Complexes of alkyl and aryl cyanides. Part VI. The vibrational spectra of MX2•2RCN, where M = Pd or Pt, X = Cl or Br, and R = Me or Ph, and the assignment of the metal–nitrogen stretching frequency

A careful examination of the Raman and infrared spectra of the crystalline planar complexes cis-and trans-MX2•2RCN, where M = Pd or Pt, X = Cl or Br, and R = Me or Ph, reveals intense absorption bands in the 125–80 cm−1 region which can be assigned to modes involving stretching of the metal–nitrogen bonds. Alternative assignments for v(M—N) are also discussed. These results are compared with those for other metal halide – RCN systems. The complexes trans-PtBr2•2RCN are described for the first time.