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

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 D3h 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 C2v 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.