半胱胺-Zn(Ⅱ)络合反应稳定性及热力学特征研究  

Determination of Stability Constants and Thermodynamics of Cysteamine-Zn(Ⅱ)

作　　者：舒绪刚[1] 吴春丽[1] 周新华[1] 李翠金[1] 邱桂雄 

机构地区：[1]仲恺农业工程学院化学化工学院,广东广州510225 [2]广州天科生物科技有限公司,广东广州510627

出　　处：《分析科学学报》2016年第6期857-860,共4页Journal of Analytical Science

基　　金：广东省工程技术研究中心认定专项(No.2013B070704081);广东省科技计划(No.2014A020208131;2013B091500095);广州市科技计划(No.HD14CXY008;201508020048)

摘　　要：采用pH电位滴定法,于温度25℃条件下,获取半胱胺盐酸盐的各级加质子常数（lgK1H=10.92,lgK2H=8.25）、离解常数（Ka1=5.62E-09,Ka2=1.20E-11）及其与Zn（Ⅱ）形成配合物的稳定常数（lgk5=36.74）、热力学函数（△rHm=-157.14kJ/mol,△rSm=176.74J/（mol·K）,△rGm=-209.60kJ/mol）,并计算各pH条件下半胱胺盐酸盐与Zn（Ⅱ）配合的条件稳定常数。计算得Zn（Ⅱ）与半胱胺盐酸盐配位反应的热力学函数△rGm〈0、△rHm〈0、△rSm〉0,证明反应过程为自发放热。半胱胺盐酸盐与Zn（Ⅱ）形成配合物的稳定常数和条件稳定常数均很大,表明形成的半胱胺锌很稳定。Under the temperature of 25℃, pH potentiometric method was used to obtain protonation constant （lgK1H=10.92,lgK2H=8.25） and the dissociation constant （Ka1=5.62E-09,Ka2=1.20E-11） of cysteamine hydrochloriden,and the stability constants（lgk5 =36.74） and thermodynamic functions（△rHm=-157.14kJ/mol,△rSm=176.74J/（mol·K）,△rGm=-209.60kJ/mol） of the complex of cysteamine hydrochloride with Zn（Ⅱ） ions. The conditional stability constants at different pH were also calculated. Zn（Ⅱ） ions and cysteamine hydrochloride is revealed as a spontaneous exothermic reaction process,according to the result of △rGm〈0、△rHm〈0、△rSm〉0. The stability constants and conditional stability constants of complex were large, showing that the complex of cysteamine hydrochloride with Zn（Ⅱ） ions was very stable.

关 键 词：稳定常数 热力学函数 条件稳定常数 

分 类 号：O641.4[理学—物理化学]