Sub-Doppler resolution infrared spectroscopy of the acetylene dimer: A direct measurement of the predissociation lifetime

Abstract

Rotationally resolved, infrared predissociation spectra have been obtained for (C2H2)2 using a molecular beam apparatus in conjunction with a single mode F-center laser operating near 3300 cm -1. Several well separated bands are seen in the low resolution spectra, possibly indicating that more than one stable dimer structure exists. The high resolution spectra indicate that the widths of the individual rovibrational transitions, and hence predissociation lifetimes, depend on the band excited. The lifetimes obtained from the widths vary from 80×10 -9 to 1.6×10-9 s. © 1984 American Institute of Physics.