基于三环非经典噻吩的低能带隙低聚物的分子设计及DFT研究  

The molecular design and DFT study on the small band-gap oligomer involving tricyclic nonclassical thiophene as a building block

作　　者：傅杨武[1] 

机构地区：[1]重庆三峡学院化学与环境工程学院,重庆404100

出　　处：《计算机与应用化学》2013年第2期137-140,共4页Computers and Applied Chemistry

基　　金：重庆三峡学院重点项目(11ZD-10);国家自然科学基金(21073144)

摘　　要：以[1,2,5]噻重氮并[3,4-b]噻吩并[3,4-e]吡嗪(TTP)为受体,以噻吩并[3,2-b]噻吩(TT)、噻吩(Th)、吡咯(Py)和呋喃(Fu)为供体,设计了四类供体-受体型共轭低聚物。采用杂化的密度泛函方法(B3L,YP),研究了六类低聚物的电子结构和性质。AIM分析显示,随着聚合度增加,体系共轭程度增强。随着聚合度增加,低聚物的HOMO-LUMO能级差逐渐减小,电离能降低,电子亲和势增大。Py不但是一个强的电子供体,也是一个潜在的氢键供体。在含Py结构单元的低聚物中,由于分子内氢键的存在使这类低聚物具有较大的分子内电荷迁移值。所设计的4种基于TTP的四聚体均具有较小的HOMO-LUMO能级差(<0.5 eV),因此其相应的聚合物的能隙会更小,可能是潜在的导电聚合物材料。Four types of donor-acceptor conjugated oligomers were designed by choosing [1,2,5]thiadiazolo[3,4-b]thieno[3,4-e]pyrazine as the acceptor and thieno[3,2-b]thiophene （TT）, thiophene （Th）, pyrrole （Py） or furan （Fu） as the donor unit. The B3LYP method is employed to investigate the electronic structure and properties of the designed oligomers. The AIM topological analysis analysis show that the conjugational degree is increased with main chain extension and thus leads to a decrease in HOMO-LUMO energy separation. The vertical ionization potential decrease and the vertical electron affinity of these oligomers increase with an increase in polymeric number. It is also found that the intramolecular hydrogen bond plays a crucial role on the geometric and the intramolecular charge transfer of the TTP-based oligomers. The unusually large intramolecular charge transfer caused by the intramolecular hydrogen bond reveals that pyrrole is not only a strong electron donor but also a potential hydrogen bond donor. The theoretical results suggest the corresponding copolymers of the designed oligomers should be the good candidates for conducting materials due to the narrow HOMO-LUMO energy separation （〈 0.5 eV）.

关 键 词：三环非经典噻吩 低聚物 分子设计 电子性质 

分 类 号：O641[理学—物理化学] O621.13[理学—化学]