Abstract

INTERPRETATION & STUDIES OF THE ABSORPTION SPECTRA OF ANNULENES AND DEVELOPING A NEW METHOD FOR CLASSROOM EXPERIMENTAL STUDIES BY USE OF ELECTRON IN A RING MODEL.

Jayprakash S. Chauhan and Ajit V. Pandya*

Abstract

Mono Cyclic Polyenes are the long chain cyclic molecules derived from the polymerization of acetylene. These are cyclic conjugated oligomers, which posses alternate double bonds. The π - electrons are completely delocalized over the entire cyclic molecule which can be considered as electrons in a ring. We have applied electron in a ring model to interpret the electronic absorption spectra and to study other properties of few of the synthetic annulenes.. In addition, this paper describes an experiment which may be useful for graduate and undergraduate students. This idea may expose students to the application part of quantum chemistry. The results of the quantum mechanical model indicates higher error for smaller annulenes where as error decreases as the circumference increases.

Keywords: Annulenes, electron in ring model, delocalization, conjugation, absorbance.