Raman spectroscopy of mass-selected metal clusters.

摘要

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 codeposited 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. Following previous work on transition metal clusters, we focused on the IIIB group and lanthanide dimers. Good quality Raman spectra of Y ₂, La₂, Ce₂, Pr₂, Nd₂, Gd ₂, Tb₂, Lu₂ are reported. At the same time, investigation on triatomic clusters resulted in reports on Rh₃, Ta₃, and Ru₃. Electronic transitions have been assigned with little ambiguity as to spectral carrier. Vibrational parameters were obtained for the first time. These results provided bonding properties and structural information. They give us further understanding of bonding character.