【作者】 龚勇华；

【导师】 汤杰；

【作者基本信息】 华东师范大学 ， 物理化学， 2007， 博士

【摘要】 本论文分为两部分:第一部分为“1,2,4,5-四嗪的合成,电化学以及荧光性质研究”;第二部分为“含二茂铁的吡啶盐类化合物的合成与电化学性质研究”。第一部分中,首先在第一章简要介绍了1,2,4,5-四嗪化学,包括其一般合成方法,反应性以及在不同领域的应用。第二章介绍了超分子化学的一般概念,包括非共价键相互作用,荧光分子探针以及电化学分子探针等。鉴于阴离子在生物体系和环境体系中的重要作用,关于阴离子探针分子的研究进展也做了简要介绍。富电子化合物的检测在环境监测和污染控制方面具有重要意义,但对于该类探针分子的研究却相对很少。作为缺电子的杂环,四嗪经由阴离子-π相互作用络合阴离子的能力已经由理论计算予以证实。Audebert小组的工作又表明,部分四嗪化合物具有良好的电化学可逆性以及荧光特性,并且其荧光信号可随富电子化合物的加入而发生响应。在此基础上我们设计了一系列探针分子,包括镊子型、三足型、环番以及杯状构造的分子,其中的四嗪既作为络合单元同时又作为信号单元。其中,一个三足型四嗪(86),两个含四嗪的环番(90,93)和两个杯状构造的四嗪(94,95)被成功合成。荧光性质研究表明,化合物86,90,94和95的荧光能够有效地被加入的富电子化合物如三苯胺,三-4-溴苯胺,吡咯,四硫富瓦烯以及1,3,5-三甲氧基苯等淬灭。电化学研究也表明这些探针分子与富电子化合物之间存在相互作用。对某些荧光淬灭实验中的淬灭机理也进行了研究;对于部分分子的轨道能级进行了计算,用于解释荧光性质与分子结构的关系。第二部分介绍了一个双臂的二茂铁吡啶盐(45j)和两个三臂的二茂铁吡啶盐(46h,46j)的合成。目标化合物经过1,2,6-三甲基吡啶盐或1,2,4,6-四甲基吡啶盐与相应的芳香醛缩合得到;同时建立了一条新的合成路线合成了两个重要的中间体芳香醛,反式-二茂铁乙烯基噻吩甲醛(47)和反式-二茂铁乙烯基联噻吩甲醛(48)。初步的电化学研究表明联噻吩共轭桥对于分子的电化学行为具有极大影响。更多还原

【Abstract】 This thesis consists of two parts. The first one deals with the synthesis and electrochemical and fluorescence studies of new 1,2,4,5-tetrazine derivatives as molecular sensors for anions and electron-rich compounds, and the second one with the synthesis and preliminary electrochemical studies of ferrocene-containing pyridinium salts.In part I, a short overview of 1,2,4,5-tetrazine chemistry (s-tetrazine) is presented. s-Tetrazines have already found applications in many fields, but their ability to bind anions or electron-rich compounds through anion-π interaction or π-π stacking has not been noticed until very recently. In this context, a series of novel molecular sensors containing tetrazine moieties as both binding units and sensing units are designed, including tweezer-tetrazines, tripod-tetrazines, cyclophane-tetrazines, and calycular tetrazines. Among them, a tripod-tetrazine (86), two cyclophane-tetrazines (90, 93) and two calycular tetrazines (94, 95) have been successfully synthesized based on S_nAr reactions of 3,6-dichlorotetrazine (23). Fluorescence studies show that the fluorescence of 86, 90, 94 and 95 can be efficiently quenched by electron-rich compounds such as triphenylamine (TPA), tris(4-bromophenyl)amine, pyrrole, tetrathiafulvalene (TTF) and 1,3,5-trimethoxybenzene. Electrochemical studies also indicate the interactions between the tetrazine sensors and these electron-rich compounds. The fluorescence quenching mechanisms are investigated in some cases, and calculations on molecular obitals are carried out to investigate the relationship between molecular structures and fluorescence properties.In part II, the synthesis of a dibranched ferrocene-containing pyridinium salt (45j) and two tri-branched ones (46h, 46j) through the condensations of 1,2,6-trimethyl pyridinium or 1,2,4,6-tetramethyl pyridinium with aromatic aldehydes will be presented. A new synthetic route is also developed for the two important intermediates, trans-5-(2-ferrocenyl-vinyl)-2-carbaldehyde-thiophene (47), and ferrocenylethenyl-bithiopheneyl aldehyde (48). Preliminary electrochemical studies show that bithiophene units influence greatly the redox behaviors of the molecules.更多还原