Twisted push-pull ethylenes

被引：8

作者：

Veedu, Rakesh Naduvile ^{[1
]}

Bernhardt, Paul V. ^{[1
]}

Koch, Rainer ^{[2
]}

Wentrup, Curt ^{[1
]}

机构：

[1] Univ Queensland, Sch Mol & Microbial Sci, Brisbane, Qld 4072, Australia

[2] Carl VonOssietzky Univ Oldenburg, Inst Reine & Angew Chem, D-26111 Oldenburg, Germany

来源：

AUSTRALIAN JOURNAL OF CHEMISTRY | 2008年 / 61卷 / 10期

基金：

澳大利亚研究理事会;

关键词：

D O I：

10.1071/CH08277

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

As determined by X-ray crystallography, Meldrum's acid derivatives 5, 6, and 8 feature dihedral angles around the central C5=C7 double bond of 14-35 degrees, whereas for the anion 9 this angle is 90 degrees. Density functional theory and MP2 calculations are in agreement with the experimental X-ray data for compounds 5-8, but for anion 9 an angle of only similar to 65 degrees is predicted. It is concluded that a part of the torsion is due to packing forces in the crystal. It is further concluded that these molecules undergo rapid rotation about the central CC bonds at room temperature (calculated activation barriers 5-14 kcal mol(-1)).

引用

页码：805 / 812

页数：8

共 43 条

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