Dynamic studies of charge-separated-state enhancement of the optical nonlinearity of a porphyrin heterodimer

Light‐induced enhancement of the third‐order nonlinear optical susceptibility of a heterodimer consisting of two different porphyrin monomers, a zinctetra(4‐sulfonatophenyl)porphyrin and a zinctetra(4‐N‐methyl‐pyridyl)porphyrin, was observed when the sample was optically pumped by a 30 ps, 532 nm pump pulse. The temporal behavior of the enhancement was studied. It was found that the enhancement was due predominantly to the population of the charge‐separated state with a large electronic third‐order nonlinear optical susceptibility