The ab initio calculations on the lower excited states of short-chain polyenals

Author(s):
Ros, M.; Groenen, E.J.J. (0000-0001-7530-9211); Hemert, M.C. van
Published
1992
Publication type
Article / Letter to editor

Abstract

The lower excited states of the planar all-trans isomers of crotonaldehyde, hexadienal, and octatrienal have been investigated by multi-reference single and double excitation configuration interaction (MRD-CI) calculations. For crotonaldehyde we find both the lowest excited singlet state S1 and the lowest triplet state T0 to be n-pi* in nature; for hexadienal and octatrienal S1 is n-pi* and T0 is pi-pi* in nature. Bond-order reversal stabilizes the lower excited states and destabilizes the ground state. The pi-pi* states decrease more in energy than the n-pi* states upon lengthening the polyenal. We calculate the radiative lifetime of the 3-pi-pi* state in the ground-state geometry to vary from 35 ms for crotonaldehyde to 75 s for octatrienal and explain the absence of phosphorescence for polyenals.

Date issued
1992-08-12
Language
English
Publisher
AMER CHEMICAL SOC
Is part of
Journal of the American Chemical Society (1992), Vol. 114, no. 17, p. 6820-6827
hdl
1887/3590352
doi
10.1021/ja00043a030
URL
https://pubs.acs.org/doi/abs/10.1021/ja00043a030