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Mossbauer parameters are reported for a range of tin(IV) complexes, containing the potentially chelating ligands 8-hydroxyquinoline (oxH) and salicylaldehyde (salH). There are three main types of complex: (i) SnY2 ox2 and SnY2 sal2(Y = halogen, alkyl, or aryl); (ii) SnCl4–noxn(n= 0–4); and (iii) SnX4,2oxH and SnX4,2salH (X = halogen). From the quadrupole splitting data it is suggested that the carbon atoms in the complexes SnY2ox2(Y = alkyl or aryl) and the oxygen atoms in the complexes SnX4,2oxH occupy cis-positions. On the other hand trans-configurations are assigned to SnX4,2salH. Polymeric structures are suggested for SnCl4,oxH, SnCl3ox, and SnClox3.

Mossbauer and variable-temperature magnetic studies of the complexes FeX(ox)2 and FeX2(ox)(X = Cl or Br; oxH = quinolin-8-ol) suggest that they exist as magnetically isolated dimeric units in the solid state.

Mossbauer parameters are reported for the adducts SnX4,L (L = NMe3, X = Cl or Br; L = PPh3 or Ph2PCH2PPh2, X = Cl) and SnX4,2L (L = NMe3, X = Cl, Br, or I; L = NEt3; X = F; L = Py, PBun3, AsPh3, or AsEt3, X = Cl or Br; L = MeCN, PhCN, PPh3, PPh2Me, PPhEt2, or PEt3, X = Cl). Variations in chemical shifts for the adducts are discussed in terms of s character of the bonds to tin. Of the nitrogen donors, only the nitriles give rise to resolved quadrupole splitting. Triphenyl-phosphine and -arsine adducts give single-line spectra but quadrupole splitting is induced by replacing phenyl groups by alkyl groups. The five-co-ordinate adducts SnCl4,NMe3 and SnBr4,NMe3 give narrow-line spectra which exhibit no quadrupole splitting. I.r. and Raman data in the range 400–100 cm.–1 are reported for the 1 : 2 phosphine and arsine adducts. Attempts to prepare adducts of tin(IV) chloride and bromide with triphenylstibine resulted in reduction of the metal to tin(II).

The detailed infrared, Raman, and electronic spectra of the polymeric chromium(III) alkoxides have been measured. In conjunction with studies of magnetic susceptibilities and X-ray powder photographs, it is concluded that the methoxide and ethoxide possess layer lattices with the chromium atoms in an octahedral environment. Application of a Urey–Bradley force field to CrIII(OMe)3 gives excellent agreement with observed infrared and Raman frequencies.