Detection and Structural Characterization of Clusters with Ultrashort-Lived Electronically Excited States: IR Absorption Detected by Femtosecond Multiphoton Ionization

Abstract

The vibrational fingerprint of the electronically excited short-lived complex of 1-H-pyrrolo[3,2-h]quinoline:methanol was measured using femtosecond multiphoton ionization detected infrared (IR/fsMPI) spectroscopy under supersonic jet conditions. A cyclic doubly hydrogen-bonded structure of the cluster has been proven from the comparison of the measured vibrational spectrum with that calculated with density functional theory. The employed nsIR-fsUV double resonance scheme is shown to be an effective tool for structural analysis of precursors that undergo fast deactivation and/or photoreactions.