LIQUID, GLASS, AND PROTEIN VIBRATIONAL DYNAMICS - INFRARED VIBRATIONAL ECHO EXPERIMENTS

The vibrational dynamics of polyatomic molecules in polyatomic liquids , glasses and proteins are examined using picosecond infrared vibratio nal echo experiments and pump-probe experiments as a function of tempe rature. The vibrational echo experiments measure T-2, the homogenous d ephasing time, while the pump-probe experiments measure the vibrationa l lifetime, T-1, and orientational relaxation dynamics. By combining t hese measurements, a complete analysis of vibrational dynamics is obta ined. Systems studied include tungsten hexacarbonyl in the organic gla sses 2-methylpentane, 2-methyltetrahydrofuran, and dibutylphthalate, a nd wild-type and mutant myoglobin-CO in glycerol/water.