【作者】 薛建强；

【导师】 吴飞鹏；

【作者基本信息】 中国科学院研究生院（理化技术研究所） ， 有机化学， 2009， 博士

【摘要】 在双光子聚合敏化染料的设计合成中,结构与性质的关系一直是研究的重点。本论文研究了电子与空间效应对染料双光子吸收和光敏引发性质的关系,通过研究不同取代位置,取代基团和支化效应来研究染料结构与性质的关系,为进一步设计开发高效的双光子聚合敏化引发染料提供理论依据。同时进行高效双光子聚合光敏引发体系的设计及优化,研究了染料在双光子聚合中的应用。1.研究了多支结构中电子与空间效应对染料双光子吸收的影响,证明电子耦合是多支化合物双光子吸收截面非线性增加的根本原因。合成了一个系列键接中心为非共轭基团的多支苄叉环戊酮染料(T1-T3),与相应的键接中心为三苯胺基团的多支染料1-3进行对比研究。表明T2和T3的功能团之间无电子耦合和振动耦合效应,通过支化增加化合物的功能团数只是简单增加功能团的数密度,而2和3与单支化合物相比,光物理性质则表现出明显的耦合增强效应,表明共轭键接中心和电子耦合效应对耦合增强是不可或缺的。此外,通过单光子聚合实验证明电子耦合效应同样有利于增加多支化合物的光敏引发效率。2.研究了电子效应对不同取代香豆素/苄叉环戊酮染料双光子敏化引发性质的影响,发现通过香豆素基团的3位与环戊酮桥接的染料具有更高的双光子吸收和敏化引发性能。合成了两种含香豆素功能团的苄叉环戊酮类染料T4和T5,其分别通过香豆素基团的4位和3位与环戊酮桥接。对它们的光物理和光化学性质进行了系统的研究。并通过量化计算的方法优化了染料的基态构型,计算了其垂直激发能。结果表明桥接位置不同,两种染料的构型、电荷分布和电荷密度存在较大差异,T5具有较好的平面性和共轭程度,较大的双光子吸收截面和更好的双光子光敏引发性能;T4的共轭程度和平面性均较差,但其与引发剂的电子转移自由能低,具有更好的单光子光敏性能。3.利用上述研究成果,设计合成了3位取代的双香豆素环戊酮染料T6,证明其具有很好的双光子吸收和光聚合引发能力,优于T5和常用高效光敏剂BDMA。结合量化计算,表明其双光子吸收截面增加的原因主要为:香豆素环的引入在保持分子刚性的情况下有效的延长了共轭链的长度。而香豆素和环戊酮基团的协同作用有助于提高染料的光敏引发效率。4.开发了一种无需其它引发剂,将苄叉环戊酮染料直接作为三线态引发剂的双光子聚合材料体系。将几种含香豆素功能团的苄叉环戊酮类染料应用于双光子聚合,表明其都可直接用作双光子引发剂,表现出很好的引发性能,可有效引发丙烯酸酯类单体聚合。此类双光子聚合材料体系具有低的引发组分含量和低的引发聚合阈值,且聚合分辨率高,聚合物中小分子残留低。利用此树脂通过双光子聚合成功制作了二维和三维纳米微结构,说明这几种染料及本研究中的树脂在双光子聚合方面都有着很高的应用前景。更多还原

【Abstract】 Structure-property relationship was the focal point in the design and synthesis of high efficient two-photon polymerization (TPP) sensitizers. Electronic and vibronic contributions to two-photon absorption and photosensitizing efficiencies of novel benzylidene cyclopentanone dyes were studied in this thesis. Structure-property relationship was revealed by investigating the effects of the substituent position, substiturent group and branching structure of dyes on their properties. These results provide useful strategies for the design of novel two-photon initiators or sensitizers. Also, a high efficient sensitize-initiating system of TPP was designed and optimized. The application potentiality of these dyes in TPP was proved.1 Electronic and vibronic contributions to cooperative enhancement of two-photon absorption in multi-branched structures were studied, and electronic coupling was confirmed the crucial reason for the enhancement. A series of multi-branched benzylidene cyclopentanone dyes with a non-conjugated central moiety (T1-T3) were synthesized. Their properties were studied in comparison with corresponding triphenylamine derivatives (1-3). No electronic and vibronic coupling effects were observed in T2 and T3. It means that to increase the branch number only increases the number density of chromophores. On the contrary, cooperative enhancement of TPA was observed in 2 and 3 comparing to 1, which confirmed the electronic coupling was the crucial reason for the enhancement. Furthermore, the photosensitizing efficiencies of these compounds were investigated by one-photon polymerization (OPP) and the result indicated the electronic coupling effect was also beneficial to their photosensitizing efficiencies.2 Electronic contributions to two photon sensitizing or initiating efficiencies of coumarin/benzylidene cyclopentanone dyes were studied. Two novel benzylidene cyclopentanone dyes (T4 and T5) containing coumarin moiety were synthesized. Their bridging positions were the 4 and 3 positions of coumarin moiety, respectively. T5 was found to exhibit larger two-photon absorption cross-sections (TPACS) and higher two-photon sensitizing efficiencies. Also, their ground state configurations were optimized and excited states properties were calculated by quantum chemical calculations. It showed that their ground state configurations, charge distributions and charge densities were quite different. T5 shows better planar configuration and conjugated properties, exhibiting larger TPACS and higher two-photon sensitizing efficiencies. Contrarily, the configuration of T4 is twisted; it exhibits lower electron transfer free energy with initiator and higher sensitizing efficiencies in OPP.3 A novel bicoumarin/cyclopentanone dye (T6) was designed and synthesized based on the above-mentioned study. Its bridging point was 3 position of coumarin moiety. The novel dye showed higher photosensitizing efficiency and larger TPACS compared to T5 and common used photosensitizer BDMA (2,5-bis-[4-(dimethylamino)-benzylidene]-cyclopentanone). Combined with quantum chemical calculations, the main factor of its increased TPACS was confirmed to the introduction of coumarin moiety which increased the conjugated length while maintaining the rigid structure of T6. Furthermore, the cooperative effect between coumarin and cyclopentanone groups was found beneficial in the sensitizing efficiencies of dyes.4 A kind of TPP resin was designed by using benzylidene cyclopentanone dyes as one component initiator directly. All benzylidene cyclepentanone dyes containing coumarin moiety were proved that they could be used as photoinitiators directly in TPP and exhibited high initiating efficiencies to initiate acrylate monomers. Only small dosages of initiators were needed in these resins. Also, their threshold energies were very low. 2D and 3D nanopatterns with high resolution and low small molecule residues were successfully fabricated by TPP, which demonstrated extensive application prospects of these dyes and the corresponding resins in three-dimensional microfabrication and high-density optical data storage.更多还原