TRANSIENT HOLE-BURNING IN THE INFRARED IN AN ETHANOL SOLUTION

Transient hole burning in the oligomer region of the DH-stretching mod e of ethanol dissolved in carbon tetrachloride is demonstrated, using two-color IR spectroscopy with excitation and probing pulses of 2 and 1 ps, respectively. The observed inhomogeneous broadening of the oligo mer band is explained via local disorder of the hydrogen bonds. The li fetime of the spectral holes is estimated to be approximately 1 ps, pr oviding evidence for rapid spectral relaxation and/or migration of vib rational excitation. The observed time evolution of excited state abso rption from v = 1 to v = 2 levels yields the v = 1 population lifetime of 1.4 +/- 0.3 ps. Breaking of the ethanol rings or chains as indicat ed by longer-lived induced absorption in the dimer/trimer region aroun d 3450 cm(-1) and further spectral features are reported.