Complex formation, rearrangement, and reaction in PhOH++ND3: Vibrational mode effects, recoil velocities, and ab initio studies

Vibrationally mode-selected phenol cations (C6H5OH+ and C6D5OH+) were react ed with ND3 in a guided-ion-beam instrument. Integral cross sections and re coil velocity distributions are reported as a function of collision energy and vibrational state. Three reactions are observed. A small signal is foun d for the [PhOH:ND3](+) adduct at low total energies, indicating the format ion of a very long-lived complex. The major reaction is H/D exchange, gener ating PhOD++ND2H. Exchange is similar to 40% efficient at low energies, str ongly inhibited by collision energy, and strongly enhanced by excitation of PhOH+ vibrations. Recoil velocity distributions suggest that H/D exchange proceeds through a statistical complex at all energies. A precursor complex is invoked to explain the energy and vibrational state dependence. The end oergic proton transfer reaction is a minor channel at all energies, with dy namics intermediate between the direct and complex limits. Quantum chemistr y and RRKM calculations are reported, providing an additional mechanistic i nsight. (C) 2000 American Institute of Physics. [S0021-9606(00)01634-2].