| Phenolic compounds serve as raw materials or intermediates,and use in a variety of products for the chemical industries.Phenols show highly injurious to organism because these compounds are found very difficult to degradate and easy to cumulate in food chains.It is a major international task to remove phenols efffciently from waste water.The oxidation of phenols can be catalyzed by natural oxidase enzyme rapidly and efficiently.Natural oxidase enzyme can be simulated by model compounds synthesized with chemical method.A mechanism for the oxidation catalyzed by model compounds can be proposed.These studies are very important in theory and in application for treatment of waste water containing phenols.Copper(Ⅱ)complexes with Schiff base ligands ofβ-alanine with salicylaldehyde were synthesized.Three new complexes,such as[Cu(Sal-β-Ala)(3,5-DMPz)2].2H2O(1), [Cu(Sal-β-Ala)(3,5-DMPz)2 CH2](2)and[Cu(Sal-β-Ala)(2,2'-bipy)].2H2O(3)with 3, 5-Dimethyl prazole,1,1-Bis(3,5-dimethylprazol-l-yl)methane,and 2,2'-bipyridine were prepared.Copper(Ⅱ)complexes with reduced Schiff base ligands of glycine(or D, L-alanine,L-leuvine,L-valine)with salicylaldehyde(or benzaldehyde and anisaldehyde) were synthesized.Five new Copper(Ⅱ)complexes,such as[Cu(SalGly)(2,2'-bipy)2]. 3H2O(4),[Cu(Sal-D,L-Ala)(2,2'-bipy)].NO3.2H2O(5),[Cu(Sal-L-Leu)Him](6),[Cu(aen -L-Val)2(H2O)].2H2O(7)and[Cu(Ani-D,L-Ala)bipy].NO3(8)with 2,2'-bipyridine and imidazole were prepared.All complexes were characterized by X-ray diffraction,EA, IR,and TGA.The hydrogen-bonding systems do great influence on the coordination geometry and crystal packing.Complex 1 crystallized in space group P2(1)/c,Z=4,with a=19.619(4)(A),b =8.2103(15)(A),c=13.890(3)(A),α=90℃,β=91.493(2)°,Υ=90°;2 crystallized in space group P-1,Z=4,with a=8.1395(9)(A),b=14.3894(16)(A),c=19.271(2) (A),α=71.7600(10)°,β=79.4110(10)°,Υ=79.9660(10)°;3 crystallized in space group C2/c,Z=8,with a=15.1164(14)(A),b=13.1426(12)(A),c=19.6898(19) (A),α=90°,β=91.2040(10)°,Υ=90°;4 crystallized in space group Cc,Z=4,with a=5.2835(8)(A),b=22.539(3)(A),c=16.625(3)(A),α=90°,β=98.029(2)°,Υ= 90°;5 crystallized in space group P2(1)/c,Z=4,with a=10.7680(13)(A),b= 26.834(3)(A),c=7.7263(10)(A),α=90°,β=99.001(2)°,Υ=90°;6 crystallized in space group P2(1)2(1)2(1),Z=4,with a=7.1094(9)(A),b=12.0945(15)(A),c= 19.731(3)(A),α=90°,β=90°,γ=90°;7 crystallized in space group P2(1)2(1)2(1), Z=4,with a=9.0263(7)(A),b=13.9575(12)(A),c=21.9943(18)(A),α=90°,β=90°,γ=90°;8 crystallized in space group P2(1)/c,Z=4,with a=14.196(3)(A),b =13.753(3)(A),c=11.532(2)(A),α=90°,β=102.038(2)°,γ=90°.Copper(Ⅱ)complexes,such as[Cu2(Sal-L-Leu)2(H2O)].0.5H2O(9),[Cu2(Sal-L-Thr)2(H2O)]. H2O(10),[Cu2(Sal-L-Met)2(H2O)].H2O(11),[Cu2(Sal-L-Phe)2(H2O)2].H2O (12)and[Cu2(Sal-L-Tyr)2(H2O)].2H2O(13)possessing reduced Schiff base ligands of L-leuvine(or L-threonine,L-methionine,L-phenylalanine,L-tyrosine)with salicylaldehyde were synthesized.All complexes were characterized by EA,IR,and TGA.The compounds 5,9,10,11,12,13 have been evaluated as a model system for catechol oxidase enzyme,and it is found that all compounds show catalytic influence on the oxidation of the model substrate 3,5-di-tert-butylcatechol to 3,5-di-tert-butylo-quinnone under aerobic conditions.The influence of pH,substrate concentrations, catalyst concentrations and additive concentrations for catalytic oxidation had been studied.In order to determine the kinetic parameters,a kinetic treatment on the basis of the Michaelis-Menten model to be applied,a first-order dependence was observed at low concentrations of the substrate.The data obtained from Eadie-Hofstee plot.The kinetic parameters of Vm(△A.min-1),Km(mol.L-1)and kCat.(min-1)are as follows:5: 2.53×10-2,3.40×10-3,38;9:1.64×10-2,8.16×10-4,90;10:1.18×10-2,9.41×10-5, 153;11:2.46×10-2,5.98×10-4,170;12:1.33×10-2,4.01×10-3,14;13:1.74×10-2, 1.09×10-3,72.The catecholase activity follows the order:11＞10＞9＞13＞5＞12.It is argued that the difference in activity among complexes may be attributed to the difference in the coordination geometry of Cu(Ⅱ)and the side chain of amino acids in the reduced Schiff base ligand for 9,10,11,12,13.Oxygen atoms O(3)of the carboxylate group interact weakly with Cu(Ⅱ)from the adjacent unit,and form an one-dimensional chain in compound 5.The least distance of Cu...Cu is 5.476(A)in the chain, likely to be around 5.0(A).Although the structure consists of monomeric units with copper center,compound 5 shows the catecholase activity.In addition,a mechanism for the aerobic catechol oxidation catalyzed by the complexes needs to be considered.
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