Abstract
We synthesis two ligands in our experiment.The first ligand, tris(2-benzylaminoethyl)amine(Bz3tren), was obtained by adding benaldyhyde to a solution of tris(aminoethyl)amine(tren).Then NaBH4 was added to reduce the compound.The second ligand, 1,4,7,11-tetraazacyclotetradecane(isocyclam) was obtained by the method of Richman and Atkins.We synthesis isocyclam by the use of a protecting group.The dissociation kinetics in acid medium for the copper(Ⅱ) tripodal complex have been investigated by spectrophotometric method in 4.1’10-3M - 3.0’ 10-1M and pH2.3 - pH3.7. The possible mechanism for the cleavage of copper-nitrgen bond to the rate were proposed. And we determined thermodynamic parameters of DH1 and DS1 with Eyring equation from rate values of different temperature. Two different intermediates are required to explain two sets of thermodynamic parameters in higher acid concentration and lower acid concentration.The dissociation kinetics in strongly acid medium for the copper(Ⅱ) macrocyclic complex have been investigated by spectrophotometric method in 0.1-0.5.0M. This process was not found to occur by a single stage but to take place in consecutive-reversible steps. This kinetic scheme that can accommodate our observations is given in the following equation.Here B is an intermediate, and k1, k-1, and k2 first-order or pseudo-first-order rate constants. The possible mechanism for the cleavage of copper-nitrgen bond to the rate were proposed by the directly protonation, the solvention and the intramolecular hydrogen-bonding pathways.