新型低聚噻吩衍生物的合成及其凝胶化性能研究

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

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(DNC1 83 T) ]、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(DNCn DOc3 T,n=5 ,8,1 6,1 8) ]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(DNC1 8DOc4T) ].研究结果表明 ,DNC1 83 T和 DNC5DOc3 T同有机溶剂不形成凝胶 .DNCn DOc3 T(n=8,1 6,1 8)和 DNC1 8DOc4T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 (1 H NMR)、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 ,DNC1 8Doc3 T/盐

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  distearyl 5,5' (2,2∶5,2' terthiophene)dicarboxamide(DNC 18 3T), N,N  dialkyl 5,5' (3,3' dioctyl 2,2∶5,2' terthiophene) dicarboxamide(DNC n DOc3T, n =5, 8, 16, 18) and N,N  distearyl 5,5 (3,3 dioctyl 2,2∶5,2'∶5',2 tetrathiophene) dicarboxamide(DNC 18 DOc4T), were designed and synthesized. Whereas DNC 18 3T and DNC 5DOc3T did not form gels with organic solvents, DNC n DOc3T( n =8, 16, 18) and DNC 18 DOc4T were 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 DNC 8DOc3T forms opaque gels with alcohols, such as ethanol and isopropanol, DNC 16 DOc3T, DNC 18 DOc3T and DNC 18 DOc4T formed 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 N alkylcarboxamide 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. DNC 18 DOc3T/benzonitrile gel and DNC 18 DOc4T/benzonitrile gel were found to function as a new type of electrochromic materials, exhibiting a reversible color changes on electrochemical oxidation and reduction.