Synthesis and characterization of a series of diphenyldipyrazolylmethane complexes with zinc(II)

The zinc(II) coordination chemistry of a series of diphenyldipyrazolylmethane ligands was explored using H-1 NMR and single crystal X-ray diffraction. Unsubstituted diphenyldipyrazolylmethane (dpdpm), diphenylbis(3-methylpyrazolyl) methane (dpdp'm), and diphenylbis(3,5-dimethylpyrazolyl) methane (dpdp '' m) were reacted with Zn(NO3)(2) to afford Zn(dpdpm)(NO3) 2, Zn(dpdp'm)(NO3)(2) and Zn(Pz '')(2)(NO3)(2) where Pz '' = 3,5-dimethylpyrazole, respectively. All attempts to isolate Zn(dpdp '' m)(NO3)(2) with the intact dpdp '' m ligand were unsuccessful due to decomposition of the ligand. These bidentate ligands support the formation of 1:1 ligand to metal complexes and structurally model the two histidine coordination mode common in zinc proteins. Published by Elsevier B. V.