【作者】 潘虹；

【导师】 王建武； 赵翠华；

【作者基本信息】 山东大学 ， 有机化学， 2014， 博士

【摘要】 与传统的无机光电材料相比,有机光电材料具有具有重量轻、工艺简单、成本低廉、可制备大面积柔性器件,并且具有更高的发光效率和更宽的发光颜色选择范围等优点。近年来,有机光电材料受到越来越多的关注,并广泛应用于有机电致发光器件、有机光伏电池、有机场效应晶体管、有机激光器以及有机传感器等领域。在有机光电器件中,这些有机光电材料通常是以固体薄膜的形式来使用,但大多数有机光电材料都是在稀溶液中有很强的荧光,而在固态下发生严重的荧光淬灭,从而大大影响了器件的效率。因而设计并合成具有高固态荧光效率的有机化合物具有重要意义。本论文的前两部分所做的研究,就是通过增强分子内的电荷转移和抑制固态分子紧密堆积来抑制固态荧光的淬灭,从而得到具有高固态荧光效率的有机共轭分子。在这些有机光电材料中,多并苯类及杂环多并苯类化合物,以其特殊的电子离域特征,在有机光电器件中尤其是有机场效应晶体管(OFETs)中具有重要的应用价值,一直受到受到广泛的关注和研究。目前对这类线性稠环化合物的研究主要集中在多并苯类和含硫原子的线性稠杂环共轭分子。而对含氮原子的线性稠杂环类化合物则相对较少,而含氮桥头的稠杂环类共轭分子更是鲜有报道。本论文的最后两部分的内容,就是利用新型串联反应合成了一系列氮桥头芳杂五环并吡啶类化合物,以及通过分子内的对称反应合成结构新颖的含氮桥头的多并环稠杂环类共轭分子。第一部分,我们以较小的π-共轭体系联苯作为共轭桥,在其o,o’-位分别引入硼取代基和氨基,分别作为吸电子基团(A)和给电子基团(D)。由于硼取代基和氨基之间的距离较近,受激分子可通过空间实现分子内的电荷转移。我们还合成了两个取代基位于不同位置的联苯参照物,并对这系列化合物的性质进行了多项表征。研究发现,当硼取代基和氨基分别位于o,o’-位时不仅具有较大的发射波长和Stokes位移,并且其固态荧光效率达到了0.86。当该化合物与氟离子作用后其发射波长发生显著蓝移,可作为比率荧光探针。第二部分,我们通过Pd(0)催化的Suzuki-Miyaura偶联反应得到了一系列对称的和不对称的含二米基硼取代基的2,1,3-苯并噻二唑(BTD)类衍生物。我们对它们的性质进行了多项研究,包括X-射线单晶衍射、稀溶液和固态下的紫外吸收和荧光发射、密度泛函理论计算(DFT计算)、热重分析(TGA)以及氟离子滴定等。由于二米基硼取代基的大位阻效应抑制了固态分子的相互作用,这系列化合物不仅在溶液中,而且在固态下均有很强的荧光。第三部分,我们将JWang’s串联反应中的γ-溴代-α,β-不饱和碳酸酯换成Y-溴代-α,β-不饱和腈,与一系列芳基取代的吡唑醛,在碳酸钾作用下反应,得到了一系列芳基取代的吡唑并[1,5-a]吡啶类衍生物。同时在吡啶环上的4-位引入了强吸电子基团腈基,增强了分子内的电荷转移,并可通过还原对腈基进行进一步的修饰。我们的工作为合成含腈基取代氮桥头芳杂五环并吡啶类化合物提供了一个简单高效的方法。第四部分,我们期望通过1,2,4,5-苯四胺发生一系列对称的反应得到含桥头氮的五并环稠杂环共轭分子。但由于中间产物的溶解性极差,导致对产物的提纯及分离不易进行。因而我们采用了分步合成的方法,以4,7-二溴-2,1,3-苯并噻二唑为起始原料,合成了一系列4,7-二苯基-吡啶并[1,2-a]苯并咪唑类化合物。另外对4,7-二溴-2,1,3-苯并噻二唑进行硝化、偶联、还原,得到相应的二胺或四胺衍生物,由于取代基效应影响,进一步的合环反应条件正在探索当中。更多还原

【Abstract】 Compared with conventional inorganic optoelectronics materials, organic optoelectronics materials have attracted substantial interests and investigation in recent years, due to their advantages, such as light-weight, low-cost, simple-process, flexibility and reel-to-reel coating applied in large area, higher luminous efficiency and wider choice of luminous color. They can be widely utilized in the field of organic light-emitting diodes (OLEDs), organic photovoltaic cells (OPVs), organic field effect transistor (OFETs), organic solid-state lasers and organic fluorescent sensors.In these organic photoelectric devices, the organic emissive materials are usually used in the forms of aggregate or thin solid films. As we known, most of the emissive materials are highly emissive in dilute solution, but severe fluorescence quenching in the solid state as the result of intermolecular interactions, thus greatly affecting the properties of materials and efficiency of devices. Therefore the rational design of such highly emissive organic materials in solid state is still a challenging and interesting issue. The front two parts of this dissertation are about the design and synthesises of the novel highly emissive organic π-conjugated molecules in solid state through promoting the intramolecular charge transfer and suppressing the intermolecular interaction.In these organic photoelectric materials, the polyacene and heteroacenes have attracted extensive attention and research due to its unique property of linear π-electron delocalized. Recently, extensive efforts have brought significant progress in the development of high performance optoelectronic devices based on these polyacenes and heteroacenes, especially to development the high performance organic field-effect transistors (OFETs). Recently, mostly of the research is mainly focused on the polyacene and sulfur-containing heteroacenes, while only a few reports is about nitrogen-containing heteroacenes, and even rarely reported on the nitrogen-bridge-containing heteroacenes. So the latter two parts of this dissertation are about the synthesises of a series of pyrazolo[1,5-a]pyridine derivatives with nitrile group substituted at the pyridine ring and further to obtain nitrogen-bridge-containing heteroacenes.The first part of this dissertation, we have designed and synthesized a new class of organoboron compounds containing a boryl and an amino group as acceptor and donor at the o,o’-positions of biphenyls. The distance between the boryl group and the amino group is much shorter than those of the through-space CT emitting organoboron compounds reported so far. We also synthesized two reference compounds with only the amino group or both the boryl and the amino group at the p-position of biphenyls. We find that the biphenyl derivative with o,o’-substituent not only have longer emission wavelength and large Stokes shift, but also have high fluorescence quantum efficiency (ΦF=0.86) in solid state. In addition, binding of the fluoride ions results in the remarkable blue shift and color change of the fluorescence, enabling colorimetric and ratiometric fluoride ion sensing.The second part, one symmetrical and two unsymmetrical dimesityboryl-substituted2,1,3-benzothiadiazole (BTD) derivatives have been prepared through Pd(0)-catalyzed Suzuki-Miyaura coupling reaction. These compounds are characterized by X-ray crystallography, UV-vis and fluorescence spectroscopy in solution and in solid state, DFT calculations, thermogravimetric analysis (TGA) and titration of fluoride ion. All these compounds display intense fluorescence not only in solution but also in the solid state due to steric bulkiness of the boryl group, which is effective to suppress the intermolecular interaction in the solid state. In addition, the symmetrical boryl-substituted BTD displays prompt fluorescence responses to fluoride ions with high sensitivity through the complexation of the boron center with fluoride, demonstrating its potential utility as fluorescent sensor for fluoride ions.The third part, we have developed the novel JWang’s tandem reaction to synthesize several pyrazolo[1,5-a]pyridine derivatives with nitrile group substituted at the pyridine ring by condensing the4-bromobut-2-enenitrile with pyrazole-aldehydes in mild conditions. The obtained novel compounds are particularly interesting molecules and can be further modified on the nitrile group to construct potential biological activity molecular.The fourth part, we try to synthesize bridged-nitrogen five-cyclic heteroacenes from benzene-1,2,4,5-tetraamine. However, it is difficult to purify and separate the intermediate product due to the poor solubility. Thus we used4,7-dibromo-2,1,3-benzothiadiazole as a starting material to synthesize4,7-diphenyl-pyrido[1,2-a]benzimidazole derivatives. In addition, the4,7-dibromo-2,1,3-benzothiadiazole goes by nitration, coupling and reduction to give the corresponding diamine or tetraamine derivative, and the reaction conditions of next cyclization reaction is on exploring.更多还原