Vibrational Dephasing Mechanisms in Hydrogen-Bonded Systems

With transient IR hole-burning spectroscopy we observe large variations in the homogeneous linewidth of the ${\nu }_s$(O-D) stretch vibration of differently hydrogen-bonded surface hydroxyls in zeolite catalysts. The linewidth is very sensitive to the frequency of the ${\nu }_{\sigma }(\mathrm{OD}\cdots X$) hydrogen-bond vibration. By varying this frequency we obtain conclusive information on the coupling between the ${\nu }_s$(O-D) and the ${\nu }_{\sigma }(\mathrm{OD}\cdots X$) modes.