Synthesis, Biological Activities Of Schiff Bases And Functional Complexes With Transition Metals

The complexes, synthesized with transition metal and Schiff bases as reactants, are more and more becoming the focus of contemporary research. Owing to their various structures and peculiar properties, the use foreground of these complexes is also promising in many fields, such as catalysis, bioactivity and material. After going over and analyzing a great deal of the relevant literatures, we have synthesized more than 300 kinds of compounds and 15 new transition metal complexes including 12 complexes of Schiff bases and studied their crystal structures by x-ray and studied their bioactivities also.Eleven Schiff base ligands have been designed and synthesized. They are derived from the condensation of salicylaldehyde with naphthalidine, 2-cyano-4-chloroaniline, o-Toluidine, N-aminoethylmorpholine, benylamine, butylamine, cyclopentylamine and 3-carboxysalicylidene with N-aminoethylmorpholine, benylamine, 2-hydroxyaminoethylamine, ethylenediamine, respectively.We have obtained the crystal structures of HL1,HL2 and HL3; synthesized the copper(II) complexes with HL3, HL4, HL5, HL6 and H2L11; synthesized the cobalt(II) complexes with HL7, H2L8, HL9, HL10 and H2L11; also the nickel(II)complex with H2L11. Besides, we have designed and synthesized three silver(I) complexes with 5-bromoslicylic acid, 2-aminobenzoic acid, hexamethylenetereamine as raw materials. All the structures have been determined by via the X-ray test. The mononuclear complexes are Cu(L3) 2,Cu(L5) N3·2H2O,Co(L7) 3,Co(L9)3·NO3;The dinuclear complexes are Cu2 (L4) 2(C6H5COO)2,Cu2 (L4) 2(o-F-C6H5COO)2,Cu2 (L6) 2 (N3)2; and [Co3(L8)2(C5H5N)6·2(ClO4)]n and [Ag(5-bsa)]n are one-dimensional chain structure. The X-ray disclosed [Ag(2-aba)]n and [Ag(μ3-hmt)( C6H5COO)·H2O]n are all present as a two-dimension net-work configuration.Using eleven ligands (HL1~H2L11) and 15 complexes as enzyme inhibitors, we have tested their inhibitory bioactivities against Urease and Xanthine Oxidase(XO). Studied the relative between their structure and bioactivities and found that the kind of metal ions, coordinated ligands, the uncoordinated molecules and the weignt of molecular are have great influence to the inhibitory bioactivities against Urease and XO. We find that none of these organic ligands exhibited ability to inhibit Urease and XO. At the same time, merely Cu2+, Ni2+,Co2+,Ag+, the bioactivities is limited. While they coordinated with the organic ligands, the stability of the ion is greatly advanced and the bioactivities have great changes. Nearly all the copper(II) and nickel(II) complexes could inhibit the activities of Urease and XO. However, bioactivity of Urease could be inhibited by the complexes containing Co2+ and Ag+, which failed to inhibit the bioactivity of XO. Cu and Ag belong to the IB, analogous electronic shell configuration lead to the similar inhibit activities against Urease. The more the uncoordinated water molecules, more group can forming hydrogen bonds and the great degree of polymerlization, the more inhibit bioactivities against Urease.Structure determine the quality while quality influence the function. The structures of transition complexes have the inherent stability and diversity. The study of structure-activity relationship with Urease and XO can help us to find a ideal inhibitor, which have signality progress both in theory and realism.