香豆素-3-羧酸铒（Ⅲ）一维配位聚合物Er（CCA）_3（H_2O）_2_n·2nH_2O的溶剂热法合成、晶体结构及与牛血清白蛋白（BSA）的相互作用

摘要

利用溶剂热法合成了一维配位聚合物[Er（CCA）3（H2O）2]n·2nH2O（HCCA=香豆素-3-羧酸）,通过元素分析和IR对配合物进行了表征,用X-射线单晶衍射技术测定了其晶体结构.标题配合物晶体属于单斜晶系,P21/c空间群：a=0.6310（1）nm,b=1.4165（2）nm,c=3.1731（3）nm;β=91.861（2）°,V=2.8346（7）nm3,Dc=1.890 g·cm-3,Z=4,F（000）=1596,残差因子R1=0.0525,wR2=0.0930[I〉2σ（I）],S=1.290.配合物的金属中心与来自配体（CCA）和配位水分子的8个氧原子进行配位,形成了一个畸变的十二面体,两个相邻的铒（Ⅲ）离子通过一个羧基桥连成为一维聚合物.用荧光光谱法研究了不同温度下配合物与牛血清白蛋白（BSA）的相互作用,结果表明,配合物对BSA的荧光猝灭属于静态猝灭,计算了不同温度下配合物与BSA间的结合常数（Ka）,结合位点（n）及相关热力学参数（ΔH〉0,ΔS〉0）,二者主要靠疏水作用力结合.依据Fster’s非辐射能量转移理论,求得给体（BSA）与受体（配合物）间的距离r=2.85 nm,说明配合物与BSA之间发生了非辐射能量转移.%A coordination polymer [Er（CCA）3（H2O）2]no2nH2O（HCCA=coumarin-3-carboxylic acid） has been prepared by solvent-thermal method and characterized by elemental analysis and IR spectra and single crystal X-ray diffraction.The crystal of erbium（Ⅲ） complex belongs to monoclinic system with space group,P21/c,a=0.6310（1） nm,b=1.4165（2） nm,c=3.1731（3） nm;β=91.861（2）°,V=2.8346（7） nm3,Dc=1.890 gocm-3,Z=4,F（000）=1596,residual factors R1=0.0525,wR2=0.0930 [I2σ（I）],S=1.290.The Er（Ⅲ） atom is eight-coordinated by eight O atoms from three ligands（CCA） and two coordinated water molecules,and the coordination polyhedron around the Er（Ⅲ） atom can be best described as a distorted dodecahedron geometry.Two adjacent Er（Ⅲ） atoms were bridged into a one-dimensional polymeric chain by the carbox-ylic group in a ligand（CCA）.The interaction between complex and bovine serum albumin（BSA） was in-vestigated by fluorescence spectroscopy at different temperature.The results indicated that the complex quenches the fluorescence of BSA through a static quenching procedure.The binding constants（Ka） and the number of binding sites（n） between the complex and BSA were calculated at different temperature.The corresponding thermodynamic parameters enthalpy changes（ΔH0） and entropy changes（ΔS0） were also obtained according to the van＇t Hoff equation.The primary binding pattern between complex and BSA was interpreted as hydrophobic interaction.The binding average distance r between the donor（BSA） and acceptor（complex） was obtained to be 2.85 nm based on the Fster＇s theory,which indicates the non-radiation energy transfer can occur from BSA to complex with high probability.