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1.
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option. 相似文献
2.
Uwe‐Christoph Knig Michael Berkei Claudia Hirsch Hans Preut Terence Nigel Mitchell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):e550-e551
The preparation and X‐ray analysis of the title compound, [Sn2Br4(CH3)4(C5H9NO)], are described. The compound contains two Sn atoms in the asymmetric unit, that complexed by N‐methylpyrrolidin‐2‐one being hexacoordinated (a), the other exhibiting pentacoordination (b). The most important features are three different Sn—Br bond lengths at both Sn atoms with the following values: (a) 2.5060 (9), 2.7152 (10) and 3.7118 (10) Å; (b) 2.5084 (10), 2.5279 (9) and 3.5841 (10) Å. 相似文献
3.
The tin atom is a distorted trigonal bipyramid geometry defined by sulfur donors derived from the asymmetrically binding dithiocarbamate ligand and three ipso‐carbon atoms from the p‐fluorobenzyl substituents. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
4.
《应用有机金属化学》2017,31(10)
A tetrel bond – an interaction between a Group 14 element acting as Lewis acid centre and an electron‐donating moiety – is analysed for ZF4 (Z = Sn, Pb) complexes with NH3 and HCN species. MP2/aug‐cc‐pVTZ calculations were performed and supported by results of the quantum theory of atoms in molecules. The results of calculations show that the tetrel centre may be considered as a pentavalent one if ZF4 interacts with one NH3 or HCN ligand or even as a hexavalent centre if it interacts with two ligands; thus the hypervalency phenomenon is discussed for the complexes analysed here. The theoretical analysis is supported by a discussion of the crystal structures containing the SnF4 fragment; these structures are characterized by a hexa‐coordinated tin centre. 相似文献
5.
Seik Weng Ng 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):e86-e87
The Sn atom in catena‐poly[triphenyltin(IV)‐μ‐(3‐ureidopropionato‐O1:O3)], [Sn(C6H5)3(C4H7N2O3)]n, is five‐coordinate and has a trans‐C3SnO2 trigonal‐bipyrmidal geometry arising from bridging through the O atom of the ureido fragment of an adjacent carboxylate group. Infinite chains propagate helically along the c axis and adjacent chains are linked by N—H?O [N?O 2.851 (4) Å] hydrogen bonds into layers. 相似文献
6.
Doyle Britton 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(3):m93-m94
The structures of dimethyldithiocyanatotin(IV), [Sn(CH3)2(NCS)2], and diethyldithiocyanatotin(IV), [Sn(C2H5)2(NCS)2], have been determined. The dimethyl derivative has 2mm crystallographic symmetry and the diethyl derivative has twofold crystallographic symmetry. The experimental differences in the distances and angles around the Sn atom between the two structures agree reasonably well with the differences expected from the reaction path mapped previously [Britton & Dunitz (1981). J. Am. Chem. Soc. 103 , 2971–2979]. 相似文献
7.
Zhihai Hao Hou Chen Delong Liu Lijun Fan 《Journal of polymer science. Part A, Polymer chemistry》2012,50(24):4995-4999
Sn(0)‐mediated single electron transfer‐living radical polymerization (SET‐LRP) of acrylonitrile (AN) with carbon tetrachloride (CCl4) as initiator and hexamethylenetetramine (HMTA) as ligand in N, N‐dimethylformamide (DMF) was studied. The polymerization obeyed first order kinetic. The molecular weight of polyacrylonitrile (PAN) increased linearly with monomer conversion and PAN exhibited narrow molecular weight distributions. Increasing the content of Sn(0) resulted in an increase in the molecular weight and the molecular weight distribution. Effects of ligand and initiator were also investigated. The block copolymer PAN‐b‐polymethyl methacrylate with molecular weight at 126,130 and polydispersity at 1.36 was successfully obtained. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
8.
Uwe‐Christoph Knig Michael Berkei Claudia Hirsch Hans Preut Terence Nigel Mitchell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e450-e451
The synthesis and the X‐ray structural analysis of the title compound, μ‐chloro‐1:2κ2Cl‐trichloro‐1κCl,2κ2Cl‐tetramethyl‐1κ2C,2κ2C‐(N‐methylpyrrolidin‐2‐one)‐1κO‐ditin(IV), [Sn2Cl4(CH3)4(C5H9NO)], are described. The title compound is found to exhibit a distorted trigonal–bipyramidal geometry at both SnIV atoms. The Sn—Cl—Sn angle involving the bridging chlorine ligand is 135.56 (5)°, with the Sn—Cl bond lengths being 2.5704 (13) and 3.1159 (13) Å. 相似文献
9.
R. Alan Howie James L. Wardell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(7):806-807
The title compound, [SnI2(C6H11O)2], contains a six‐coordinate tin centre as a consequence of intramolecular Sn—O interactions. The Sn—O bond lengths range between 2.428 (4) and 2.439 (4) Å. 相似文献
10.
Carlos Camacho‐Camacho Monique Biesemans Ingrid Verbruggen Rudolph Willem 《应用有机金属化学》2005,19(3):343-346
The reactivity and catalytic potential of the tin salicylaldoximate cluster [(Me2Sn)2(Me2SnO)(OCH3) (HONZO)(ONZO)] ( 1 ), with HONZOH = o‐HON?CH? C6H4OH, on the acylation reaction of various alcohols with ethyl acetate is reported. The catalyst is active toward primary and unhindered secondary alcohols, but inefficient toward tertiary and secondary bulky alcohols and phenols. A possible mechanism for the transesterification reaction catalyzed by 1 , accounting for the influence of steric factors, is proposed. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
11.
In this paper, the possibility for autocatalysis in polymerization reactions is explored by introducing part of a polymerization mechanism in a model known as Brusselator. It is assumed that monomer concentration is practically constant. Four possibilities are examined: (1) a first radical propagator X, which has an isomer of position of the free electron, Y, dimerizes reversibly and this dimer catalyzes the isomerization of Y to X; (2) the radical propagator X is a polymer with a critical degree of polymerization and has an isomer of position of the free electron Y. This critical radical propagator catalyzes the conversion of Y to X; (3) any radical propagator has an isomer of position of the free electron, Y, and any polymer obtained by recombination of the radicals can catalyze the conversion of Y into its corresponding isomer X; and (4) any radical propagator with a critical degree of polymerization can catalyze the conversion of Y into its corresponding isomer. Isomorphism equations are obtained in all mechanisms, which implies the possibility of limit cycle oscillations (Brusselator model). © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 617–623, 2008 相似文献
12.
Sotiris K. Hadjikakou Mavroudis A. Demertzis Maciej Kubicki Dimitra Kovala‐Demertzi 《应用有机金属化学》2000,14(11):727-734
The complexes dimethyldi(pyrimidine‐2‐thiolato)tin(IV) ( 1 ) and diphenyldi(pyrimidine‐2‐thiolato)tin(IV) ( 2 ) have been structurally characterized by means of X‐ray crystallography. Complex 1 exhibits strong π–π stacking interactions and adduct 2 is self‐assembled via intermolecular hydrogen bonds, C H–π and π–π stacking interactions. Partial solvolysis occurs in organic solvents for 1 and 2 . Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
13.
Masood Parvez Saqib Ali Sajjad Ahmad Moazzam Hussain Bhatti Muhammad Mazhar 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(6):m334-m335
The crystal structure of catena‐poly[[tri‐n‐butyltin]‐μ‐3‐(1‐naphthylaminocarbonyl)acrylato‐κ2O1:O3], [Sn(C4H9)3(C14H10NO3)]n, is composed of polymeric chains wherein the metal center exhibits a distorted trigonal‐bipyramidal geometry, with three n‐butyl groups defining the trigonal plane [mean Sn—C 2.133 (7) Å] and the axial positions being occupied by the carboxylate O atoms of two different N‐(1‐naphthyl)maleamate ligands with inequivalent Sn—O distances [2.167 (4) and 2.457 (4) Å]. The N‐(1‐naphthyl)maleamate fragment forms an essentially planar seven‐membered ring involving an intramolecular N—H?O hydrogen bond. 相似文献
14.
The tin atom in (4‐Cl‐C6H4CH2)2Sn[S2CN(CH2CH2)2NCH3]2 is in a C2S4 skew‐trapezoidal bipyramidal geometry with the two carbon atoms being disposed over the weaker Sn? S bonds. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
15.
Dario Duca Giampaolo Barone Gianfranco La Manna Tiziana Fiore Claudia Pellerito Roberta Di Stefano Michelangelo Scopelliti Lorenzo Pellerito 《应用有机金属化学》2001,15(7):581-592
The molecular geometry, energetics and electronic charge distribution of diorgano‐ and triorgano‐tin(IV) complexes of [protoporphyrin‐IX] and [meso‐tetra(4‐carboxyphenyl)porphine] derivatives were determined at semi‐empirical and ab initio levels. To study the molecular details of the complexes, simpler molecule models were calculated by the ab initio pseudo‐potential method. The molecular properties of these complexes are essentially independent of the presence of the peripheral tin atoms. Agreement was always found among the results of the different computational approaches, as well as between the theoretical and the experimental findings on the molecular geometry of the hypothesized complexes. Interaction modes between water and the organo‐tin systems considered were affected strongly by the presence of peripheral tin atoms. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
16.
The centrosymmetric structure of bis[tris(2‐methyl‐2‐phenylpropyl)tin]piperazinyldithiocarbamate contains four‐coordinated tin and monodentate dithiocarbamate ligands. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
17.
Jos S. Casas Emilia García‐Martínez Angeles Snchez‐Gonzlez Jos Sordo Roberto Villar 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):299-300
In the title complex, [Sn(C2H5)2Cl2(C5H5N)2], the Sn atom lies on an inversion centre and is octahedrally coordinated by two Cl atoms, two ethyl C atoms and two pyridine N atoms in an all‐trans configuration. The dihedral angle between the pyridine ring and the SnNCl plane is 22.4 (2)°. 相似文献
18.
Guo‐Hai Xu Jian‐Fang Ma Ying‐Ying Liu Shun‐Li Li 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(12):m581-m583
The title compound, [CrSn(C6H5)3(C7H6NO2)3Cl][Sn(C6H5)3Cl(CH4O)], was obtained from the reaction of Ph3SnCl with the complex [Cr(C7H6NO2)3] in methanol. The structure contains [Ph3SnCl(MeOH)] (A) and [Ph3SnClCr(C7H6NO2)3] (B) molecules. In molecule A, the Sn atom of Ph3SnCl is coordinated by one methanol molecule. In molecule B, the Sn atom of Ph3SnCl is coordinated by one carboxylate O atom of [Cr(C7H6NO2)3]. Molecules A and B are connected through an O—H⋯O hydrogen bond between a carboxylate O atom and the methanol OH group. Weak C—H⋯Cl interactions and O—H⋯O hydrogen bonds extend the components of (I) into a two‐dimensional network. 相似文献
19.
Uwe‐Christoph Knig Michael Berkei Claudia Hirsch Hans Preut Terence Nigel Mitchell 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(10):e452-e453
The synthesis and X‐ray structure analysis of the title compound, [SnBr2(CH3)2(C4H9NO)2], are described. The crystal contains molecules which are separated by normal van der Waals distances. Organotin(IV) compounds are found in a variety of structural types, in which the Sn atom can, for example, be hexacoordinated. In this case, the preferred solid‐state molecular structure of the central atom is octahedral. The degree of distortion and the configuration depend on the ligands. 相似文献
20.
Strahil Berkov Francesc Viladomat Carles Codina Sergio Suárez Angel Ravelo Jaume Bastida 《Journal of mass spectrometry : JMS》2012,47(8):1065-1073
Galanthamine‐type alkaloids produced by plants of the Amaryllidaceae family are potent acetylcholinesterase inhibitors. One of them, galanthamine, has been marketed as a hydrobromide salt for the treatment of Alzheimer's disease. In the present work, gas chromatography with electron impact mass spectrometry (GC‐EIMS) fragmentation of 12 reference compounds isolated from various amaryllidaceous plants and identified by spectroscopic methods (1D and 2D nuclear magnetic resonance, circular dichroism, high‐resolution MS (HRMS) and EIMS) was studied by tandem mass spectrometry (GC‐MS/MS) and accurate mass measurements (GC‐HRMS). The studied compounds showed good peak shape and efficient GC separation with a GC‐MS fragmentation pattern similar to that obtained by direct insertion probe. With the exception of galanthamine‐N‐oxide and N‐formylnorgalanthamine, the galanthamine‐type compounds showed abundant [M]+. and [M‐H]+ ions. A typical fragmentation pattern was also observed, depending on the substituents of the skeleton. Based on the fragmentation pathways of reference compounds, three other galanthamine‐type alkaloids, including 3‐O‐(2′‐butenoyl)sanguinine, which possesses a previously unelucidated structure, were identified in Leucojum aestivum ssp. pulchelum, a species endemic to the Balearic islands. GC‐MS can be successfully applied to Amaryllidaceae plant samples in the routine screening for potentially new or known bioactive molecules, chemotaxonomy, biodiversity and identification of impurities in pharmaceutical substances. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献