Fluorescence polarization of a diatomic fragment following photodissociation of a triatomic precursor

Calculations are presented for the polarization anisotropy R = (I ‖ - I ⊥)/(I ‖ + 2I ⊥) of the fragment fluorescence (AB* → AB + hv) when a linear triatomic molecule (ABC) is photodissociated by a beam of linearly polarized radiation (ABC + hv → AB* + C). An expression is derived relating the polarization anisotropy R(τ) to the predissociation lifetime τ of the bent [ABC*] complex in the high-J limit. The time-averaged autocorrelation function of a prolate symmetric top, , is used to find R(τ) for the dissociation of an [ABC*] complex in a single (J, K) level.