刚性柱双π墙金属有机框架:单晶到单晶结构转换,碘富集与缓释,协同导电性研究  

Rigid Pillars and Double Walls in a Porous Metal-Organic Framework:Single-Crystal to Single-Crystal,Controlled Uptake and Release of Iodine and Electrical Conductivity

作　　者：曾明华[1] 李丹丹[1] 殷政[1] 王强心[1] 张东材[1] 

机构地区：[1]广西师范大学化学化工学院,广西桂林541004

出　　处：《广西师范大学学报（自然科学版）》2012年第3期171-177,共7页Journal of Guangxi Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(20871034);广西自然科学基金资助项目(00832001Z;GKN0630006-5D);教育部"新世纪优秀人才支持计划"资助项目(NCET-07-217);广西新世纪十百千人才工程第二层次人选资助项目(2006201)

摘　　要：本文在溶剂热条件下利用刚性柱型金属手性配位链(Zn-lactate),辅助于三角架桥联配体(pybz)构筑了目前第一例高稳定性、双π墙的纳米孔道配位聚合物Zn3(pybz)2(lac)2·2.5DMF(1)。化合物1具有孔径为1.12nm×1.02nm的一维纳米通道,其孔洞率Vvoid为43.5%,Langmuir比表面积为918.5m2.g-1,热稳定性高达400°C。化合物1通过晶态转换的方式得到去客体化合物Zn3(pybz)2(lac)2(1′)。1′在碘的环己烷溶液中展现出对碘分子前所未有的超级富集与控释效果,单位碘负载量达到1g I2/g1′,同时载碘单晶在乙醇溶液中可实现碘的可控释放。由于客体I2分子与主体双壁π电子两者间交替的电荷转移,导致载碘单晶的导电性能比碘单质剧增440倍。上述研究,在国际上首次发现了绝缘性客体与绝缘性配位聚合物主体协同有序电荷转移进而导电性剧增的特殊现象。The first high stable micro-porous metal-organic framework with rigid pillars and double-walls,Zn3（pybz）2（lac）2·2.5DMF（1） was constructed from infinite pillars {[Zn3（DL-lac）2]2＋}n and 4-pyridyl benzoate （pybz） which is long,polar and ditopic at the opposite ends through the pyridine and the carboxylate under solvothermal reaction.1 crystallized in tetragonal P4—21c space group.There are 1D channels running along the c axis with window size of 1.12×1.02 nm2 in 1.A void volume of 43.5% was calculated by PLATON.A Langmuir surface area of 918.5 m2·g-1 further confirms the permanent porosity of complex 1′.The framework of 1 is highly stable up to 400 °C which is confirmed by TG and variable temperature powder X-ray diffraction measurement.Guest removed phase Zn3（pybz）2（lac）2（1′） can be obtained through single-crystal to single-crystal transformation.1′ shows outstanding iodine enrichment ability in cyclohexane solution of I2 and one gram of 1′ can absorb approximately 1 g of iodine to obtain {[Zn3（pybz）2（lac）2]·3I2}n（1′·3I2）.1′·3I2 shows controlled iodine releasing in ethanol solvent.The potential intermolecular interactions between I2 and π-electron walls induced n→σ＊ charge-transfer and resulted in cooperative electrical conductivity for of 1′■3I2,which is about 440 times higher than iodine.A special phenomena was found that increased electrical conductivity resulted from cooperative interaction between insulating guests and insulating coordination polymers for the first time.

关 键 词：金属有机框架 单晶到单晶结构转换 碘富集与缓释 协同导电性 

分 类 号：O641[理学—物理化学]