Synthesis and characterization of water-soluble zinc, cobalt(II) and copper(II) complexes with a neutral tripodal N,N,N-ligand: Crystal structures of [(kappa N-3-4-TIPOiPr)Co(H2O)((KO)-O-2-NO3)]NO3 and [(kappa(3)-N-4-TIPOiPr)Cu(H2O)(kappa O-SO4)], 4-

摘要

The development of ligands bearing substituents to model a hydrophobic enzyme cavity and concurrently showing sufficient solubility in aqueous media seems somehow paradox. The zinc and cobalt(II) nitrato (4, 5) and copper(II) sulfato (6) complexes of the new tris(2-isopropylimidazol-4(5)-yl)phosphane oxide ligand (4-TIPO"i(Pr), 2a) show exactly these properties; in addition, the structure of the Co-II complex 5(.)MeOH(.)Et(2)O shows striking similarity to the active site of Co-II-substituted carbonic anhydrase. 2a and its metal complexes are stable towards hydrolysis which is in contrast to the known sensitivity of (imidazol-2-yl)phosphane oxides.