Femtosecond time-resolved measurement of LDS698 molecular processes under high pressure

Femtosecond time-resolved measurements provide a means to understand high pressure effects on ultrafast molecular processes. We report here a method of transient absorption spectroscopy in conjunction with diamond anvil cells for investigating molecular energy relaxation of solidified LDS698 (pyridine, C19H23N2O4Cl) molecular solution. The pressure effect on the intermolecular energy relaxation is significant with increasing rate constant. The results are satisfactorily interpreted in terms of the intermolecular harmonic oscillator model with the anharmonic correction through surrounding thermal diffusion. This technique opens an approach to study molecular energy relaxation and other ultrafast processes of matter under high pressure. (C) 2008 American Institute of Physics.