Infrared spectra of trimetal dodecacarbonyl species in frozen gas matrices at 20 K

Abstract

Infrared spectra are reported for Fe₃(CO)₁₂, Ru₃(CO)₁₂, Os₃(CO)₁₂, and Ru₃(CO)₁₀(NO)₂ in argon and nitrogen matrices at 20 K. There are strong similarities between the matrix and solution spectrum of Ru₃(CO)₁₂, or Os₃(CO)₁₂, or Ru₃(CO)₁₀(NO)₂ and it appears that for M₃(CO)₁₂(M = Ru, Os) the isolated molecules are somewhat distorted from an idealized D_3h symmetry, with greater distortions in argon than in nitrogen. The matrix spectrum of Fe₃(CO)₁₂ is completely different from the solution spectrum and indicates that the isolated molecule has the doubly bridged C_2v structure observed in the solid. The results strengthen the hypothesis that Fe₃(CO)₁₂ is present in solution with a structure different from that in the solid.