Stereochemical non-rigidity of N-(dimethylhalogenosilylmethyl)-N-(1-phenylethyl)acetamides in solutions

被引：21

作者：

Negrebetsky, VV ^{[1
]}

Shipov, AG ^{[1
]}

Kramarova, EP ^{[1
]}

Negrebetsky, VV ^{[1
]}

Baukov, YI ^{[1
]}

机构：

[1] RUSSIAN STATE MED UNIV,MOSCOW 117869,RUSSIA

来源：

JOURNAL OF ORGANOMETALLIC CHEMISTRY | 1997年 / 530卷 / 1-2期

基金：

俄罗斯基础研究基金会;

关键词：

pentacoordinated organosilicon compounds; intramolecular coordination; intermolecular coordination; dynamic NMR; permutational isomerization;

D O I：

10.1016/S0022-328X(96)06594-1

中图分类号：

O61 [无机化学];

学科分类号：

070301 ; 081704 ;

摘要：

The structure and dynamic behavior of (O-Si)-chelate N-(dimethylhalogenosilyl)methyl acetamides of the type MeC(O)N(CH(Ph)Me)CH2SiMe2 X, where X = F, Cl, Br with the OSiC3X coordination set, were studied by multinuclear (H-1, C-13, O-17, Si-19) and dynamic H-1 NMR spectroscopy. Ligand permutation at silicon was detected. The observed influence of the solvent, nucleofugacity of the X substituent and the external nucleophile on the calculated values of the free energies of activation testify to the dissociative and/or associative mechanisms of the process, but including the stages in which the regular (pseudo-rotation or 'turnstile') mechanism takes place. At lower temperatures (up to -90 degrees C) the H-1, C-13, Si-29 NMR spectra of N-(dimethylchlorosilyl)methyl acetamide contain the signals of two species of unequal intensity. This effect was explained by an equilibrium between monomers containing the intramolecular O --> Si bond and dimers with a hexacoordinate silicon and the bridging chlorine atoms.

引用

页码：1 / 12

页数：12

共 36 条

[1] NMR-STUDY OF (AROYLOXYMETHYL)TRIFLUOROSILANES [J].