Infrared spectra of acetylene-water complexes: C2D2-H2O, C2D2-HDO, and C2D2-D2O

Infrared spectra of C2D2-water complexes are studied in the 4.1 mu m region of the C2D2 v(3) fundamental band using a tunable diode laser source to probe a pulsed supersonic slit jet. Relatively large vibrational red shifts (-27.7 to -28.0 cm(-1)) are observed which are more easily interpretable than for the analogous C2H2 vibration thanks to the absence of Fermi resonance effects for C2D2. Noticeable homogeneous line broadening leads to estimates of upper state predissociation lifetimes of about 0.5, 0.9 and 1.1 ns for C2D2-H2O, -HDO, and -D2O, respectively. Transitions involving K-a = 0 and 1 levels are observed for C2D2-HDO, but there is a puzzling absence of K-a = 1 for C2D2-H2O and C2D2-D2O. (C) 2011 Elsevier Inc. All rights reserved.