Resonance Raman spectra of complex vapor phase compounds formed by reacting ''acidic'' gases (A/sub 2/X/sub 6/ = Al/sub 2/Cl/sub 6/, Al/sub 2/Br/sub 6/, In/sub 2/Cl/sub 6/) with metal halides have been measured. Spectra obtained from equilibrium vapor mixtures of A/sub 2/X/sub 6/ over solid MX/sub 2/ (= PdCl/sub 2/, PdBr/sub 2/, CuCl/sub 2/, CoBr/sub 2/, TiCl/sub 2/, FeCl/sub 2/, NiCl/sub 2/, PtCl/sub 2/) were a superposition of the A/sub 2/X/sub 6/-AX/sub 3/ bands and in few cases of new resonance-enhanced polarized bands due to MA/sub 2/X/sub 8/ and/or MAX/sub 5/ complexes. At temperatures above 800/sup 0/K, characteristic bands due to MX/sub 2/(g) (M = Fe, Co, Ni, Cu, Zn) and M/sub 2/X/sub 4/(g) (M = Cu) were observed. The predominant features of the PdAl/sub 2/Cl/sub 8/, CuAl/sub 2/Cl/sub 8/, and PdAl/sub 2/Br/sub 6/ spectra were three high-intensity, polarized bands which were attributed to the vibrational modes of the complex coupled to the electronic state of the central atom. The spectra of CuAlCl/sub 5/(g), CuInCl/sub 5/(g) and Cu/sub 2/Cl/sub 4/(g) species showed resonance enhancement of selective fundamentals which were attributed to vibrational modes of trigonally coordinated Cu(II). Resonance Raman spectra of U/sub 2/Cl/sub 10/(g) and UCl/sub 5/.AlCl/sub 3/(g) were characterized by the presence of a strong band attributed to the U-Cl/sub t/ stretching frequency. Raman band intensity measurements were carried out for the iron(III) chloride vapors and for the vapor complexes of CuAl/sub 2/Cl/sub 8/, CuInCl/sub 5/ and UCl/sub 5/.AlCl/sub 3/ using different laser powers and frequencies. The measurements suggested increasing spectroscopic temperatures and decomposition of the vapor complexes. The data are discussed in terms of the distribution of vibrational modes and the structure of the vapor species. 22 figs.
