Raman spectra of mass-selected cobalt dimers in argon matrices

We report absorption and Raman spectra for cobalt dimers in an argon matrix prepared by the mass-selected ion deposition technique. A weak dimer absorption band was found between 425 and 485 nm. Resonance Raman spectra (obtained by exciting between 457.9–488.0 nm) give ωe″= 296.8(54) cm−1 with ωexe″ = 2.2(8) cm−1. The dicobalt data are discussed in terms of results from recent photodetachment experiments which suggest a changeover from d–d bonding to s–s bonding along the series Fe2→Cu2.