摘要
为了模拟客体分子与气相色谱固定相间的弱相互作用,研究了不同聚合度的硅氧烷寡聚物的性质,并以聚合度为3的硅氧烷寡聚物为主体,以多氯苯酚乙酸酯、三溴苯酚乙酸酯及三甲基苯酚乙酸酯为客体,主体与客体以1∶1的物质的量之比形成6个复合物。采用密度泛函理论(DFT)计算了若干主体和复合物的性质。结果表明,复合物的结合能越大,主体与客体的相互作用越强,客体在气相色谱中的保留时间越长。复合物中Si—O链末端甲基上C原子的化学位移与主体中同一个C原子化学位移相比向高场移动,复合物中的苯环与主体中同一苯环相比芳香性增强,主要是由于Si—O链上O原子的存在导致附近苯环上的电子云密度增大。量化计算的复合物结合能和能隙与实验测定的保留时间具有很强的相关性,表明量化参数可以有效运用于气相色谱中客体保留情况的描述和预测,同时也可对复合物的光谱性质进行理论描述。
In order to simulate the weak interaction between guest molecular and stationary phase in gas chromatography（GC）,the properties for oligomers of siloxanes with different polymerization degrees are studied.The oligomer of siloxane with polymerization degree 3 is used as host,chlorophenol acetates,tribromophenol acetate and trimethylphenol acetate are used as guests.Six complexes are designed in the 1∶1 molar radio by host to guests.The properties of several hosts and complexes are calculated using density functional theory.The higher binding energies of the complexes lead to longer experimental retention times of the guests.The chemical shifts by NMR of the C atoms in the methyl groups at the end of the Si—O chains of the complexes locate at upfield compared with the same C atoms from the hosts.The aromaticities of the benzene rings in the complexes in comparison to the same benzene rings from the hosts increase,owning to the increase of electron clouds density on the benzene rings adjacent to the O atom on the Si—O chains.The calculated results on binding energies and energy gaps of the complexes are in strong relation to the experimental retention time of the guests,and thus this calculation model is reliable and reasonable for describing and predicting the sequence of retention time for the guests.Besides,it can also be used for the theoretical description of the spectroscopic properties for the complexes.
作者
张海琪
滕启文
吴师
ZHANG Hai-qi;TENG Qi-wen;WU Shi(Department of Chemistry,Zhej iang University,Hang zhou 310027,China;Key Laboratory of Applied Chemistry of Zhejiang Province,Hangzhou 310027,China)
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2018年第3期369-374,共6页
Journal of East China University of Science and Technology
