Raman spectra of mass-selected nickel dimers in argon matrices

The absorption and Raman spectra for nickel dimers in an argon matrix prepared by the mass-selected ion deposition technique have been measured. A weak dimer absorption band is centered around 480 nm. Resonance Raman spectra obtained from exciting into the dimer 480 nm band show a vibrational progression for which ωe=259.2±3.0 cm−1 with ωexe=1.9±0.7 cm−1. The dinickel Raman spectra are discussed in terms of isotopic shifts, as well as the changeover from d–d bonding to s–s bonding along the series Fe2→Cu2.