基于苯并[1,2-b:4,5-b']二噻吩的低带隙聚合物的理论研究  

Theory calculations on the novel low-band-gap benzo[1,2-b;4,b']dithiophenebased polymers

作　　者：邓理丹[1] 申明金[1] 曹洪彬[1] 苏宇[1] 

机构地区：[1]川北医学院化学教研室,四川南充637000

出　　处：《计算机与应用化学》2014年第8期955-960,共6页Computers and Applied Chemistry

基　　金：四川省科技厅攻关项目资助课题(04SG022-028);川北医学院科研发展计划项目(CBY13-A-QN29)

摘　　要：采用密度泛函理论,在B3LYP/6-31G(d)水平下,对基于苯并[1,2-b:4,5-b']二噻吩(BDT)为电子供体,thieno[3,4-b]pyrazine(TP),thieno[3,4-b]thiadiazole(TD),dithieno[3,4-b:3',4'-e]pyrazine(DTP)和[1,2,5]thiadiazolo[3,4-e]thieno[3,4-b]pyrazine(TTP)为电子受体的低聚物和聚合物进行了理论计算。为了了解其导电性质,文中不仅计算了二面角、分子内的电荷传输、中心键键长和中心键电荷密度,还分析了核独立化学位移。结果显示:随着聚合链增长,共轭程度不断增加。NICSs值显示:中心环比边环的共轭程度更大。聚合物的能带结构表明:(DTPBDT)_n和(TTPBDT)_n拥有非常低的带隙(分别为0.53和0.40 eV)且拥有比较宽的带宽,因此可以做为潜在的导电材料。In this article, bcnzo[1,2-b;4,5-b＇]dithiophene-based alternating donor-acceptor conjugated oligomers and polymers were studied by the density fimction theory （DFT） at B3LYP level with 6-31（G）. Benzo[1,2-b：4,5-b＇] dithiophane（BDT） is used as donor and thieno[3,4-b] pyrazine （TP）, thieno[3,4-b] thiadiazole （TD）, dithieno [3,4-b：3＇,4＇-e] pyrazine （DTP） and [1,2,5] thiadiazolo [3,4-e] thieno [3,4-b] pyrazine （TTP） are used as acceptor. The torsional angle, intramolecular charge transfer, bridge bond length, electron density at bond critical points （BCPs）, and nucleus independent chemical shift （NICSs） are analyzed and correlated with the conduction properties. The results indicate that the degree of conjugation increases with main chain extension. The NICSs values show that conjugation in the central is stronger than the outer section. The band structure analysis shows that （DTPBDT）n and （TTPBDT）n have narrow band gaps （0.53 and 0.40 eV, respectively） and relatively large bandwidth. Therefore, those polymers are good candidate for conductive materials.

关 键 词：苯并[1 2-b 4 5-b’二噻吩 密度泛函理论 低带隙聚合物 导电材料 

分 类 号：O6[理学—化学] O64