Formation and photofragmentation properties of isolated aromatic amino acid-silver cluster hybrids

The formation of isolated [(Trp-2H)+Ag(9)](+) and [(Tyr-2H)+Ag(9)](+) amino-acid-Ag(9) hybrids is reported. The photofragmentation yields of the aromatic amino acid-silver cluster hybrids, as well as those of the protonated tryptophan and tyrosine molecules (Trp+H](+) and [Tyr+H](+)) have been recorded. The fragmentation yields of the complexes are higher than the yields for [[Trp+H](+) and [Tyr+H](+) and present an extension of the fragmentation on the red side of the spectrum. The photofragmentation spectrum Of [Trp+Ag(9)](+) was recently reported [Mitric et al., J. Chem. Phys. 127, 134301. (2007)]. While the optical spectra of substituted [(Trp-2H)+Ag(9)](+) and non-substituted [Trp+Ag(9)](+) complexes are very similar, a strong modification of the fragmentation channels between the two complexes is observed. The fragmentation channels are sensitive to the type of bonding in aromatic amino acid-silver cluster hybrids and can be used as fingerprints of structures.