SYMMETRIES OF HYDROGEN-BONDED ENOL FORMS OF DIKETONES AS DETERMINED BY X-RAY PHOTOELECTRON-SPECTROSCOPY

被引：152

作者：

BROWN, RS ^{[1
]}

TSE, A ^{[1
]}

NAKASHIMA, T ^{[1
]}

HADDON, RC ^{[1
]}

机构：

[1] BELL TEL LABS INC,MURRAY HILL,NJ 07974

来源：

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | 1979年 / 101卷 / 12期

关键词：

D O I：

10.1021/ja00506a003

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The O1S ionization regions of malonaldehyde (1a), hexafluoroacetylacetone (1c), tropoione (3a), 9-hydroxyphenalenone (4), and 6-hydroxy-2-formylfulvene (5) all show two dominant ionizations arising from oxygens made inequivalent by virtue of an asymmetric H bond. 1H NMR studies of the transoid enol form of malonaldehyde in deuterated ethanol show that the apparent symmetry of the molecule on the NMR time scale cannot be explained by keto-enol equilibria since this latter process is far too slow. Additional NMR studies of the intramolecularly H bonded cisoid form of malonaldehyde in CFCI3- CD2CI2 solvents indicate that the upper limit for the effective barrier to interconversion of the Cs forms via the C2v form is no greater than 6 kcal/mol. Similar results were obtained with deuterated malonaldehyde. © 1979, American Chemical Society. All rights reserved.

引用

页码：3157 / 3162

页数：6

共 55 条

[1] PROTON, DEUTERIUM, AND TRITIUM NUCLEAR MAGNETIC-RESONANCE OF INTRA-MOLECULAR HYDROGEN-BONDS - ISOTOPE EFFECTS AND SHAPE OF POTENTIAL-ENERGY FUNCTION [J].