Infrared picosecond transient hole-burning studies of the effect of hydrogen bonds on the vibrational line shape

Abstract

Articles you may be interested inInfrared spectroscopy of OH stretching vibrations of hydrogenbonded tropolone(H2O) n (n=1-3) and tropolone (CH3OH) n (n=1 and 2) clusters High resolution Fourier transform stimulated emission and molecular beam holeburning spectroscopy with picosecond excitation sources: Theoretical and experimental results J. Chem. Phys. 96, 179 (1992); 10.1063/1.462498Line shape of transient burned hole at the dephasing induced by slow stochastic frequency modulation AIP Conf.With infrared transient hole-burning spectroscopy we have investigated the influence of OD•••X hydrogen bonds on the vibrational line shape of O-D stretch vibrations in acid zeolites. The effect of hydrogen bonding on the line shape depends critically on the type of hydrogen bond. For hydrogen bonding in a rigid structure, the hydrogen bond determines the inhomogeneous linewidth, but the homogeneous linewidth is determined by coupling to a ϳ200 cm Ϫ1 lattice mode as concluded from the temperature dependence of the dephasing rate. When the hydrogen bond is formed with an adsorbing molecule, the coupling between the high-frequency O-D stretch vibration and the low-frequency OD•••X hydrogen-bond stretching mode does determine the homogeneous linewidth. The difference between the two systems can be explained by the different hydrogen-bond potentials. Variation of the adsorbate provides a means of obtaining conclusive information on the coupling mechanism between the high-frequency O-D stretching mode and the low-frequency OD•••X hydrogen-bond stretching mode.

Local Substructures of Water Studied by Transient Hole-Burning Spectroscopy in the Infrared: Dynamics and Temperature Dependence

“…To obtain information on molecular dynamics, time-resolved anti-Stokes Raman , or infrared techniques were demonstrated to be powerful tools. Improved versions of the pump−probe-spectroscopy with two independently tunable IR pulses , and with polarization resolution , provide detailed spectroscopic insight. In fact, transient spectroscopy on the isotopic mixture HDO in D 2 O delivered evidence for three distinct spectral components in the range 3340−3520 cm -1 at room temperature .…”

Dynamical studies of zeolitic protons and interactions with adsorbates by picosecond infrared spectroscopy

“…Knowledge of the interaction between BrOnsted hydroxyls and adsorbed species is therefore essential for a fundamental understanding of zeolite catalysis. Time-resolved infrared spectroscopy has proven to be a powerful tool in the investigation of the vibrational dynamics of the zeolite hydroxyl [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. This paper reports on a time-resolved infrared investigation of the effect of simple adsorbates on the dynamic properties of the catalytic BrOnsted hydroxyl.…”

“…These hydroxyls are known to be hydrogen-bonded to zeolite oxygen atoms (e.g. on the other side of the small pore) and vibrational lifetimes of these two differently hydrogen-bonded groups are also extremely similar [16], 44 and 48 ps, respectively. The effect of excitation with the pump-pulse on the absorption spectra is depicted in the same figure (O's in upper and lower panel), where the absorption lines (recorded with the weak probe pulses) with and without the pump pulse are presented.…”

“…The behaviour of the homogeneous linewidth for different adsorbates [15,16], leads to the schematic hydrogen-bond potentials drawn in Fig. 5.…”

Vibrational Relaxation Process of Polyatomic Molecules Adsorbed in Zeolites

“…Species adsorbed in zeolite offers a good model system for the study of vibrational relaxation process on a solid surface [1][2][3][4][5][6][7]. In the present study, the vibrational relaxation lifetimes of the CO stretching mode of Cr(CO)6 and Mo(CO)6 adsorbed on the HY, DY and NaY-type zeolites were measured at various temperature by pump-probe method using picosecond infrared laser pulses.…”