| Abstract: | Abstract Adducts of theobromine (tbH) with 3d metal perchlorates (Mn+ = Cr3-. Mn2+, Fe2+, Fe3+, Co2+, Ni2+, Cu2+, Zn2- I here prepared by refluxing mixtures of the Iigand and a metal salt in ethyl acetate-triethyl orthoformate. The new complexes invariably involve 2: 1 molar ratios of tbH to metal ion and are apparently monomeric with terminal tbH ligands binding riaa ring nitrogen (N9 or Nl). The Mn2+, Cu2+ and Zn2- complexes are distorted tetrahedral, involving tuo tbH and two unidentate perchlorato ligands in the first coordination sphere of the metal ion. The remaining metal(II) complexes (Fe, Co, Ni) were obtained as monohydrates. These compounds are pentacoordinated of the M(tbH)2(OClO3)2(OH2)] type, containing one aqua ligand in addition to the tbH and perchlorato ligands. The Cr3+ and Fe3+ complexes are low-symmetry hexacoordinated, with two tbH ligands. two unidentate and one bidentate chelating perchlorate Iigands. |
