黄　远，王书改，李雯雯，韩秋霞*

( 1．河南大学化学与化工学院，河南开封475004; 2．开封市环境监测站，河南开封475001)



多酸基金属-有机框架的构筑及其催化性能

黄远1，2，王书改1，李雯雯1，韩秋霞1*

( 1．河南大学化学与化工学院，河南开封475004; 2．开封市环境监测站，河南开封475001)

摘要:在水热条件下合成了两个基于Keggin型磷钨酸盐的金属-有机框架化合物( MOFs) ［Er2H(μ-O)2( dpdo)4( H2O)2］［PW12O40］·3H2O ( 1)和［Tm2H(μ-O)2( dpdo)4( H2O)2］［PW12O40］·3H2O( 2) ( dpdo= 4，4'-bis( pyridine-N-oxide)，并通过元素分析、红外光谱( IR)、紫外光谱( UV)及单晶X射线衍射( XRD)的方法对其进行了结构表征．此外，通过紫外-可见分光光度法，在EPPS缓冲溶液中，考察了两种化合物在非均相体系中催化DNA模型磷酸二酯双(对硝基苯酚)磷酸二酯( BNPP)的水解进程．催化结果表明，在50℃，pH= 4的条件下，两种催化剂对BNNP催化的一级水解裂解速率为10－7～10－6s－1，最终产物为无机磷酸盐和对硝基苯酚．此外，该催化体系具有很好的重现性，并且催化剂可循环使用．

关键词:多金属氧酸盐;磷钨酸盐;金属-有机框架;水解裂解;非均相催化

Structures and catalytic performances of two polyoxometalate-based metal-organic frameworks

HUANG Yuan1，2，WANG Shugai1，LI Wenwen1，HAN Qiuxia1*

( 1．School of Chemistry and Chemical Engineering，Henan University，Kaifeng 475004，China; 2．Kaifeng City Environmental Monitoring Station，Kaifeng 475001，China)

Abstract:Two phosphotungstate incorporated metal-organic frameworks ( 1) ［Er2H(μ-O)2( dpdo)4( H2O)2］［PW12O40］·3H2O and ( 2) ［Tm2H(μ-O)2( dpdo)4( H2O)2］［PW12O40］·3H2O ( dpdo= 4，4'-Bipyridine-N，N'-dioxide) have been synthesized through a one-step hydrothermal reaction and characterized by elemental analyses，IR spectra，and single-crystal X-ray diffraction．Kinetic experiments for the hydrolytic cleavage of DNA-model phosphodiester BNPP ( bis( p-nitropheny) phosphate) were followed spectrophotometrically for the absorbance increase at 400 nm in EPPS ( 4-( 2-hydroxyethyl) piperazine-1-propane sulfonic acid) buffer solution due to the formation of p-nitrophenoxide with 1 and 2 under conditions of pH=4．0 and 50oC．UV spectroscopy indicates that the cleavage of the phosphodiester bond proceeds with the pseudo-first-order rate constant in the range of 10－7－10－6s－1，giving an inorganic phosphate and p-nitrophenol as the final products of hydrolysis．The results demonstrate that 1 and 2 have good catalytic activity and reusability for hydrolytic cleavage of BNPP．Keywords: polyoxometalate; phosphotungstate; metal-organic frameworks; hydrolytic cleavage; heterogeneous catalysis Two Ni( II) coordination polymers with the formulas of Ni2( 2，5-pdc)2( L1)2( H2O)2·6H2O ( 1)，Ni( 2，5-pdc) ( L2) ( H2O)·H2O ( 2) ［2，5-pdc = pyridine-2，5-dicarboxylic acid，L1= 1，1'-( 1，4-butanediyl) bis( imidazole)，L2= 1，1'-( 1，6-hexanediyl) bis( imidazole) ］have been prepared by the hydrothermal technique employing pyridine-2，5-dicarboxylic acid and two flexible bis-imidazole ligands with different spacer lengths．The three-dimensional ( 3D) framework of 1 is defined as a 4-connected CdSO4type topology with the Schläfli symbol of ( 65·8)．Complex 2 possesses one-dimensional ( 1D) circle-connecting-circle chain structure derived from 1D ［Ni( L2) ］nhelical chains and 1D ［Ni( 2，5-pdc) ］nchains．

金属-有机框架化合物( MOFs)是由金属离子和有机配体通过配位键组装而成的具有周期性网络结构的类分子筛材料［1］．由于具有稳定的晶态多孔结构、较大的比表面积、规则可调的孔径及可修饰的孔道表面等优点，该材料被广泛应用于催化、分离、分子磁性、药物传递等领域［2］．相比于结构组成相对单一的无机分子筛材料，MOFs除了可以通过金属离子或金属簇中心和有机连接配体的变化来调控空腔和孔洞尺寸大小实现择形催化外，还可以直接引入多种催化功能……