【作者】 洪巍；

【导师】 朱道本；

【作者基本信息】 复旦大学 ， 有机化学， 2008， 博士

【摘要】 有机功能材料是有机合成、物理化学和电子学的交叉研究领域,它将合成的有机分子应用于光电器件,为信息技术的发展开辟了新天地,因此得到广泛的重视。本论文分别从有机电子给体和有机场效应半导体两个子方向切入这一领域,设计合成了多种新型分子,对它们进行理论计算和性质研究,制备了相应的分子器件,测试了材料的性能;并试图探讨分子结构和性能之间的内在联系,以进一步设计性能更好的有机功能材料。主要内容如下:1.论文第一部分（第二章）,合成了12个σ键非共轭联接的含2-6个TTF单元的枝状和环状新型有机电子给体1a-b、2a-b、3a-b、4a、6’、7、8、9a-b,并经核磁、红外、高分辨质谱确认了它们的结构。合成了碘代前体19和23,可以应用于引入TTF单元的亲核取代反应。2.初步优化计算了新型电子给体的构型,发现含多个TTF单元的线形给体同侧TTF单元一般取交叉垂直排列;环形给体TTF单元沿中心呈弯曲扇叶状排列。用循环伏安法研究了它们的电化学性质,发现各线型电子给体均出现了二组可逆或准可逆的特征氧化还原峰,说明TTF单元间的相互作用很小,与非共轭键相连接的结构相吻合。从氧化还原电位来看,新型给体均具有和经典给体BEDT-TTF相似的给电子能力。发现含三个TTF单元的大环给体8具有分阶段的二级氧化过程。研究了含5-6个TTF单元的电子给体2a和4a的LB成膜性能,发现均能形成质量较高的单分子膜,崩溃压高于以前的研究结果,为制备LB薄膜器件提供了依据。3.论文第二部分（第四章）,研究了一类同时含硫和氮原子的并五苯类似物——二（苯并吩噻嗪）并吡咯（PBBTZ）环系,第一次将其应用于OTFT器件。合成了PBBTZ环系化合物1-3并比较研究了类似物4,通过结构、光学、热力学、电化学和器件研究,发现PBBTZ是一类合成简捷、分离方便、在环境中稳定的p型半导体材料。电化学研究表明,PBBTZ衍生物的HOMO能级与用作场效应晶体管电极材料的金的功函能较好匹配。X射线单晶衍射表明,化合物1的呈γ-鱼骨状面对面堆积,有利于形成高效的电荷传输:化合物3由于取代烷基的影响,单晶结构为夹心鱼骨状堆积,柱内层间距大于化合物1,可能使相应器件性能降低。器件测试表明,1-4的薄膜场效应晶体管均为p型,当基底温度为60℃时,1达到最好的器件性能,平均迁移率可达0.34 cm² V^-1s^-1,开关比为7×10⁶-3×10⁷,综合性能在已报道类并五苯结构半导体材料中处于前列。跟踪测试表明器件在空气中显示了良好的稳定性。薄膜形貌AFM和XRD测试表明,1薄膜场效应器件的高性能来源于膜内分子的有序排列。基底温度为100℃时,1的场效应迁移率仍在10^-2cm²V^-1s^-1量级。化合物2和3吡咯氮上的取代基看来影响了有序排列,降低了薄膜场效应器件的性能。化合物3溶解性较好,有希望用于溶液成膜的器件,并在光电流测试中显示出应用于有机太阳能电池的潜力。4.论文第二部分（第五章）中,还设计合成了含氟基团取代的PBBTZ环系衍生物5和6,研究了它们的合成和光谱、热力学、电化学性质,测定了6的单晶结构。通过紫外光谱和电化学数据,估算了它们的能级和能隙。发现含氟基团的引入,有效降低了PBBTZ的HOMO-LUMO能级,其中苯环上的三氟甲基对能级降低贡献较大,化合物5热稳定性好,吡咯氮上氟碳链改善了化合物6的溶解性。目标化合物是一类具有前景的n型半导体材料。更多还原

【Abstract】 Organic functional materials,which involve the fields of organic synthesis,physical chemistry and electronics,have attracted wide attention because of their potential use in photoelectric devices.In this dissertation,new organic electron donors and organic semiconductors were designed and synthesized.By studying and comparing their physical and chemical properties,as well as the theoretical calculation,we tried to understand the relationship between molecular structures and properties.The main contents and results are listed as follows:1.In the first part of this dissertation（ChapterⅡ）,twelve novel oligomeric electron donors（1a-b,2a-b,3a-b,4a,6’,7,8,9a-b） containing two to six tetrathiafulvalene（TTF） units were synthesized.Their structures were assigned by NMR spectroscopy,infrared spectrometry and high resolution mass spectra.New precusors 19 and 23 were also developed in the synthetic route,which should be suitable for other synthetic transformations for the incorporation of TTF units.2.The configurations of novel donors were optimized by preliminary calcultion.TTF units in the linear oligomeric donors were found packing cross-vertically,while those in the macrocyclic donor arranged fan-shapedly around the symmetric center.The electrochemical properties were determined by cyclic voltammetry.All the linear or dendritic donors exhibited two pairs of nearly ideal reversible redox waves.This result could be well explained by the fact that they are non-conjugated oligomers linked byσ-bonds,and therefore little interactions occur among the TTF units.The redox potentials indicated that all of the new electron donors possessed similar electron-donating properties as BEDT-TTF.It was also found that the trisannulated macrocycle 8 exhibited a stepwise second oxidation process.The LB-film performance of pent-TTF and hex-TTF donor 2a and 4a was studied.Both molecules could form qualified monolayer,and their critical surface pressures were higher than former results.3.In the second part of this dissertation（ChapterⅣ）,an analogue system of pentacene, 6-substituted-6H-Pyrrolo[3,2-b:4,5-b’]bis[1,4]benzothiazine（PBBTZ）,was applied as field-effect transistors for the first time.PBBTZ derivatives 1-3 and a related compound 4 were facilely synthesized and characterized.Their optical properties were studied by UV-Vis and fluorescence spectroscopy,and electrochemical properties were investigated by cyclic voltammetry（CV）.Good thermal stability was observed by thermogravimetric analysis.X-ray analysis revealed a coplanar structure and a column stacking in the single-crystal of the N-unprotected PBBTZ 1,and a sandwich-herringbone arrangement of the molecules of compound 3.OTFT characterizations show that 1-4 were p-type organic semiconductors.The performance of these devices displayed good reproducibility at ambient conditions. When the devices of 1 were fabricated on OTS-treated SiO₂/Si substrate at 60℃,the best performance was achieved,with the average hole mobility as high as 0.34 cm² V^-1 s^-1 and the on/off ratio about 7×10⁶ - 3×10⁷.This performance was resulted from the well-ordered molecular packing as revealed by XRD and AFM analysis. When the substrate temperature was enhanced to 100℃,the mobility of the devices of 1 was still promising.The substitutes in 2 and 3 might retard the efficientπ-πinteracitons,resulting in decreased charge transport properties.Compound 3 was well soluble for low-cost fabrication with solution-processed technology,and it was also demonstrated the potential use in solar cell by photocurrent detection.4.Two fluoroalkyl substituted PBBTZ derivatives 5 and 6 were designed（ChapterⅤ）, synthesized and characterized.Their optical properties were studied by UV-Vis and fluorescence spectroscopy,electrochemical properties were investigated by cyclic voltammetry（CV）,and thermal stabilities were evaluated by thermal gravimetric analysis（TGA）.X-ray single-crystal analysis revealed a sandwich-herringbone arrangement of the molecules of compound 6.The energy gaps of 5 and 6 were taken directly from spectroscopic measurements.Their LUMO and HOMO energy levels were estimated by electrochemical performance.The introdution of trifluoromethyl decreased their energy levels effectively.Compound 5 exhibits higher thermal stability,while compound 6 exhibits better solubility in many common organic solvents.The low energy levels enable them to be environmentally highly stable,and render both of them to be protential n-type semiconductors.更多还原