The preparations and infrared spectra (400–130 cm.–1) are reported for the compounds M(tu)2(CH3CO2)2(tu = thiourea; M = Co, Zn, or Cd), M(tu)3XO4(M = Co or Zn, X = S or Se; M = Cd, X = S), Ni(tu)4XO4,MeOH (X = S or Se), M(tu)3S2O3(M = Co, Zn, or Cd), M(tu)3S2O3, H2O (M = Co or Zn), M(tu)4(ClO4)2(M = Co, Zn, or Cd) and M(tu)4(NO3)2(M = Co, Zn, or Cd). Electronic spectra and magnetic measurements are reported for the cobalt and nickel compounds. The structures of the complexes are discussed in the light of these results. All appear to have essentially tetrahedral co-ordination of the metal ion, except for the nickel complexes which are planar, and one of the three crystalline forms of Co(tu)4(NO3)2, in which severe distortion of the tetrahedron is indicated.