Acta Crystallographica Section B-structural Science最新文献

The role of the coordination defect (CD) in the structures of anion-deficient, fluorite-related compounds. 配位缺陷(CD)在缺乏阴离子的萤石相关化合物结构中的作用。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768112051105

D J M Bevan, Lisandra L Martin, Raymond L Martin

引用次数: 2

Weak intermolecular hydrogen and halogen interactions in an isomorphous halogen series of pseudoterpyridine Zn(II) complexes. 伪三联吡啶锌(II)同形卤素系列配合物中氢与卤素的弱分子间相互作用。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768112050434

Florina Dumitru, Yves-Marie Legrand, Mihail Barboiu, Arie van der Lee

{"title":"Weak intermolecular hydrogen and halogen interactions in an isomorphous halogen series of pseudoterpyridine Zn(II) complexes.","authors":"Florina Dumitru, Yves-Marie Legrand, Mihail Barboiu, Arie van der Lee","doi":"10.1107/S0108768112050434","DOIUrl":"https://doi.org/10.1107/S0108768112050434","url":null,"abstract":"The synthesis and characterization of a series of halogen-substituted pseudoterpyridine Zn(II) homoleptic mononuclear complexes, based on ligands L(11)-L(44) [2,6-pyridinedicarboxaldehydebis(p-R-phenylimines), R = F, Cl, Br, I] are reported. Neither of the structures contain relatively strong classical hydrogen bonds (OH···O, NH···O, OH···N, NH···N) and the structure packing is thus determined by a subtle interplay of weaker interactions. Isostructurality of the four halogen analogues is very rare, and in this study -Br, -Cl and -F are found to be isostructural in different degrees, whereas -I is not. Interestingly, although it is closely isostructural to the -Cl and -Br compounds, the F analogue is shown not to form F···O bonds, while the Cl and the Br analogues do form Hal···O bonds. This raises an important question on the role of Hal···O bonds in the structuration of the crystal packing, particularly the stabilization effect. Similarly, while the CH···Hal interaction seems to give one-dimensional cohesion in the -Cl and -Br analogues, this feature is absent in the -F analogue, despite its close isostructurality. CH···O interactions appear to dominate to a first degree the cohesion between the anionic trifluoromethanesulfonate network and the cationic Zn-pyridinedicarboxaldehydebis(p-R-phenylimines) network. The analysis of these interactions is corroborated by reduced density gradient calculations based on promolecular densities.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"69 Pt 1","pages":"43-54"},"PeriodicalIF":1.9,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112050434","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290484","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: 3

Structural transformations in the low-temperature grown GaAs with superlattices of Sb and P δ-layers. 具有Sb和P δ层超晶格的低温生长GaAs的结构转变。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768113000189

M V Baidakova, N A Bert, V V Chaldyshev, V N Nevedomsky, M A Yagovkina, V V Preobrazhenskii, M A Putyato, B R Semyagin

引用次数: 6

Electronic influence of β-diketonato-type ligands on the coordination of 1,5-cyclooctadiene to palladium(II) as defined by 'Venus fly trap' geometric parameters. 用“维纳斯捕蝇器”几何参数定义的β-二酮酮型配体对1,5-环二烯与钯(II)配位的电子影响

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2012-12-20 DOI: 10.1107/S0108768112046733

Tania N Hill, Andreas Roodt, Gideon Steyl

引用次数: 6

A high-pressure polymorph of chlorpropamide formed on hydrostatic compression of the α-form in saturated ethanol solution. 氯丙酰胺α-型在饱和乙醇溶液中经静水压压缩形成高压多晶型。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768112051142

Yury V Seryotkin, Tatiana N Drebushchak, Elena V Boldyreva

{"title":"A high-pressure polymorph of chlorpropamide formed on hydrostatic compression of the α-form in saturated ethanol solution.","authors":"Yury V Seryotkin, Tatiana N Drebushchak, Elena V Boldyreva","doi":"10.1107/S0108768112051142","DOIUrl":"https://doi.org/10.1107/S0108768112051142","url":null,"abstract":"The crystal structure of the high-pressure polymorph (α') of an antidiabetic drug, chlorpropamide [4-chloro-N-(propylaminocarbonyl)benzenesulfonamide, C(10)H(13)ClN(2)O(3)S], which is formed at ~2.8 GPa from the α-polymorph (P2(1)2(1)2(1)) on hydrostatic compression in saturated ethanol solution, has been determined. As a result of the phase transition, the a, c and α parameters change jumpwise, whereas the changes in b parameter are continuous through the phase transition point. The high-pressure form is monoclinic (P2(1)11) and has Z' equal to 2, the two independent molecules differing in their conformations. The hydrogen bonds expand slightly in the high-pressure polymorph after the transition, and this expansion is interrelated with the changes in molecular conformations enabling a denser packing. The transition is reversible, but the crystal quality deteriorates as a result of multiple compression-decompression cycles, and a pseudomerohedral twinning accompanies the transformation.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"69 Pt 1","pages":"77-85"},"PeriodicalIF":1.9,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112051142","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290488","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: 45

Thermodynamic and structural relationships between the two polymorphs of 1,3-dimethylurea. 1,3-二甲基脲两种多晶型之间的热力学和结构关系。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2012-12-20 DOI: 10.1107/S0108768112049324

Christian Näther, Cindy Döring, Inke Jess, Peter G Jones, Christina Taouss

{"title":"Thermodynamic and structural relationships between the two polymorphs of 1,3-dimethylurea.","authors":"Christian Näther, Cindy Döring, Inke Jess, Peter G Jones, Christina Taouss","doi":"10.1107/S0108768112049324","DOIUrl":"https://doi.org/10.1107/S0108768112049324","url":null,"abstract":"The title compound exists as polymorph (I), Fdd2 with Z = 8 [Pérez-Folch et al. (1997). J. Chem. Cryst. 27, 367-369; Marsh (2004). Acta Cryst. B60, 252-253], and as polymorph (II), P2(1)2(1)2 with Z = 2 [Martins et al. (2009). J. Phys. Chem. A, 113, 5998-6003]. We have redetermined both structures at somewhat lower temperatures [(I) at 180 K rather than room temperature; (II) at 100 K rather than 150 K]. For polymorph (I) the space group Fdd2 is confirmed rather than the original choice of Cc. The molecular structures of both polymorphs are essentially identical, with exact crystallographic twofold symmetry, approximate C(2v) symmetry, and a trans orientation of the H-N-C=O moiety. In both polymorphs the molecules associate into chains of rings with graph set C(4)[R(2)(1)(6)] via bifurcated hydrogen-bond systems C(N-H)(2)···O=C. In the polar structure (I) the chains are necessarily all parallel, whereas in (II) equal numbers of parallel and antiparallel chains are present. Further physical investigations [differential scanning calorimetry (DSC), powder investigations, solvent-induced phase conversions] were undertaken: these showed: (i) that the commercially available compound consists predominantly of polymorph (II), which on heating transforms into polymorph (I) by an endothermic reaction, so that both polymorphs are related by enantiotropism; (ii) that polymorph (I) represents the more stable modification at room temperature, where polymorph (II) is metastable, with the thermodynamic transition temperature lying somewhere between 253 K and room temperature. An apparent third polymorph, consisting of fibrous needles, was shown by powder diffraction to consist of a mixture of polymorphs (I) and (II).","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"69 Pt 1","pages":"70-6"},"PeriodicalIF":1.9,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112049324","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290487","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: 15

On the shortest B(III)-O bonds. 在最短的B(III)-O键上。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768112051506

Vasyl Sidey

引用次数: 4

Structural and electronic aspects of hydrogen bonding in two polymorphs of butylene-N,N'-bis(O,O'-diarylphosphoramidate). 两种丁烯-N,N'-二(O,O'-二酰基磷酰胺)多晶体氢键的结构和电子特性。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2012-12-20 DOI: 10.1107/S0108768112048331

Khodayar Gholivand, Ali A Ebrahimi Valmoozi, Hamid R Mahzouni

{"title":"Structural and electronic aspects of hydrogen bonding in two polymorphs of butylene-N,N'-bis(O,O'-diarylphosphoramidate).","authors":"Khodayar Gholivand, Ali A Ebrahimi Valmoozi, Hamid R Mahzouni","doi":"10.1107/S0108768112048331","DOIUrl":"https://doi.org/10.1107/S0108768112048331","url":null,"abstract":"The bisphosphoramidate (C(6)H(5)O)(2)P(O)NH(CH(2))(4)NHP(O)(OC(6)H(5))(2) crystallizes in two polymorphs, one (ndl) with a needle habit from tetrahydrofuran (THF)/ethanol and another (prm) which forms prisms from H(2)O/ethanol. The molecules in the two forms differ from each other in some torsion angles and the orientation of the diaminobutane bridge, although the differences between the similar bond lengths are not significant for the two polymorphs. The geometry optimizations at the B3LYP/6-31+G* level for isolated molecules show that the two conformers which exist in the crystalline state also represent local gas-phase energy minima. The decrease in the N-H distance from the optimized to the crystal structures has been described in terms of the decrease in electron density (ρ) at the bond-critical point (b.c.p.) of the N-H bond path when the molecule participates in hydrogen bonding, comparing the results of atoms-in-molecules (AIM) and natural bond orbital (NBO) analyses for fully optimized structures ndl and prm with their hydrogen-bonded model clusters.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"69 Pt 1","pages":"55-61"},"PeriodicalIF":1.9,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112048331","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290485","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: 14

Entry point into new trimeric and tetrameric imide-based macrocyclic esters derived from isophthaloyl dichloride and methyl 6-aminonicotinate. 从二氯异苯甲酰和6-氨基烟酸甲酯衍生的新型三聚体和四聚体亚胺基大环酯的切入点。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2012-12-20 DOI: 10.1107/S0108768112047416

Pavle Mocilac, John F Gallagher

{"title":"Entry point into new trimeric and tetrameric imide-based macrocyclic esters derived from isophthaloyl dichloride and methyl 6-aminonicotinate.","authors":"Pavle Mocilac, John F Gallagher","doi":"10.1107/S0108768112047416","DOIUrl":"https://doi.org/10.1107/S0108768112047416","url":null,"abstract":"The one-step reaction of isophthaloyl dichloride with the 2-aminopyridine derivative (methyl 6-aminonicotinate) yields (i) a trimer-based macrocycle (EsIO)(3) and (ii) a tetramer-based macrocycle (EsIO)(4) in modest isolated synthetic yields (total of 25%), together with (iii) longer open-chain oligomers. The macrocyclization relies on the semi-flexible imide hinge formed by reaction of the 2-amino(pyridine) functional group with two acyl chloride functional groups. The determining factors in macrocycle synthesis are: (a) imide formation using the heteroaromatic ortho-N functionality; (b) the inherent ability of the imide to twist by 85-115° from planarity (as measured by the CO···CO imide torsion angles), thereby providing a hinge for macrocyclic ring closure or potentially (non)helical assembly in oligomer/polymer formation; (c) the conformational flexibility of the isophthaloyl group with meta-related carbonyl groups to twist and adopt either syn or anti conformations, although the syn conformation is observed structurally for all isophthaloyl groups in both (EsIO)(3) (trezimide) and (EsIO)(4) (tennimide) macrocycles.","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":"69 Pt 1","pages":"62-9"},"PeriodicalIF":1.9,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112047416","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31290486","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

The charge-flipping algorithm in crystallography. 晶体学中的电荷翻转算法。

IF 1.9 3区化学

Acta Crystallographica Section B-structural Science Pub Date : 2013-02-01 Epub Date: 2013-01-19 DOI: 10.1107/S0108768112051361

Lukáš Palatinus

引用次数: 108