Synthesis, Crystal Structures And Urease Inhibitory Activities Of Transition Metal Complexes With Schiff Bases

The complexes, synthesized with transition metal ions 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. Based on a great deal of the relevant literatures, we have synthesized 15 new transition metal complexes of 9 Schiff base ligands and studied their crystal structures and bioactivities. The following are the main work we have carried out:1. The ligands HL1 to HL7 of 2-ethoxyethyl-6-[(2-dimethylaminopropylimino) methyl]phenol (HL1), 4-bromo-6-[(2-isopropylaminoethylimino)methyl]phenol (HL2), 2-ethoxyethyl-6-[(2–ethylaminoethylimino)methyl]phenol (HL3), 2-{[2-(5-methylpyridine-2- imino)]methyl}phenol (HL4), 2-ethoxyethyl-6-[(2-cyclohexaneaminopropylimino)methyl]- phenol (HL5), 2-[2-(4-methylpyridine-2-imino)methyl]phenol (HL6) and 2-ethoxyethyl- 6-[(2-methylaminopropylimino)methyl]phenol (HL7) have been designed and synthesized. Ten complexes have been synthesized through the reaction of the ligands and the Zn2+ ions. The single-crystal complexes of ten complexes have been obtained via the advanced culture and their structures have been analysed by the X-ray test. [Zn3(L1)2(μ1,1-N3)2Cl2] 1, [Zn3(L1)2(μ1,1-N3)2Br2] 2 and [Zn3(L1)2(μ1,1-N3)2I2] 3 are trinuclear compexes; [Zn2(L2)2(μ1,1-N3)Br2]·H2O 4, [Zn2(L3)2(μ1,1-N3)I]·HI 5 and [Zn2(L4)2I2] 6 are dinuclear complexes; [Zn(L5)(N3)I] 7, [Zn(L6)(C6H8N2)I] 8, [Zn(L7)I2(MeOH)] 9 and [Zn(L7)2(NCS)]·NCS 10 are mononuclear complexes.2. Another two Schiff base ligands of 2-ethoxyethyl-6-(pyridine-2-methylimino)phenol (HL8) and 2-ethoxyethyl-6-[(2-propylaminoethylimino)methyl] phenol (HL9) have been designed and synthesized. Five complexes, [Cd2(L8)2(NCS)2] 11, [Cd2(L1)2(NCS)2] 12, [Co(L7)2]·ClO4 13, [Mn(L9)2(NCS)(H2O)] 14 and [Cu(L9)(NCS)] 15 have been synthesized through the reaction of the ligands and four metal ions Cd2+, Co2+, Mn2+ and Cu2+, respectively. The single-crystals of seven complexes have been obtained via the advanced culture and their structures have been analysed by the X-ray test. Both complexes of Cd2+ ions are dinuclear complexes, while the others are mononuclear complexes.3. The urease inhibitory activities of seven complexes have been tested. The complexes containing Zn(II), Co(II), Mn(II), and Cu(II) atoms exhibit urease inhibitory activity. The relationship between the structures of the complexes and the biological properties has been investigated. This may help us explore novel urease inhibitors.