Vibrational dynamics of iodine molecule and its complexes in solid krypton : towards coherent control of biomolecular reactions?

Abstract

Iodine molecule and its 1:1 complexes with xenon atom and benzene (Bz) molecule isolated in low-temperature solid krypton environment are studied experimentally using UV-vis and FTIR absorption, resonance Raman, and femtosecond coherent anti-Stokes Raman scattering (fs-CARS) measurements. Vibrational parameters for iodine molecule on the ground electronic state, dephasing rates for the ground state vibrations, dephasing mechanisms, and structures for both of the complexes are determined. In I2-Xe and I2-Bz samples, polarization interference between the different molecular species in the sample is detected in the fs-CARS signal. This interference is shown to be a useful spectroscopic tool, with which the properties of a weak signal species can be determined. The use of polarization beating as an "amplifier" is demonstrated for weak signals from both h-Xe complex and benzene molecule. The polarization beats are successfully used to find out the vibrational properties of these systems. Additionally, a general recipe for executing coherent control of a bimolecular charge-transfer reaction using a fs-CARS scheme is outlined. The experimental results obtained for the I2-Xe and I2-Bz complexes in this work are evaluated from the reaction control point of view. In the light of the experimental results, both of these complexes are considered promising candidates for bimolecular reaction control experiments.