新型低聚噻吩衍生物的合成及其凝胶化性能研究

设计合成了一系列新型低聚噻吩衍生物N,N'-双十八烷基-5,5"-(2,2:5,2"-三噻吩)二酰胺N,N'-distearyl-5,5"-(2,2:5,2"-terthiophene) dicarboxamide (DNC₁₈₃T)]、N,N'-双烷烃基-5,5"-(3,3"-双辛烷基-2,2:5,2"-三噻吩)二酰胺N,N'-dialkyl-5,5"-(3,3"-dioctyl-2,2:5,2"-terthiophene)dicarbox-amide(DNC_nDOc3T,n=5,8,16,18)]及N,N'-双十八烷基-5,5-(3,3-双辛烷基-2,2:5,2":5",2-四噻吩)二酰胺N,N'-distearyl-5,5-(3,3-dioctyl-2,2:5,2":5",2-tetrathiophene)-dicarboxamide(DNC₁₈DOc4T)].研究结果表明,DNC₁₈₃T和DNC₅DOc3T同有机溶剂不形成凝胶.DNC_nDOc3T(n=8,16,18)和DNC₁₈DOc4T能同几种有机溶剂形成透明、半透明或不透明的凝胶.通过测定凝胶随温度变化的红外光谱(IR)、核磁共振氢谱(¹HNMR)、紫外光谱(UV),揭示出形成有机低分子凝胶的驱动力不仅有分子间氢键,而且π-π相互作用也是一个非常重要的因素.偏光光学显微镜、扫描电子显微镜(SEM)显示出有机低分子凝胶呈三维网络结构.另外,DNC₁₈Doc3T/盐/氰基苯凝胶体系在电场作用下发生可逆的颜色.

Synthesis and Gel-forming Properties of a Novel Class of Oligothiophene Derivatives

In order to develop a novel class of low molecular weight organic gels and to gain an insight into the relationship between molecular structure of gel forming compounds and gel forming properties, a novel family of low molecular weight organic compounds containing terthiophene and tetrathiophene, N, N'-dialkyl-5, 5" (2, 2":5, 2"-tetrathiophene)dicarboxamide(DNC₁₈3T), N, N'-dialkyl-5, 5" (3, 3" dioctyl 2, 2":5, 2"-tetrathiophene) dicarboxamide(DNC_n DOc3T, n=5, 8, 16, 18) and N, N'-dialkyl-5, 5" (3, 3dioctyl 2, 2":5, 2":5", 2"-tetrathiophene) dicarboxamide(DNC₁₈ DOc4T), were designed and synthesized. Whereas DNC₁₈ 3Tand DNC₅DOc3Tdid not form gels with organic solvents, DNC_n DOc3T (n=8, 16, 18) and DNC₁₈ DOc4Twere found to form gels with certain organic solvents. These are the first examples of low molecular weight organic gels containing an oligothiophene moiety. It is of interest to note that while DNC₈DOc3Tforms opaque gels with alcohols, such as ethanol and isopropanol, DNC₁₆ DOc3T, DNC₁₈ DOc3Tand DNC₁₈ DOc4Tformed transparent gels with hydrocarbon solvents such as heptane, octane, undecane, and others. It is shown that the intermolecular hydrogen bonding and intermolecular interaction between the long alkyl chain in the Nalkylcarboxamide group as well as the incorporation of an alkyl group at the β position of the thiophene ring play an important role for the formation of gels. The xerogel showed three dimensional networks of fibrous bundle structure. DNC₁₈ DOc3T/benzonitrile gel and DNC₁₈ DOc4T/benzonitrile gel were found to function as a new type of electrochromic materials, exhibiting a reversible color changes on electrochemical oxidation and reduction.