THE EFFECT OF HYDROGEN BONDING ON THE LOWEST $n\pi^{\ast}$ TRANSITION OF PYRIMIDINE IN A SUPERSONIC JET

Author Institution: Department of Chemistry, Tufts University; Department of Chemistry, Williams CollegeWe have attempted to measure the laser induced fluorescence excitation spectrum of several hydrogen bonded complexes of pyrimidine in a supersonic jet. No evidence of complex formation with water was obtained. Seeding the driver gas with hexafluoroisopropyl alcohol caused the sharp vibronic bands of pyrimidine to disappear. Intermediate concentrations of alcohol caused the appearance of a broad, structureless feature beginning about $4000cm^{-1}$ above the origin of pyrimidine at $31070cm^{-1}$, which continued to rise to the limit of our measurements at 275 nm. Addition of excess alcohol suppresses this feature leading us to conclude that it is the spectrum of singly hydrogen bonded pyrimidine. A Comparison of these data with solution spectra will be presented