Table of Contents Author Guidelines Submit a Manuscript
E-Journal of Chemistry
Volume 9 (2012), Issue 1, Pages 193-202
http://dx.doi.org/10.1155/2012/380109

Ab Initio and DFT Studies of Conformational Properties of Heteroatom Containing Ketene Analogues and Their Comparison with the Related Cyclic Analogues

S. Zahra Sayyed-Alangi and Mohammad T. Baei

Department of Chemistry, Azadshahr Branch, Islamic Azad University, Azadshahr, Golestan, Iran

Received 29 June 2011; Accepted 27 August 2011

Copyright © 2012 Hindawi Publishing Corporation. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Minimum-energy and transition state geometries of 3-thioxoprop-2-enethial, 3-thioxoacrylaldehyde, 3-oxoprop-2-enethial, 3-selenoxoprop-2-enethial, 3-thioxoprop-2-eneselenal, 3-selenoxoprop-2-eneselenal, 3-oxoacrylaldehyde, 3-selenoxoacrylaldehyde and 3-oxoprop-2-eneselenal were calculated using HF, B3LYP and MP2 levels of theory and 6-31+G* basis set by rotation around the related -C-C- single bonds. In all of the above mentioned molecules, the s-trans conformation was obtained as the most stable conformer with the 180° dihedral angle, apart from 3-oxoprop-2-enethial and 3-thioxoprop-2-eneselenal which their s-cis conformers were appeared more stability than related to s-trans forms. Their perpendicular geometries, with torsional angles approximately 90°, were as transition state for conformational interconversion between the two global minima forms. Cyclic structures all of the above mentioned molecules were unstable than their linear forms.