d‐NMR‐Untersuchungen der behinderten Rotation am NC(X)‐Bindungsfragment. XV. Beeinflussung der Rotationsbarriere im NR2C(X)R1‐Bindungsfragment durch elektronische und sterische Substituenteneffekte
作者:
E. Kleinpeter,
S. Behrendt,
L. Beyer,
W. Dietzsch,
R. Borsdorf,
期刊:
Journal für Praktische Chemie
(WILEY Available online 1982)
卷期:
Volume 324,
issue 1
页码: 29-45
ISSN:0021-8383
年代: 1982
DOI:10.1002/prac.19823240106
出版商: WILEY‐VCH Verlag GmbH
数据来源: WILEY
摘要:
d‐N.M.R. Investigations of the Restricted Rotation at the NC(X)‐Bonding Fragment. XV. Influence of the Rotational Barrier in the NR2C(X)–R1‐Bonding Fragment by Electronic and Steric Substituent Effects.The rotational barriers ΔG≠of the restricted rotation about partial C,N‐double bonds are determined for 4 series of urea‐derivatives, and analogous compounds by complete lineshape analysis and approximation equations. Some general conclusions are drawn about the validity range of the approximations independence on the low temperature splitting Δν, the possible corrections within the margin of error and the internal temperature measurement. The dependence of the determined free enthalpies of activation about the effect of heteroatoms X, the NR2‐substituents and the electronic and steric influence of the substi
点击下载:
PDF
(868KB)
返 回