Halogeno-carbonyl and -nitrosyl complexes of the platinum metals, and their vibrational spectra

Abstract

Decarbonylation reactions of formic acid by Group VIII halide complexes have been used to prepare new halogenocarbonyl complexes of the form cis-[M(CO)₂X₄]^2– and cis-[M(CO)₃X₃]^–(M = Os or Ru; X = Cl, Br, or l), [Os(CO)X₅]^3– and [M(CO)₃X₂]₂(M = Os or Ru; X = Cl or Br), [M(CO)X₅]^2–(M = lr, Rh, or Ru; X = Cl or Br), and [Pt(CO)X₃]^–(X = Cl or Br). A number of triphenylphosphine derivatives of these products were also made, e.g. M(CO)₂X₂(PPh₃)₂(M = Os or Ru; X = Cl or Br). The vibrational spectra of the halogenocarbonyls were measured and assignments of fundamental modes proposed. The spectra of pentahalogeno-carbonyl and -nitrosyl species were compared and ¹³C and ¹⁵N substitution used to confirm the assignments.