Theoretical analysis of the transition-state spectrum of the cyclooctatetraene unimolecular reaction: Three degree-of-freedom model calculations

Abstract

A three degree-of-freedom potential energy surface of the cyclooctatetraene (COT) unimolecular reaction that can describe both ring-inversion (D2d↔D2d) and double bond-alternation (D4h↔D4h) processes was constructed using complete active space self-consistent field calculations. The potential energy surface was used to simulate the experimentally measured transition-state spectrum by calculating the photodetachment spectrum of the COT anion with time-dependent wave packet formalism. The calculated spectrum reproduces the experimental result well. We also analyzed wavefunction properties at spectral peak positions to understand the COT unimolecular reaction dynamics.