Raman, resonance Raman, and infrared spectroscopic study of complexes containing copper(I)–tetrathio-molybdate(VI) and -tungstate(VI) anions

Abstract

Raman, resonance Raman at ca. 80 K, and infrared spectra of thirteen ions of the type [MS₄-(CuL)_n]^2–(M = Mo or W; L = CN, SPh, SC₆H₄Me-4, Cl, or Br; n= 1–4) are reported. Totally symmetric ν(Mo–S) and ν(W–S) stretches are easily identified as giving rise to the most intense bands in the Raman and particularly resonance Raman spectra of the complexes. The pattern (i.e. the number of bands, their wavenumbers and relative intensities) observed in the ν(Mo–S) region (415–496 cm^–1) is distinctive for the number of Cu^I ions co-ordinated to [MoS₄]^2–.