| The chemistry of metal clusters is a fascinating and expanding area of research. During the last three decades, the study of metal clusters and in particular transition metal clusters has been the subject of numerous experimental and theoretical investigations. The desire to understand the frontier between molecular chemistry and solid state physics, as well as to gain new insight into the chemical properties of the metal surfaces used in heterogeneous catalysis is one of the motivations for the extensive work done on metal clusters.; Absorption and Resonance Raman spectroscopy has been employed to interrogate mass-selected metal clusters in argon matrices. With the CCNY metal cluster deposition source, metal cluster cations (produced by bombardment) are mass selected using a velocity Wien Filter, and then co-deposited with rare gas on a cold window in the presence of low energy electrons. Neutralized cluster samples are interrogated by absorption, excitation, fluorescence and Raman spectroscopy. Good quality Raman spectra of Heteronuclear Clusters such as dimers of Al2, Mo2 and trimers of Cr3, Mo 3, and tetramer of Sc are reported. At the same time, investigation of heteronuclear clusters resulted in reports on VCo, VFe, CuAg, CrFe, and TiCu3. The information about the geometry, electronic and vibrational structures, dissociation energies and force constants are determined from resonance Raman spectroscopy, absorption and Raman excitation profiles which turned out to be a very useful and fruitful method to assign all the optical transitions involved in each metal clusters. In fact Raman excitation profiles might even be a more sensitive method for obtaining cluster absorption spectra than direct measurements. |
