Interconversions ofZ-1,3,5-hexatriene conformers: A theoretical study

Abstract

A two-dimensional potential-energy surface was calculated for the ground state of Z-1,3,5-hexatriene in order to study the conformational relaxation after its photochemical formation from 1,3-cyclohexadiene. The potential-energy surface was scanned along both CC single bond torsional angles while all other internal coordinates were optimized at the DFT/B3LYP/6-31G** level. The three conformational minima corresponding to cZc-, tZc-, and tZt-hexatriene as well as four transition states were localized and characterized. The various interconnecting reaction pathways were determined by IRC calculations. The rate constants obtained from the calculated activation barriers are compared to experimental results. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 72: 295–305, 1999