Acta Crystallographica Section B-structural Science最新文献_第3页

On the structural relations of malachite. II. The brochantite MDO polytypes. 孔雀石的结构关系。2枝状石MDO多型。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-12-01 Epub Date: 2012-10-23 DOI: 10.1107/S0108768112039274

Frank Girgsdies, Malte Behrens

引用次数: 0

Structures of four polymorphs of the pesticide dithianon solved from X-ray powder diffraction data. 用x射线粉末衍射数据解析农药二硫农四种多晶型结构。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-12-01 Epub Date: 2012-10-23 DOI: 10.1107/S0108768112036191

Ivan Halasz, Robert Dinnebier, Tiziana Chiodo, Heidi Saxell

引用次数: 5

Experimental and database-transferred electron-density analysis and evaluation of electrostatic forces in coumarin-102 dye. 香豆素-102染料中静电力的实验与数据库转移电子密度分析与评价。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-12-01 Epub Date: 2012-11-16 DOI: 10.1107/S0108768112042826

Yvon Bibila Mayaya Bisseyou, Nouhza Bouhmaida, Benoit Guillot, Claude Lecomte, Noel Lugan, Noureddine Ghermani, Christian Jelsch

{"title":"Experimental and database-transferred electron-density analysis and evaluation of electrostatic forces in coumarin-102 dye.","authors":"Yvon Bibila Mayaya Bisseyou, Nouhza Bouhmaida, Benoit Guillot, Claude Lecomte, Noel Lugan, Noureddine Ghermani, Christian Jelsch","doi":"10.1107/S0108768112042826","DOIUrl":"https://doi.org/10.1107/S0108768112042826","url":null,"abstract":"The electron-density distribution of a new crystal form of coumarin-102, a laser dye, has been investigated using the Hansen-Coppens multipolar atom model. The charge density was refined versus high-resolution X-ray diffraction data collected at 100 K and was also constructed by transferring the charge density from the Experimental Library of Multipolar Atom Model (ELMAM2). The topology of the refined charge density has been analysed within the Bader `Atoms In Molecules' theory framework. Deformation electron-density peak heights and topological features indicate that the chromen-2-one ring system has a delocalized π-electron cloud in resonance with the N (amino) atom. The molecular electrostatic potential was estimated from both experimental and transferred multipolar models; it reveals an asymmetric character of the charge distribution across the molecule. This polarization effect is due to a substantial charge delocalization within the molecule. The molecular dipole moments derived from the experimental and transferred multipolar models are also compared with the liquid and gas-phase dipole moments. The substantial molecular dipole moment enhancements observed in the crystal environment originate from the crystal field and from intermolecular charge transfer induced and controlled by C-H···O and C-H···N intermolecular hydrogen bonds. The atomic forces were integrated over the atomic basins and compared for the two electron-density models.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 6","pages":"646-60"},"PeriodicalIF":1.9,"publicationDate":"2012-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112042826","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31058424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Four polymorphs (polytypes) of 5,6-dimethylbenzofurazan 1-oxide. 5,6-二甲基苯并呋喃唑1-氧化物的4个多态性(多型)。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-09-13 DOI: 10.1107/S0108768112037457

Doyle Britton, Victor G Young, Wayland E Noland, Matthew J Pinnow, Christopher M Clark

引用次数: 3

Comparative modular analysis of two complex sulfosalt structures: sterryite, Cu(Ag,Cu)3Pb19(Sb,As)22(As-As)S56, and parasterryite, Ag4Pb20(Sb,As)24S58. 两种复杂亚硫酸盐结构的比较模块化分析:铜辉石Cu(Ag,Cu)3Pb19(Sb,As)22(As-As)S56和副辉石Ag4Pb20(Sb,As)24S58。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-09-13 DOI: 10.1107/S0108768112034027

Yves Moëlo, Catherine Guillot-Deudon, Michel Evain, Paolo Orlandi, Cristian Biagioni

{"title":"Comparative modular analysis of two complex sulfosalt structures: sterryite, Cu(Ag,Cu)3Pb19(Sb,As)22(As-As)S56, and parasterryite, Ag4Pb20(Sb,As)24S58.","authors":"Yves Moëlo, Catherine Guillot-Deudon, Michel Evain, Paolo Orlandi, Cristian Biagioni","doi":"10.1107/S0108768112034027","DOIUrl":"https://doi.org/10.1107/S0108768112034027","url":null,"abstract":"The crystal structures of two very close, but distinct complex minerals of the lead sulfosalt group have been solved: sterryite, Cu(Ag,Cu)(3)Pb(19)(Sb,As)(22)(As-As)S(56), and parasterryite, Ag(4)Pb(20)(Sb,As)(24)S(58). They are analyzed and compared according to modular analysis. The fundamental building block is a complex column centred on a Pb(6)S(12) triangular prismatic core, with two additional long and short arms. The main chemical and topological differences relate to the short arm, which induces a relative a/4 shift (~2 Å along the elongation parameter) of the constitutive rod layers, as illustrated by distinct cell settings within the same space group (P2(1)/n and P2(1)/c, respectively). Selection of the shortest (i.e. strongest) (Sb,As)-S bonds permitted to enhance the polymeric organization of (Sb,As) atoms with triangular pyramidal coordination. These two quasi-homeotypic structures are expanded derivatives of owyheeite, Ag(3)Pb(10)Sb(11)S(28). The hierarchy of organization levels from zero- to three-dimensional entities is subordinated to building operators, which appear as the driving force for the construction of such complex structures. Minor cations (Ag, Cu) or the As-As pair in sterryite secure the final locking, which favours the formation of one or the other compound.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 5","pages":"480-92"},"PeriodicalIF":1.9,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112034027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30916923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 16

Single-crystal investigation of L-tryptophan with Z' = 16. Z′= 16时l -色氨酸单晶研究。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-09-13 DOI: 10.1107/S0108768112033484

Carl Henrik Görbitz, Karl Wilhelm Törnroos, Graeme M Day

引用次数: 49

Theoretical hardness calculated from crystallo-chemical data for MoS2 and WS2 crystals and nanostructures. 从MoS2和WS2晶体和纳米结构的晶体化学数据计算理论硬度。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-08-17 DOI: 10.1107/S0108768112033149

M I Petrescu

{"title":"Theoretical hardness calculated from crystallo-chemical data for MoS2 and WS2 crystals and nanostructures.","authors":"M I Petrescu","doi":"10.1107/S0108768112033149","DOIUrl":"https://doi.org/10.1107/S0108768112033149","url":null,"abstract":"The calculation of the hardness of Mo and W disulfides using a crystallo-chemical model provides a unique opportunity to obtain separate quantitative information on the maximum hardness H(max) governed by strong intra-layer covalent bonds acting within the (0001) plane versus the minimum hardness H(min) governed by weak inter-layer van der Waals bonds acting along the c-axis of the hexagonal lattice. The penetration hardness derived from fundamental crystallo-chemical data (confirmed by experimental determinations) proved to be far lower in MS(2) (M = Mo, W) than in graphite and hexagonal BN, both for H(max) (H(graph)/H(MoS2) = 3.85; H(graph)/H(WS2) = 3.60; H(hBN)/H(MoS2) = 2.54; H(hBN)/H(WS2) = 2.37) as well as for H(min) (H(graph)/H(MoS2) = 6.22; H(graph)/H(WS2) = 5.87; H(hBN)/H(MoS2) = 4.72; H(hBN)/H(WS2) = 4.46). However, the gap between H(max) and H(min) is considerably larger in MS(2) (M = Mo,W), as indicated by H(max)/H(min) being 279 in 2H-MoS(2), 282 in 2H-WS(2), 173 in graphite and 150 in hBN. The gap was found to be even larger in MS(2) (M = Mo, W) nanostructures. These findings help to explain the excellent properties of MS(2) (M = Mo, W) as solid lubricants in high tech fields, either as bulk 2H crystals (inter-layer shear and peeling off lubricating mechanisms), or especially as onion-like fullerene nanoparticles (rolling/sliding mechanisms).","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 5","pages":"501-10"},"PeriodicalIF":1.9,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112033149","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30916925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Structure of twisted BNC nanotubes with polygonal cross-section. 具有多边形截面的扭曲BNC纳米管的结构。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-09-13 DOI: 10.1107/S0108768112034635

Vladimir Blank, Leonid Ivanov, Boris Kulnitskiy, Igor Perezhogin, Evgene Polyakov, Alexander Semenov

引用次数: 0

Topological studies of three related metal-organic frameworks of GdIII and 5-nitroisophthalate. GdIII和5-硝基间苯二甲酸三种相关金属有机骨架的拓扑结构研究。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-08-17 DOI: 10.1107/S0108768112032053

Kate Davies, Susan A Bourne, Lars Ohrström, Clive L Oliver

引用次数: 5

Crystal structures of calcium hemicarboaluminate and carbonated calcium hemicarboaluminate from synchrotron powder diffraction data. 从同步加速器粉末衍射数据分析半碳铝酸钙和碳化半碳铝酸钙的晶体结构。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2012-10-01 Epub Date: 2012-08-17 DOI: 10.1107/S010876811203042X

Tomče Runčevski, Robert E Dinnebier, Oxana V Magdysyuk, Herbert Pöllmann

{"title":"Crystal structures of calcium hemicarboaluminate and carbonated calcium hemicarboaluminate from synchrotron powder diffraction data.","authors":"Tomče Runčevski, Robert E Dinnebier, Oxana V Magdysyuk, Herbert Pöllmann","doi":"10.1107/S010876811203042X","DOIUrl":"https://doi.org/10.1107/S010876811203042X","url":null,"abstract":"One of the main phases formed at the beginning of the carbonation reaction of cementitious building materials is the calcium hemicarboaluminate (abbreviated as Hc). This AFm (shorthand for hydrated calcium aluminate phases structurally related to hydrocalumite) phase was synthesized, crystallized and then studied by synchrotron X-ray powder diffraction and micro-Raman spectroscopy. At room temperature and standard experimental conditions two major cementitious phases were detected, the Hc phase (as a major phase) and carbonated calcium hemicarboaluminate (abbreviated as cHc). By increasing the temperature the Hc form transforms into cHc. The crystal structures of these important AFm phases were successfully solved and refined in the R3c space group of the trigonal crystal system. Hc has the unit-cell parameters a = 5.7757 (1) and c = 48.812 (2) Å, and cHc the unit-cell parameters a = 5.7534 (1) and c = 46.389 (1) Å. The two crystal structures are composed of positively charged main layers, [Ca(4)Al(2)(OH)(12)](2+), and negatively charged interlayers, [OH(2n)(CO(3))(1 - n)·4H(2)O](2-). The structure of the main layers is typical of the AFm family. Conversely, the interlayer region has a characteristic structure built up from water molecules and statistically distributed anions. In the interlayer, the Hc carbonate and hydroxyl anions are distributed in a 0.25:0.5 ratio, whereas the ratio of the anions in the cHc interlayers is 0.4:0.2.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"68 Pt 5","pages":"493-500"},"PeriodicalIF":1.9,"publicationDate":"2012-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S010876811203042X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30916924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 98