【作者】 刘会军；

【导师】 蒋民华； 陶绪堂；

【作者基本信息】 山东大学 ， 材料学， 2007， 博士

【摘要】 随着现代科学技术的发展,从分子到材料,晶体学和晶体工程学肩负着重要的使命,尤其是在有机光电功能材料的研究开发方面。基于晶体工程学的基本原理,并在晶体学的研究方法和测试手段的帮助下,我们初步建立起了一种新的设计和研究光电功能材料的研究思路,并且成功获得了一些新的有机光电功能材料。主要研究工作总结如下;1、设计、合成了两种具有较大π电子共轭体系的吡啶类苯乙烯型有机晶体材料,利用X-射线衍射等手段解析了它们的晶体结构,并详细分析了它们在凝聚态下的分子形态、堆积方式、分子间相互作用等因素和线性光学性质之间的关系。确定了可以通过适当的分子剪裁来调控共轭体系的程度和分子在凝聚态下的堆积方式,以减少分子间的相互作用来改善和提高有机晶体材料在凝聚态下发光性质的研究思路。为了进一步证明这一思路的可行性,我们合成了另一类新型的有机小分子晶体材料。从分子设计的角度出发,减小分子的共轭程度,以削弱凝聚态下分子间的相互作用,尤其是存在于分子共轭骨架之间的相互作用。该化合物在凝聚态下表现出较强的单光子荧光发射,制作了电致发光器件,初步研究了该化合物的电致发光性能,结果表明该化合物在电致发光方面具有潜在的应用前景。2、吲哚咔唑具有很好的刚性平面结构和丰富的π电子,以及优良的电子离域环境。在生物、化学等诸多领域,吲哚咔唑衍生物已经展现了许多奇特的性质和功能,但作为发光材料的研究却没有引起足够的重视。从分子设计的角度出发,设计、合成了以吲哚咔唑为中心母环,在2,8位衍生双二苯乙烯的直线型结构的大π共轭体系双齿配体。从晶体工程学的角度考虑,用链状硫氰酸镉和双齿配体通过自组装合成了多维链状配位聚合物,将具有大π共轭体系的有机配体分子有效地隔开,消除了配体分子凝聚态下的分子间相互作用,最大限度地减少了其凝聚态下的荧光淬灭效应。同时在配位聚合物中,金属离子对π体系有强烈的诱导效应,可以形成有机无机杂化的分子轨道。这些电子和空间结构的独特效应,大大增强了配位聚合物的荧光发射强度,同时使发射峰发生位移。晶体学研究、线性光谱分析、量子化学理论计算都证实了通过有机无机杂化实现金属离子对π体系有强烈的诱导效应是一种设计强荧光材料的有效方法。3、在线性分子π电子共轭体系有机晶体材料的研究基础上,我们又把苯乙烯共轭体系引入到∧型骨架中,研究其在∧型分子里对于材料结构和性质等方面的影响。在∧型有机晶体材料的研究方面,我们初步取得了一些在合成和结构上有意义的进展;得到了一个有意义的中间体产物并解析了其晶体结构,找到了一种在不对称合成方面可能有应用潜力的合成方法。4、具有纳米孔道结构的多孔结构材料在催化、分离、非线性光学、气体储存、生物模拟、生物探针等领域都具有潜在的应用价值。纳米孔道广泛存在于无机、配合物、金属有机材料中,具有纳米孔道结构的有机晶体材料鲜见报道。我们在研究由∧型双枝分子构筑的有机晶体材料过程中,得到了一种新型具有顺时针螺旋结构的纳米级有机多孔晶体结构材料。孔道的内直径为9.442～16.755(?),一个单胞中孔道的体积是1299(?)~3,占整个晶胞体积的11.62%,可以容纳一般的气体分子和有机小分子等,因此在储氢材料或主客体化学方面有潜在的应用前景。通过单晶X-射线衍射、元素分析、核磁共振、质谱等现代分析手段表征了这一特殊结构,从超分子化学和晶体工程学方面探讨了这种晶体的形成原因,初步得出基于∧型的A-π-D…D-π-A型的特殊分子构型的分子间静电相互作用是形成这种特殊结构的主要原因。这一有意义的结论将有助于设计与合成更多结构奇特、功能多样的纳米多孔有机晶体材料。更多还原

【Abstract】 Molecular and crystal engineering are playing a more and more important role in designing and investigating the photoelectric functional materials.By means of crystallography and the basic principle of crystal engineering,a strategy for designing new photoelectric functional materials has been reported and some new crystal materials were obtained.Based on the research works the following conclusions are got.1.First of all,two kinds of organic crystal materials with largeπ-conjugated system were designed and synthesized.Both molecular crystal structures were characterized by X-ray single-crystal diffraction analysis.And the molecular conformation,molecule stacking and intermolecular interactions in the aggregation state were studied in detail.In addition,their effects on the linear optical properties of the materials were also investigated.It is found that adjusting the range and degree of theπ-conjugated system can reduce the intermolecular interaction.The optical properties of the molecules in the aggregation state could be improved.Following this, a new kind of small-molecule organic crystal material was synthesized.For reducing the length of the conjugated backbone and the degree of the conjugation,the weak intermolecular interaction in the crystal structure is reduced,particularly,the interaction betweenπ-conjugated backbones nearly disappeared.As a result,the new molecule shows very strong fluorescence in the aggregation state.Furthermore,an electroluminescence device using the strong fluorescence crystal material as emitting layer was made.The results show that it has potential application for electroluminescent devices.2.The skeleton of indolo[3,2-b]carbazole is a planar structure possessing abundantπ-electrons and also in an optimized delocalization environment.Its derivatives exhibit different properties,but have seldom been mentioned as luminescent materials.On the other hand,Cd（Ⅱ）-containing coordination polymers have attracted considerable interest owing to the variability in forming bonds with different donors,various coordination modes,and special physical properties of Cd（Ⅱ） ion.By combining a new,large,π-conjugated bidentate ligand,2,8-Bis[2-（2-pyridyl） vinyl]-5,11-di（2-ethylhexyl）-indolo[3,2-b]carbazole（BPVIC）with a[Cd（NCS）₂]_∞, polymer chain,a novel supramolecular coordination polymer,[Cd₂（BPVIC）₂（SCN）₄]_∞, with network structure has been prepared.The crystal structures of the free ligand and the coordination polymer were determined by X-ray single-crystal diffraction analysis and their solid state luminescence was investigated.The experimental results indicated that the luminescence maximum of the coordination polymer is obvious red-shifted compared to that of the free ligand and the luminescence intensity is enhanced significantly.The strong interaction between the ligand and metal in the coordination polymer is one of the important factors for the strong luminescence of the polymer.The other factor is that in the coordination polymer,theπ-πand C-H…πinteractions are eliminated due to the infinite[Cd（NCS）₂]_∞zigzag chain,which acts as a spacer and a controller for the arrangement and alignment of the largeπ-conjugated system.The results indicated that supramolecular assembly is a suitable way to design strongly luminescent materials.3.The styrene-conjugated system has been introduced into the A-shape backbone molecules,and the effects of conformation on the structure and property of the A-shape molecules has been studied.An important intermediate compound and its crystal structure were successfully been obtained and a potential synthesized method for asymmetric molecules was found.Some meaningful developments for the A-shape organic crystal materials have been obtained.4.Crystalline nanoporous materials have received extensive attention due to their potential applications in catalysis,separation,sensors,lasers,gas storage,biological simulation,and so forth.Nano-channels exist widely in inorganic and special metal-organic-framework（MOF）materials.However,purely organic structures with nanometer dimensions are rare,especially,formed with organic rigid molecules. Herein,we report a novel organic nanoporous crystal with unidirectional helical channels of diameter about 1 nm.The novel nanoporous organic crystal is self-assemblied mainly through C-H…πinteractions with a new class of∧-shaped Troger’s base analogues.The results indicate that intermolecular electrostatic interactions can play an important role in the formation of this special crystal although many other factors could influence the crystallization process.The crystal belongs to rhombohedral space group R-₃^-.The internal surfaces of the helical hexagram nano-channels possess a diameter ranging from 9.442 to 16.755（?）.The nano-channels are co-directed and large enough to accommodate some small organic molecules to form new host-guest complexes.The results are useful for the design and synthesis of other new nanoporous organic crystal materials.更多还原