【作者】 尹京花；

【导师】 吴学；

【作者基本信息】 延边大学 ， 有机化学， 2010， 博士

【摘要】 光致变色材料在光信息存储、光转换器件、光开关等领域有广阔的应用前景。其中萘并萘醌类光致变色化合物由于具有独特的耐疲劳性和热稳定性,而备受关注。本文对6-羟基-5,12-萘并萘醌衍生物为研究对象,重点研究了其光致变色反应中异构体和过渡态构型,以及其结构和光致变色性能间的关系,进行了实验结果解释和探讨反应机理；为进一步研究设计高效醌类光致变色材料提供理论依据。本文研究的内容主要包括以下部分1.用密度泛函理论的B3LYP／6-31G方法和从头算的CIS／6-31G方法分别研究了6-羟基-5,12-萘并萘醌及其CH3,C6H5取代衍生物基态和激发态的异构化反应。反应势能面显示,在光异构化反应中化合物M21、M31的基态和激发态虽然都可以构成四能级反应过程,但由于M21异构化过程的活化能较高,使其所构成的四能级反应难以进行,从理论上解释了迁移基团为甲基的M21变色性能低于迁移基团为苯基的M31的实验结果。此外用TD/B3LYP方法在溶剂存在下计算了上述化合物的紫外吸收光谱和荧光发射光谱,计算所得到的光谱数据与实验值基本一致,与光异构化反应的光激发条件相符合,即用紫外光照射至达到光稳态,完成呈色过程：而后用可见光照射至光稳态,完成消色过程。2.为了考察共轭主体上的取代基、母体醌环共轭程度不同对变色性能的影响,对不同取代基及母体醌环共轭程度不同的6-苯氧基-5,12-萘并萘醌衍生物进行了理论研究。共轭程度相同的6-苯氧基-5,12-萘并萘醌衍生物体系中,母体醌环上连接有取代基时分子构型参数基本上没有变化,而对其激发态的正逆活化能有影响。2位甲基取代的衍生物激发态正逆活化能明显增大,表明其光致变色性能将会降低。与萘醌氧原子连接的迁移基团部位C原子杂化类型为sp2杂化时,光异构化反应的活化能将降低,有利于光异构化反应的进行。3.采用量子化学从头算理论在MP2／6-31G(d,p)水平上对2,2’-二甲基-4,4’-联噻唑顺反异构体,trans-2,2’-二甲基-4,4’-联噻唑-CHCl3(Ⅰ),cis-2,2’-二甲基-4,4’-联噻唑-CHCl3(Ⅱ)形成的1：1氢键复合物进行计算研究。结果表明,2,2’-二甲基-4,4’-联噻唑在气相条件下,反式构象比顺式构象稳定。氯仿与2,2’-二甲基-4,4’-联噻唑形成的复合物存在较强的氢键,表现为氮原子的孤对电子与氯仿分子中C—H反键σ轨道的相互作用,另外形成C—H…Cl弱相作用,氢键作用使2,2’-二甲基-4,4’-联噻唑的顺式结构在氯仿溶剂比反式结构更稳定。氢键及环电流效应成功解释了2,2’-二甲基-4,4’-联噻唑分子在氯仿和苯溶剂中核磁共振实验数据的变化。更多还原

【Abstract】 Photochromic materials have wide applications in many fields such as optical storage materials, optical devices, and light-operated switch, ect. Among various photochromic materials, naphthacenequinones is one of the most promising materials because of their unique properties such as fatigue resistance and thermal stability. In this paper, the research are focused on 6-hydroxy-5,12-naphthacenequinone derivatives, involve their isomers and transition state structures in photochromic reaction, as well as the relationship between their structure and photochromic properties. This research can provide a theoretical basis to further design of highly efficient quinone photochromic materials.This paper mainly includes the following sections1. Photoisomerizations of 6-hydroxy-5,12-naphthacenequinone and its derivatives bearing methyl and phenyl group were theoretically investigated with density functional theory method and ab initio CIS method at the B3LYP 6-31G basis set, respectively. The obtained potential energy curves disclosed that a four-state cycle existed in the ground and excited states. It was also found that the activation energy for the methyl transfer was higher compared to the phenyl transfer, which was consistent to the experimental results that the photoisomerization of the phenyl substituted derivative was more rapid than the methyl substituted derivatives. Further hybrid time dependent density functional theory (TD-DFT) was used to investigate the abso rption and fluorescence spectra of these compounds under solvent effect condition. The calculated values were in agreement with the experimental results and excitation condition of photochromic reactions.2. The molecular structure of the compounds has an important effect on its performance of photochromic. In order to investigate the influence of conjugate substituents on the subject and conjugated degree of the parent quinone ring o n the performance of photochromic, the different conjugate substituents and 6-hydroxy-5,12-naphthacenequinone derivatives of different parent quinone ring conjugated are theoretical studied.3.The cis-trans isomers of 2,2’-dimethyl-4,4’-bithiazole,1:1 hydrogen-bond complex (Ⅰ) between trants-2,2’-dimethyl-4,4’-bithiazole and chloroform, and hydrogen-bond complex (Ⅱ) between cis-2,2’-dimethyl-4,4’-bithiazole and chloroform were calculation studied by using ab initio calculation at MP2/6-31 G(d,p)basis set level. The results showed that in the gas phase, trans-2,2’-dimethyl-4,4’-bithiazole was more stable than cis-2,2’-dimethyl-4,4’-bithiazole. There are strong hydrogen-bonds existing in the 1:1 hydrogen-bond complexes, as interaction between the lone pair electrons on the N atom andσ*(C-H) antibonding orbitals in chloroform molecule, as well as weak interaction between C-H and Cl. The existing hydrogen-bonds made cis-2,2’-dimethyl-4,4’-bithiazole more stable in chloroform solvent. Hydrogen-bond and effect of ring current predicted in this theoretical work successfully explain the NMR experimental results.更多还原