葫芦脲[7]与核黄素包结物的可能结构和光谱性质.pdf

物理化学学报( Wuli Huarue XI
Acta Phys.-Chim.Sin,2010,26(5):1417-1422
1417
Article
www.whxb.pku.edu.cn
葫芦脲?与核黄素包结物的可能结构和光谱性质
王素凡”周运友叶世勇周涛黄玉成
(安徽师范大学化学与材料科学学院,安徽芜湖241000
摘要:利用密度泛函理论对葫庐脉[和核黄素包结物的可能结构进行了理论计算.从5种可能结构分析主客
体在包结物中的作用得出:核黄素作为客体分子与主体葫芦服[分子通过不同官能团作用可形成稳定性不同
的包结物,其中以核糖醇的羟基插入到葫芦脉『7分子的腔体与其端羰基氧原子形成较多的氢键最稳定.在理论
上证明了此包结反应为一放热反应的实验事实,并进一步说明了包结物分子的相对稳定性受主客体分子的几何
畸变能和主客体之间作用能的影响,说明了成键能和稳定性之间的区别.在此基础上利用时间相关的密度泛函
理论进行了不同构型包结物的激发态计算并对光谱性质进行了理论预测.比较了包结物中核黄素分子的跃迁轨
道的组成变化,分析得出:葫芦脲的包结作用改变了核黄素分子的电子饫迁性质,使其吸收光谱发生红移.并
预测出其荧光猝灭的微观机理,此理论计算结果很好地解释了相应的实验现象
关键词:主客体复合物;包结物;葫芦脉[;核黄素;光谱性质
中图分类号:0641
Probable Configurations and Spectroscopic Properties of the Inclusion
Compound of Cucurbit[7uril and Riboflavin
WANG Su-fan ZHOU Yun-you YE Shi-yong ZHOU Tao HUANG Yu-
(College of Chemistry and Materials Science, Anhui Nornal University, Wuhu 241000, Anhui Province, P. R. China)
Abstract Possible configurations and optical properties of a cucurbit 7juril(B7)and riboflavin(VB2 )inclusion
compound were investigated by density functional theory (DF ).A comparison was made among the different structures
by an analysis of the interaction between the host and guest molecules. The results indicate that riboflavin sits on top of
the cucurbit(7 Juril molecule with a couple of hydroxyls inserting into the cavity to form H-bonds. We verify theoreticall
that the inclusion reaction is an exothermal reaction, which supports the findings from the experiment very well. The
sequence of stability for the possible inclusion complexes is strong evidence that the interaction between the guest and
host molecules and the distortion of the guest and host molecules both contribute to the stability. The bonding energy
and stability should be distinguished conceptually. The time-dependent DFT method was used in the excited state
calculations to explore the photochemical properties of the inclusion compounds. The component difference for the
excited orbitals in the different inclusion complex configurations was compared theoretically. The results show that
cucurbituril causes a red-shift absorption and fluorescence quenching for riboflavin after host-guest inclusion, which
strongly support the experimental data
Key Words: Host-guest complex; Inclusion compound; Cucurbit 7luril: Riboflavin; Spectroscopic property
Received: November 27, 2009; Revised: January 31, 2010: Published on Web: April 3, 2010
orrespondingauthor.Email:swang@mailahnu.edu.cn;Tel:+86-553-3878536
The roject was supported by the National Natural Science Foundation of China(07500) cientific Research Foundation for the Returned
Overseas Chinese Scholars, Ministy of Education China(2008-9), and Spcial Pje(zx200812 )and Doctors Project Grant of Anhui Normal
University, China
国家自然科学茱金(20875002)、教育部学回国人员科研启动基金(2008-98の)、安徽师范大学专项基金(xzx200812)和博士科研启动基金资助
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C Editorial office of Acta Physico-chimica Sinica