Frequency-dependent vibrational population relaxation time of the OH stretching mode in liquid water

Vibrational population relaxation of hydrogen-bonded phenol complexes in solution: Investigation by ultrafast infrared pump–probe spectroscopy

“…For HOD in D 2 O, the lifetime of the OH stretching mode was reported to be frequency-dependent [36], with the relaxation time varying from 0.5 ps at 3270 cm À1 to 1.0 ps at 3600 cm À1 . In contrast, for HOD in H 2 O, vibrational population relaxation for the OD stretching mode was reported by Steinel et al to be 1.45 ps, which is frequency-independent [37].…”

“…To the best of our knowledge, there have as yet been no ultrafast time-resolved IR studies probing the OH stretching modes of hydrogen-bonded phenol complexes in the condensed phase. In water, the dependence of relaxation rates on probe frequency is different for the OH and OD stretching modes of HOD in D 2 O and H 2 O [36,37]. Comparison of the vibrational dynamics of the OH and OD stretching modes in hydrogen-bonded systems provides useful information for understanding the spectral diffusion process and the pathway of vibrational population relaxation.…”

Vibrational Line Shapes, Spectral Diffusion, and Hydrogen Bonding in Liquid Water

“…The shoulder in the Raman spectra has been attributed to HOD molecules lacking a hydrogen (H) bond to the H atom [15][16][17][18][19]. Two-and three-pulse echo [10,[20][21][22][23][24][25][26] and other ultrafast [16,17,[27][28][29][30][31][32][33][34][35][36][37] experiments have also been performed on this system. One such integrated three-pulse echo peak shift experiment [10] shows an interesting oscillation at short times (with a period of about 180 fs) that has been attributed to underdamped H-bond stretching [15,23,[38][39][40][41][42], and a long-time decay on a 1.4-ps time scale that is thought to be due to dynamics of H-bond rearrangement [15,16,24,38,40,42,43].…”

Few-cycle mid-infrared pulse generation, characterization, and coherent propagation in optically dense media

“…[20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] However, given the small transition dipole moments of typical vibrational transitions compared to electronic transitions, nonlinear vibrational spectroscopic signals tend to be small relative to their optical counterparts. In addition to requiring higher energy pulses, these studies often employ samples with optical densities ͑O.D.͒ of ϳ1, significantly larger than the O.D.…”