A Forgotten Channel in the Excited State Dynamics of Phenol-(Ammonia)n Clusters: Hydrogen Transfer

G. A. PINO; G. GRÉGOIRE; C. DEDONDER-LARDEUX; C. JOUVET; S. MARTRENCHARD; D. SOLGADI

PHYSICAL CHEMISTRY CHEMICAL PHYSICS

ROYAL SOC CHEMISTRY

Año: 2000 vol. 2 p. 893 - 900

1463-9076

Small phenol(NH3)n clusters have been studied through two-color two-photon and one-photon VUV ionization, in order to disentangle the contributions of various dissociation or reaction paths in the excited and ionic states. The most striking result of the two-color experiment is that (NH4)(NH3)n-1 fragments are  observed with large delays (up to a few hundred nanoseconds) between the excitation and ionization lasers, whereas these same fragments are not observed in the VUV one-photon ionization experiment. In order to account for these findings, a new deactivation channel in the excited state of phenol(NH3)n clusters has to be introduced: the hydrogen atom transfer PhOH(S1)(NH3)3 -> PhO + NH4(NH3)n-1 In this case, the delayed NH4(NH3)n-1 signals correspond to direct ionization of the clusters produced in the excited state.