作者:T. Yabe、S. Sankararaman、Jay K. Kochi
DOI:10.1021/j100164a002
日期:1991.5
The contact ion pairs [An+, T-] and [BA+, T-] (T- = trinitromethide anion) are spontaneously generated (< 10 ps) when the charge-transfer complexes of anthracene (An) and bromoanthracene (BA) with tetranitromethane (TNO2) are irradiated with a 532-nm laser pulse. The first-order rate constants for the subsequent relaxation (k2) of these prototypal contact ion pairs (CIP) to the solvent-separated ion pairs (SSIP) and annihilation (k1) to the sigma-adducts are strongly dependent on solvent polarity (acetonitrile, hexane, benzene, dichloromethane, and chloroform). Quantitative analysis also reveals the ionic exchange (k(x)) of the contact ion pairs with added salt, both the innocuous Bu4N+ClO4- and the common-ion Bu4N+T-, to occur in direct competition with k1 and k2 for CIP lifetimes of > 700 ps.