Abstract
We obtain an accurate long-time solution for the diffusive kinetics of an excited geminate pair dissociating reversibly in solution, where the excited-state lifetimes of the bound and unbound states may be nonequal. We analyze the long-time asymptotic behavior, finding a transition between two types of behaviors. In region A, the excited bound pair decays as t-3/2exp(-t/τ′0), where τ′0 is the lifetime of the unbound state. In region AB, the decay is a pure exponential. At the critical value of the parameters where the transition occurs, we find a t-1/2exp(-t/τ′0) decay. These predictions are tested against an exact numerical solution of the corresponding coupled partial differential equations. For region A, we supply an experimental example involving time-resolved excited-state proton transfer from 5-cyano-2-naphthol to dimethyl sulfoxide.
Original language | English |
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Pages (from-to) | 2164-2174 |
Number of pages | 11 |
Journal | Journal of Chemical Physics |
Volume | 110 |
Issue number | 4 |
DOIs | |
State | Published - 22 Jan 1999 |