Global and local aromaticity of linear and angular polyacenes

被引：92

作者：

Cyranski, MK ^{[1
]}

Stepien, BT ^{[1
]}

Krygowski, TM ^{[1
]}

机构：

[1] Univ Warsaw, Dept Chem, PL-02093 Warsaw, Poland

来源：

TETRAHEDRON | 2000年 / 56卷 / 49期

关键词：

aromaticity; polyacenes; Cohen-Benson ASE; NICS; HOMA;

D O I：

10.1016/S0040-4020(00)00919-4

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Ab initio (B3LYP/6-311G**) optimisation of seven linear and five angular polyacenes gave us an opportunity to study aromaticity in terms of HOMA index and its components EN and GEO, the energy of the carbon skeleton of these hydrocarbons was calculated from CC bond lengths. Independently, the Cohen-Benson group additivity values were used to estimate the thermochemical aromatic stabilisation energy (ASE). For individual rings the NICS values were computed and compared with HOMA. An increase of size of both linear and angular polyacenes is associated with a substantial decrease in their aromaticity, with a greater decrease for the linear polyacenes. This is well documented by both HOMA and Cohen-Benson ASE. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：9663 / 9667

页数：5