Multiphoton dissociation/ionization of benzene, pyridine, and diazabenzenes. Detection of an atomic carbon transition

Abstract

Multiphoton processes in benzene, pyridine, and the diazabenzenes with ∼10 ns, 0.4–2.5 mJ pulsed laser light in the 336–347 nm range, produced resonantly enhanced molecular ions as well as neutral carbon atoms. The carbon atoms were detected by subsequent two-photon resonant (...2p2 1D2→2hν ...2p3p 1P1) three-photon ionization at 340.93 nm. MPI resonances due to vibrations of the 3p Rydberg state appeared in the spectra of pyrazine and pyrimidine, as well as a probable member of the first singlet→triplet band in pyrimidine.