Mass Resolved Laser Spectroscopy of Microsolvated R-(+)-1-Phenyl-1-propanol: A Chiral Molecule of Biological Interest.

The effects of micro-solvation on the radical cation of R-(+)-1-phenyl-1-propanol, have been investigated. The energy thresholds of the homolytic C.alpha.-C.beta. bond breaking of R-(+)-1-phenyl-1-propanol radical cation, its mono-hydrated cluster, and its clusters with (2R,3R)-(-)-2,3-butanediol and (2S,3S)-(+)-2,3-butanediol have been studied by two color resonant two photon ionization and photodissocn. The barrier of the C.alpha.-C.beta. fragmentation is appreciably higher for the unsolvated mol. ion than for its adducts with solvent mols. Marked differences in the Et loss fragmentation energy are obsd. for clusters with water and with the two diols. In particular, the homochiral cluster with (2R,3R)-(-)-2,3-butanediol exhibits a fragmentation barrier higher than that of the corresponding heterochiral adduct with (2S,3S)-(+)-2,3-butanediol. At variance with the water adduct, the fragmentation of the covalent C.alpha.-C.beta. bond in the diol-clusters is energetically preferred to the loss of solvent.