Proton nuclear magnetic resonance spectroscopy:: Significant barriers to rotation about N-N bonds in 3-acylaminoquinazolin-4(3H)-one derivatives

被引：12

作者：

El-Hiti, GA ^{[1
]}

机构：

[1] Tanta Univ, Fac Sci, Dept Chem, Tanta, Egypt

来源：

SPECTROSCOPY LETTERS | 1999年 / 32卷 / 04期

关键词：

quinazolin-4(3H)-ones; H-1 NMR spectra; hindered rotation; free energy of activation; stereochemical process; chiral axis; orthogonal conformation; coalescence temperatures;

D O I：

10.1080/00387019909350016

中图分类号：

O433 [光谱学];

学科分类号：

0703 ; 070302 ;

摘要：

The proton NMR spectra of several 3-acylaminoquinazolin-4(3H)-one derivatives have been studied as a function of temperature. The changes, which were found to occur in the spectra at high temperatures, are discussed in terms of hindered rotation about the nitrogen-nitrogen bond. The free energies of activation for the rate-determining stereochemical process were calculated to be as high as (14.7 similar to 20.6 Kcal mol(-1)) for hydrazine derivatives.

引用

页码：671 / 677

页数：7

共 35 条

[1] CONFORMATIONS OF TETRA- AND HEXAHYDROPYRIDAZINES . SLOW RING INVERSION AND SLOW NITROGEN INVERSION [J].