Conformation-selective photoionization of covalently-linked diaryl compounds: Excimer-mediated one-color two-photon ionization in seeded beams of 1,3-diphenylpropane Excited stateselected transition metal cations from onecolor UV multiphoton ionization A one-color photolysis-ionization study of the photodissociation of hydrazoic acid near 283 nm has been carried out. The N2 and NH(a I~) products have both been detected in a state-specific manner by resonance-enhanced multiphoton ionization (REMPI) in a time-of-flight mass spectrometer. The N2 fragments were observed in the v = 0 vibrational mainfold and were found to be highly rotationally excited, with an average rotational excitation of 0.79 eV. The p-J correlation parameter J