the value of & at three temperatures is calculated to be 0.9,close to 1,suggesting that the reaction likely follows the firstorder kinetics. Based on the first-order kinetics,the reaction rate constants(Ka)at 298.15 K 303.15 K and 308.15 K are calculated as 2.2x10-4 s-1,2.4x10-4 s-1 and 5.4x10-4s-1,respectively.It is found that the rate constants increase monotonically as the temperature is raised.The temperature dependence of the rate constants can be evaluated according to the Eyring theory of activation.According to the theory,the activation energy for the binding reaction can be estimated to be 66.6 kj mol-1 from the linear relationship between In Ka and the reciprocal thermodynamic temperature(1/T)