主体化合物固定相与客体物质相互作用热力学的气相色谱法研究  

Study on the Thermodynamic Interaction between Host Compounds and Guest Substances by Gas Chromatographic Method

作　　者：孙得志[1] 郑小明[2] 陆维敏[2] 陈键[2] 

机构地区：[1]聊城师范学院化学系,山东聊城252059 [2]浙江大学西溪校区催化研究所,浙江杭州310028

出　　处：《分析测试学报》2002年第1期37-40,共4页Journal of Instrumental Analysis

摘　　要：应用气相色谱法测定了一些有机化学物质在 β_环糊精 (β_CD)固体表面上的吸附和在二苯并十八冠醚六 (DB18C6)及聚乙二醇 (PEG)液膜中的溶解热力学函数变量 ;实验结果表明 :气相中的有机组分在 β_CD表面上的吸附或在DB18C6液膜中的溶解过程之焓、熵互补现象不仅仅是已见诸报道了的TΔS°和ΔH°间的经验近似线性关系 ,当刚性的主体 (β_CD或DB18C6)分子和众多客体 (吸附质或溶质 )分子相互作用时 ,软、硬骨架的客体物质大致分属于两条TΔS°-ΔH°直线。Standard enthalpy ΔH° and entropy ΔS° changes of more than twenty organic compounds in adsorption/dissolution processes have been determined by using gas chromatographic technique. Pure solid β _ cyclodextrin (β _ CD) and supported films of dibenzo _ 18 _ crown _ 6(DB18C6) and polyethylene glycol 6000(PEG 6000) have been used as stationary phases in adsorption and dissolution processes, respectively. Experimental results indicate that enthalpy-entropy compensation exists in all the systems studied. An interesting fact has been found that the empirical straight lines of TΔS° versus ΔH° split into two groups. One group includes rigid guest molecules with β _ CD or DB18C6, whereas the other group contains all flexible guest molecules. Since the flexible guest molecules can change their configurations during their interaction with the rigid host molecules, these guest substances loose more entropy than the rigid guest molecules.

关 键 词：气相色谱 Β-环糊精 二苯并十八冠醚六 聚乙二醇 焓 熵 主体化合物 固定相 客体物质 相互作用 热力学 

分 类 号：O647.71[理学—物理化学] O642.1[理学—化学]