PIRATE - a picosecond time resolved IR spectrometer

PIRATE (picosecond infrared absorption and transient excitation) is a recently developed solid state laser facility offering tunability into the mid-infrared region (down to 1000 cm^-1) for time-resolved infrared (TRIR) spectroscopy. It is used to study the energetic properties, structure and reactivity of short lived (picosecond & femtosecond) intermediates formed during the course of photophysical and photochemical processes. The presentation will briefly describe the PIRATE system and give recent highlights from investigations on solvation and hydrogen bonding within excited molecular states to illustrate the performance of the ps-TRIR spectrometer. This study has now progressed to look at the dynamics of the solvation of excited states and in particular the formation of hydrogen bonds to electronically excited charge transfer states such as for the intramolecular charge transfer reaction of DMABN by monitoring rapid frequency shifts of the cyano stretch of this molecule by TRIR. this work shows the first direct observation of hydrogen bond formation in a molecular excited state.