A 13C NMR study of the structure of four cinnamic acids and their methyl esters

被引：21

作者：

Silva, AMS

Alkorta, I

Elguero, J

Silva, VLM

机构：

[1] CSIC, Inst Quim Med, E-28006 Madrid, Spain

[2] Univ Aveiro, Dept Quim, P-3810193 Aveiro, Portugal

来源：

JOURNAL OF MOLECULAR STRUCTURE | 2001年 / 595卷 / 1-3期

关键词：

cinnamic acids; cinnamic esters; solid state NMR; C-13; NMR; GIAO calculations;

D O I：

10.1016/S0022-2860(01)00486-0

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The C-13 NMR spectra, both in DMSO solution and in the solid state of four cinnamic acids (p-methoxy, p-hydroxy, p-methyl, p-chloro) and their corresponding methyl esters have been recorded. The two main results in the solid state are: (i) the only significant difference between acids and esters chemical shifts concerns the C=O group which, on average, appears at 173 ppm in the acids and 168 ppm in the esters; (ii) the signals of the ortho and meta carbons both in the acids and the esters are splitted. The two 'anomalies' disappear in DMSO solution. These observations can be rationalized using simple GIAO/B3LYP/6-31G* calculations. (C) 2001 Elsevier Science B.V. All rights reserved.

引用

页码：1 / 6

页数：6

共 18 条

[1] Ab initio (GIAO) calculations of absolute nuclear shieldings for representative compounds containing 1(2)H, 6(7)Li, 11B, 13C, 14(15)N, 17O, 19F, 29Si, 31P, 33S, and 35Cl nuclei [J].