A-band resonance Raman spectra of 1,2-diiodoethane in cyclohexane solution.: Substituent effects on the 1-halo-2-iodoethane short-time photodissociation dynamics

Abstract

Resonance Raman spectra of 1,2-diiodoethane in cyclohexane solution have been obtained in the A-band absorption. A resonance Raman intensity analysis was done to examine the short-time photodissociation dynamics of 1,2-diiodoethane. Significant bond length and bond angle changes were found for both C-I bonds and the C-C bond as well as the CCI and HCH bond angles. Comparison of the Franck-Condon region dynamics of 1,2-diiodoethane with diiodomethane suggests that the degree of coupling of the two C-I chromophores depends on both the relative geometry of the C-I bonds and their relative separation.