【作者】 陈晨；

【导师】 郑健禺；

【作者基本信息】 南开大学 ， 有机化学， 2013， 博士

【摘要】 为了理解和模拟光合作用,最终实现太阳能的有效利用,电子/能量给受体体系的构筑成为近年来的重要研究领域之一。大量的给受体体系通过多种多样的连接方式来实现高效的能量转移或电子转移过程。新型的桥连方式和新颖给受体单元的引入不但能赋予体系全新的性能,还可以促进人们更深入地理解电子/能量转移过程的机制,以探寻更具实用价值的分子器件和功能材料。富勒烯是良好的电子和能量的受体,卟啉和咔咯是优异的电子和能量的给体。为进一步拓宽上述功能分子在这一领域的应用,本文从构筑新型共价键连方式、新型超分子作用方式以及新型给体单元三个角度制备了三类新颖的电子与能量给受体体系,并对其性质进行了研究。(1)设计合成了新型的N连接的二茂铁/卟啉-富勒烯[60]二元体系,并成功的分离出[5,6]-开环和[6,6]-闭环亚氨基富勒烯两种异构体。电化学测试表明,开环异构体中的生色团(二茂铁/卟啉)比闭环异构体更容易被氧化。这是由于在闭环异构体中,桥连氮原子与富勒烯的共轭程度更大,因此降低了其对N取代芳基的给电子能力所致。瞬时吸收光谱测试表明,在卟啉-富勒烯体系中,开环异构体具有较长的电荷分离态寿命。本研究内容首次实现了利用富勒烯的不同共轭方式(开环或闭环)来影响给体的性质,进而调控了整个给受体体系的功能,这为设计可调控的电子转移体系和富勒烯材料提供了新的思路。(2)首次通过超分子方式构筑了咔咯-富勒烯给受体体系。证实了钴咔咯与C60和C70在溶液中有明显的相互作用。通过共结晶单晶结构研究了钴咔咯与C60和C70在固态下相互作用方式。对双咔咯主体分子与富勒烯超分子作用的研究结果表明,协同效应能够明显地增强咔咯体系对富勒烯的结合能力,这为进一步构筑咔咯-富勒烯超分子电子或能量转移体系奠定了基础。(3)合成了一类新颖的电子和能量给体分子：meso-meso直接键连卟啉-咔咯杂化体。通过X-射线单晶衍射技术对其结构进行了研究。吸收光谱测试结果表明,这种杂化体首次实现了不同类型大环分子之间强的激子耦合作用。发射光谱和荧光寿命测试结果表明,在卟啉和咔咯之间存在可逆的能量转移过程。更多还原

【Abstract】 The success of nature in converting inexpensive, non-polluting and inexhaustible sunlight into energy has stimulated investigation of this natural process in order to emulate it. Numerous electron/energy donor-acceptor systems have been constructed through altering linkage modes or employing novel donors and acceptors in order to get a better understanding of the photosynthetic process.Fullerenes are good electron and energy acceptors, while both porphyrins and corroles are excellent electron and energy donors. In this dissertation, we respectively constructed three kinds of hybrids based on the above functional molecules. Firstly, we realized a novel covalent bridge (one nitrogen atom) in porphyrin-fullerene hybrids. Secondly, we reported the first example of non-covalent corrole fullerene hybrids through supramolecular interaction. Thirdly, we obtained a new kind of electron/energy donors, meso-meso directly linked porphyrin-corrole hybrids.1. N-linked ferrocene/porphyrin-fullerene dyads have been prepared and two isomers were separated successfully. Results revealed that chromophores connected to [5,6]-open isomers are more easily oxidizable than that attached to [6,6]-closed isomers. We suppose that the engagement between nitrogen lone-electron pair and the delocalized π-system of fullerene should exist in both [5,6]-open and [6,6]-closed isomers, but the extent of engagement should be larger in [6,6]-closed isomer. As a result, the lifetime of charge-separated state is much longer in [5,6]-open isomer. This work suggests that a perturbation of the π electrons of the fullerene can exactly affect electronic properties of N-substituted aryl groups through the bridge nitrogen atom, and will make fullerene-based materials an extensive application in functional materials.2. The supramolecular interactions between cobalt corroles and fullerenes (C60and C70) have been systematically explored both in solution and the solid state for the first time. It is very appealing that cobalt corrole monomers can form stable complexes with fullerenes in solution. Further results from bis-corroles suggest a realizable way to construct powerful complexes of corroles and fullerenes with the aid of cooperative effect. This work will broaden the application of corroles in supramolecular chemistry and lead to the supramolecular corrole-fullerene electron/energy transfer systems.3. meso-meso directly linked porphyrin corrole hybrids have been successfully prepared as novel electron/energy donors. Crystal structure and calculation results show that porphyrin and corrole moiety in the dyads adopt orthogonal conformations, which results in minimizing the conjugate of neighboring chromophores. Obvious split Soret bonds observed in absorption spectra reflect the existence of strong exciton coupling between the adjacent porphyrin and corrole. Luminescence properties of the freebase dyad indicate that reversible energy transfer should exist in the dyad.更多还原