Accession Number : ADA269133

Title :   Proton Transfer Dynamics and Cluster Ion Fragmentation in Phenol/Ammonia CLusters.

Descriptive Note : Technical rept.,

Corporate Author : COLORADO STATE UNIV FORT COLLINS DEPT OF BIOCHEMISTRY

Personal Author(s) : Hineman, M. ; Kelley, D. F. ; Bernstein, E. R.

Report Date : 24 AUG 1993

Pagination or Media Count : 21

Abstract : Excited-state proton transfer dynamics are reported for the phenol(NH3)n cluster system. Excited state proton transfer is shown to occur for this system by isotopic substitution of the hydroxyl proton and ammonia protons. The observed dynamics slow from 80 ps to 600 ps upon cluster deuteration. The effects of cluster vibrational energy and ammonia concentration in the expansion gas are also studied. The results of these experiments are compared with a previous study which used a single excitation energy and varied ionization energy. Our experiments indicate that a significant amount of cluster ion fragmentation occurs for this system and caution must be exercised in assigning the decays observed in a given ion mass channel to a particular parent cluster. Due to the difficulties of associating a given decay curve with a cluster of particular mass, a previously proposed model of proton transfer in isolated clusters which details the effect of cluster vibrational energy on the proton transfer rate, cannot be applied to the phenol/ammonia system.

Descriptors :   *AMMONIA, *DYNAMICS, *FRAGMENTATION, *IONS, *PHENOLS, *PROTONS, *TRANSFER, CHANNELS, DECAY, ENERGY, EXCITATION, EXPANSION, IONIZATION, MASS, MODELS, RATES, ISOTOPES, SUBSTITUTION REACTIONS, HYDROXYL RADICALS, DEUTERIUM, VIBRATION, GASES.

Subject Categories : Physical Chemistry
      Organic Chemistry
      Atomic and Molecular Physics and Spectroscopy
      Nuclear Physics & Elementary Particle Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE