ELECTRONIC-SPECTRA AND PROTON-TRANSFER IN THE PHENOL (NH3)N CLUSTERS IN ARGON MATRICES

Absorption, fluorescence, phosphorescence and fluorescence- and phosphorescence-excitation spectra are recorded for the phenol/ammonia (PHI-OH/NH3) system in argon matrices. The spectrum corresponding to the free PHI-OH molecules, to PHI-OH..(NH3) complexes, to PHI-OH..(NH3)2 and large PHI-OH..(NH3)n (n greater-than-or-equal-to 3) clusters are identified. It is shown that the ionic form: PHI-O-..H(NH3)n+ corresponds to the energy minimum in n greater-than-or-equal-to 3 clusters in the S1 state, while in the S0 and T1 states it appears only in very large PHI-OH..(NH3)n clusters formed in pure ammonia and mixed NH3/Ar matrices with a high ammonia content. The results are compared to those obtained for free phenol-ammonia clusters formed in a supersonic expansion.