以多羧酸为桥的锌配合物的合成和热分解动力学研究

Synthesis of zinc complex with polycarboxlate as bridging ligand and study on its thermal decomposition kinetics

在水-甲醇体系中,Zn(C2H3O2)2.2H2O与吡唑、邻苯二甲酸氢钾水热反应,形成以邻苯二甲酸根桥联的在xy平面一维无限的锯齿形链状锌的配位聚合物[Zn(μ2-C6H4(COO)2)(pz)2],用元素分析,红外光谱等进行了表征,并用X-ray测定了配合物的晶体结构.此外,还对配合物进行了非等温热分解动力学研究.研究表明:此配合物的热分解反应是分两步进行的.通过计算,该配合物热分解的第一步反应的可能机理为化学反应,第二步反应的可能机理为成核与生长,n=1/4,其动力学方程分别为:dα/dT=A/βe-E/RT(1-α)2和dα/dT=A/βe-E/RT1/4(1-α)[-Ln(1-α)]-3.热分解反应的表观活化能分别是177.95和303.8 kJ/mol;指前因子InA分别是41.87和53.74 s-1.

Using h ydrothermal synthesis method, reaction of Zn（ C2H3O2 ）2 （2H2O, pyrazole and phthalate in the system of EtOH/H2O, results in a Zn （Ⅱ） coordination polymer. Both carboxylate groups of the phthalate dianion bridged two Zn （Ⅱ） atoms forming the structure of 1-D chain at the plane of xy. The coordination polymer was characterized by elemental analysis, IR spectroscopy and the crystal structure was determined by X-ray diffraction. Besides, the kinetics of thermal decomposition of the complex was studied by thermal analysis technique. Thermal decomposition of the complex was separated into two steps. The possible reaction mechanism for the first step is suggested to be a second order chemical reaction, the second step is suggested to be nucleation and growth n = 1/4. The kinetic equations may be expressed as： dα/dT = A/β^- E/RT（ 1 - α）2 and dddT = A/13e- E/RT 1/4（ 1 - α）[ - Ln （ 1 - α） ] ^- 3 respectively. The apparent activation energy was 177.95 and 303.8 kJ/mol respectively and pre-exponential factors （InA） of the reaction were 41.87 and 53.74 respectively.