, Celine W. Kadima, Zéphyrin G. Yav
Inactivation of Glucokinase (GK) is associated with diabetes. Therefore, design of drugs targeting the GK activator site is currently integrated in the strategy of the diabetes treatment. The present work investigated the affinity of 30 ligands to GK based on molecular docking using the Gold 5.6 program. Glucokinase’s structure was derived from the Protein Data Bank (PDB Code 3S41), while the ligands were seleno, sulfo and oxo derivatives of the co-crystallized carboxamide activator (PDB code: S41). The results of the ligand-protein docking revealed that GK formed thermodynamically stable complexes with all ligands. The main forces stabilizing the complexes are lipophilic interactions, enhanced by hydrogen bonds. Ligand molecular areas responsible for lipophilic and hydrogen bonding contacts with amino acid residues in the allosteric site of GK were evidenced by molecular electrostatic potentials (MEPs). Interestingly, twelve of the S41 derivatives interacted with GK more strongly than the co-crystallized activator, while maintaining the lipophilic contacts with key amino acid residues like Arg63, which are catalytically crucial for therapeutic properties of GK activators (GKAs). It is noteworthy that divalent Se and S atoms were also involved in chalcogen bonds in the GKA site. Those bonds were nearly linear like hydrogen bonds. Such bond directionality should guide the design of pharmacophoric ligands containing chalcogen atoms.
{"title":"Docking of Glycokinase with Oxo, Sulfo, and Seleno Derivatives of the Carboxamide Activator S41","authors":"Glodi M. Ndefi, Albert S. Lundemba, Dikima D. Bibelayi, J. T. Kilembe, Eliakim M. Kambale, Celine W. Kadima, Zéphyrin G. Yav","doi":"10.4236/csta.2020.92003","DOIUrl":"https://doi.org/10.4236/csta.2020.92003","url":null,"abstract":"Inactivation of Glucokinase (GK) is associated with diabetes. Therefore, design of drugs targeting the GK activator site is currently integrated in the strategy of the diabetes treatment. The present work investigated the affinity of 30 ligands to GK based on molecular docking using the Gold 5.6 program. Glucokinase’s structure was derived from the Protein Data Bank (PDB Code 3S41), while the ligands were seleno, sulfo and oxo derivatives of the co-crystallized carboxamide activator (PDB code: S41). The results of the ligand-protein docking revealed that GK formed thermodynamically stable complexes with all ligands. The main forces stabilizing the complexes are lipophilic interactions, enhanced by hydrogen bonds. Ligand molecular areas responsible for lipophilic and hydrogen bonding contacts with amino acid residues in the allosteric site of GK were evidenced by molecular electrostatic potentials (MEPs). Interestingly, twelve of the S41 derivatives interacted with GK more strongly than the co-crystallized activator, while maintaining the lipophilic contacts with key amino acid residues like Arg63, which are catalytically crucial for therapeutic properties of GK activators (GKAs). It is noteworthy that divalent Se and S atoms were also involved in chalcogen bonds in the GKA site. Those bonds were nearly linear like hydrogen bonds. Such bond directionality should guide the design of pharmacophoric ligands containing chalcogen atoms.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43261328","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}
In this work, C-Scan Acoustic Scanning Microscopy (ASM) is used to map the defects of three SiC samples. The acoustic images indicate that numerous defects with different shapes and area sexist in the wafers. Some of the defects have areas of more than 100,000 μm2. The number of defects ranges from 1 to 50 defects/wafer. Defect mapping is essential for defect repairing or avoidance. This work shows that ASM can locate the precise positions of the crystallographic defects, which enables defects repair and yield enhancement.
{"title":"Investigation of Inhomogeneity in Single Crystal SiC Wafers Using C-Scan Acoustic Scanning Microscopy","authors":"I. Abdel-Motaleb","doi":"10.4236/csta.2020.91001","DOIUrl":"https://doi.org/10.4236/csta.2020.91001","url":null,"abstract":"In this work, C-Scan Acoustic Scanning Microscopy (ASM) is used to map the defects of three SiC samples. The acoustic images indicate that numerous defects with different shapes and area sexist in the wafers. Some of the defects have areas of more than 100,000 μm2. The number of defects ranges from 1 to 50 defects/wafer. Defect mapping is essential for defect repairing or avoidance. This work shows that ASM can locate the precise positions of the crystallographic defects, which enables defects repair and yield enhancement.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44826424","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}
E. Mainsah, Sally-Judith E. Ntum, M. Conde, G. T. Chi, J. Raftery, P. Ndifon
A new hydrogen bonded Cobalt(II) Schiff base complex, N’-(pyridine-4-carboxaldehyde) isonicotinoylhydrazone Cobalt(II), has been synthesized from isoniazid and pyridine-4-carboxaldehyde and characterized by IR spectroscopy, 1H-NMR, elemental analysis, TGA and single crystal X-ray structure determination. X-ray crystal structure analysis shows an octahedral complex with a metal centre coordinated to two ligand molecules through the pyridine nitrogen atoms and four water molecules and containing two nitrate groups as counter ions. The complex crystallizes in the monoclinic crystal system and P2(1)/n space group. The unit cell dimensions are: a = 7.2108(4) A, b = 16.6020(9) A, c = 13.0389(6) A,α = 90°, β = 103.972(4)°, γ = 90°. The molecule is symmetrical about the cobalt centre as observed from the 1H-NMR and 13C-NMR and confirmed by the single crystal X-ray structure of the complex. Thermogravimetric analysis shows two steps decomposition of the complex to leave a metal oxide residue. The title compound is expected to be biologically active as one of the precursors (isoniazid) is a therapeutic agent with well-established clinical applications.
以异烟肼和吡啶-4-甲醛为原料合成了一种新的氢键钴(II)希夫碱配合物N′-(吡啶-4-甲醛)异烟碱腙钴(II)，并用红外光谱、1H-NMR、元素分析、热重分析和单晶x射线结构测定对其进行了表征。x射线晶体结构分析表明，该八面体配合物的金属中心通过吡啶氮原子和四个水分子与两个配体分子配位，并含有两个硝酸基作为反离子。该配合物在单斜晶系和P2(1)/n空间群中结晶。单晶胞尺寸为:a = 7.2108(4) a, b = 16.6020(9) a, c = 13.0389(6) a，α = 90°，β = 103.972(4)°，γ = 90°。通过1H-NMR和13C-NMR观察到分子的钴中心是对称的，并通过配合物的单晶x射线结构证实了这一点。热重分析表明，络合物的分解分为两个步骤，留下金属氧化物残留物。标题化合物有望具有生物活性，因为前体之一(异烟肼)是一种具有良好临床应用的治疗剂。
{"title":"Synthesis, Characterization and Crystal Structure of Cobalt(II) Complex of a Schiff Base Derived from Isoniazid and Pyridine-4-Carboxaldehyde","authors":"E. Mainsah, Sally-Judith E. Ntum, M. Conde, G. T. Chi, J. Raftery, P. Ndifon","doi":"10.4236/csta.2019.84004","DOIUrl":"https://doi.org/10.4236/csta.2019.84004","url":null,"abstract":"A new hydrogen bonded Cobalt(II) Schiff base complex, N’-(pyridine-4-carboxaldehyde) isonicotinoylhydrazone Cobalt(II), has been synthesized from isoniazid and pyridine-4-carboxaldehyde and characterized by IR spectroscopy, 1H-NMR, elemental analysis, TGA and single crystal X-ray structure determination. X-ray crystal structure analysis shows an octahedral complex with a metal centre coordinated to two ligand molecules through the pyridine nitrogen atoms and four water molecules and containing two nitrate groups as counter ions. The complex crystallizes in the monoclinic crystal system and P2(1)/n space group. The unit cell dimensions are: a = 7.2108(4) A, b = 16.6020(9) A, c = 13.0389(6) A,α = 90°, β = 103.972(4)°, γ = 90°. The molecule is symmetrical about the cobalt centre as observed from the 1H-NMR and 13C-NMR and confirmed by the single crystal X-ray structure of the complex. Thermogravimetric analysis shows two steps decomposition of the complex to leave a metal oxide residue. The title compound is expected to be biologically active as one of the precursors (isoniazid) is a therapeutic agent with well-established clinical applications.","PeriodicalId":67661,"journal":{"name":"晶体结构理论与应用(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41945957","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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