镨配合物的热化学及其对酵母菌作用的热动力学研究

用六水合氯化镨、硫代脯氨酸(C4H7NO2S)和水杨酸(C7H6O3)合成了三元固体配合物Pr(C7H5O3)2(C4H6NO2S)]-2H2O.根据盖斯定律设计一个热化学循环,用溶解-反应量热法研究得到合成反应的标准摩尔焓变为(133.70±1.02)kJ/mol,配合物298.15K时的标准摩尔生成焓为-(2909.3±3.2)kJ/mol.用TAMair微量热仪测定其在28.00℃时对粟酒裂殖酵母作用的产热曲线,进而算出在配合物作用下,酵母菌生长代谢的最大发热功率Pmax、速率常数κ、传代时间tG、抑制率I和半抑制浓度cI,50等热动力学参数.结果表明:稀土水杨酸硫代脯氨酸配合物在低浓度下对酵母菌有刺激作用,高浓度下为抑制作用,即稀土配合物对微生物的生长具有双向生物效应,也称为Hormesis效应.

Thermochemical and thermokinetic studies on complex of praseodymium

The ternary solid complex of Praseodymium with salicylic acid and Thioproline,Pr（C7H5O3）2-（C4H7NO2S）]-2H2O,was synthesized.The enthalpy change of the reaction was determined to be Δ r Hmθ=（133.70± 1.02） kJ/mol,the standard molar enthalpy of formation of Pr（C7H5O3）2-（C4H6NO2S）]-2H2O（s） was estimated to be θ Δ f HmPr（C7H5O3）2（C4H6NO2S）-2H2O（s）,298.15 K]=-（2909.3 ± 3.2） kJ/mol.The thermokinetic properties of the action on growth metabolism of Schizosaccharomyces pombe were studied by means of a TAM air isothermal calorimeter at 28.00 ℃.The maximum heat output power Pmax,growth rate constant κ,generation times tG,inhibitive rate I（%） and half inhibition concentration cI,50 were obtained,respectively.Experimental results show that Pr（C7H5O3）2（C4H6NO2S）]-2H2O possess the bi-directional biological effect and Hormesis effect,which stimulate the growth of Saccharomycete at lower concentration,but inhibit the growth at higher concentration.