Nanosecond Laser Photolysis of N-Methylindole in Acetonitrile

Abstract

Abstract Nanosecond laser photolysis (nslp) of N-methylindole (NMI) was investigated using XeCl laser (308 nm) so that excitation is performed at the red edge of the first absorption band. At least three transient absorptions were observed i.e. those to be ascribed to Sn←S1, Tn←T1 transitions and ion-pair like species with peaks at ≈700 nm, ≈460 nm, and ≈380 nm, respectively. The transient absorptions were found to be produced by monophotonic processes. The lifetimes of the triplet state and the ion pair were determined to be ≈3.1 μs and ≈29 μs, respectively, in degassed solutions. Transient photoconductivity (tpc) measured on the same system indicated that there are both rise and decay components. Its fastest decay component of ≈26 μs, is close to that of the transient absorption ascribed to the ion pair. This result provides another example of monophotonic electron ejection through fluorescent states of aromatic amines in polar solvents, such as, acetonitrile.