【作者】 陈强；

【导师】 郑健禺；

【作者基本信息】 南开大学 ， 有机化学， 2014， 硕士

【摘要】 卟啉是一类具有平面结构的大环芳香化合物,它具有许多特殊的性质,比如优异的光电性能、催化性能、生物活性等,这使其在材料、催化、医药、分析等领域受到了极大的关注。卟啉类化合物的性质受其周边取代基团的影响较为明显,为了得到特定结构的卟啉往往需要开发并应用卟啉周边的特征性反应来进行卟啉的后修饰(post-modification).因而,卟啉周边后修饰方法研究一直是最近几年国内外科学家关注的研究课题之一。本论文在前人已有研究的基础之上,开展了以下几方面的工作：1.综述了最近几年卟啉化学的研究进展,包括卟啉化合物的结构、性质、合成及应用。卟啉的结构决定了其性质,卟啉大环的性质可以通过对其中心引入配位金属和周边共价修饰两种方式来进行调节。相对于金属化的方式,周边后修饰方法更加具有应用价值,因为种类繁多的有机官能团能够赋予卟啉化合物更加丰富多变的性质,以满足人们对新颖卟啉类化合物的需求。本文重点介绍了卟啉类化合物修饰的三种方式,即p-位修饰、meso-位修饰和芳环上的修饰。2.本文探索了利用芳基亲核取代反应(SNAr)来对卟啉中位(meso-位)进行修饰的方法。该方法无需催化剂的参与,反应过程中使用meso-溴代镍卟啉为原料,在碳酸铯的存在下以DMF作为溶剂,加热反应即可高效地得到中位取代的卟啉衍生物。该反应具有非常宽的底物适用范围,能够与苯酚类、饱和醇类、硫酚类、饱和硫醇类、1,3-二羰基类化合物以及金属有机化合物类底物(如金属锂试剂)发生反应,在最优化反应条件下,能够高效地得到对应的目标产物。除此之外,我们还发现该反应受中心金属种类影响显著,对于meso-溴代自由卟啉,它能够高效地跟苯酚类、苯硫酚类以及硫醇类直接反应生成meso-芳氧基、芳硫基以及烷硫基取代的卟啉衍生物。当往卟啉中心引入锌离子之后,反应活性受到抑制而不能发生此类反应；而往卟啉中心引入铜或镍离子后,反应活性明显提高。3.本文首次利用芳基亲核取代反应原理高效地制备了,meso-氟代卟啉。通过对反应速率的测定,发现meso-硝基以及卤素(F,Cl,Br,I)取代的镍卟啉都能够跟苯酚发生这种类型的取代反应,而且反应速率遵循以下规律：F>Cl>NO2> Br>I。这一特征与芳基亲核取代反应过程的加成-消除机理反应活性规律一致,我们推测此反应经历的是经典加成-消除机理,也即Meisenheimer复合物过程。4.本文共合成了36种未见文献报道的新型单卟啉衍生物以及3种双卟啉衍生物,其结构均通过了1H NMR、13C NMR、HR-MS等手段进行了表征。3种类型的单金属卟啉均可以在浓硫酸的存在下实现脱镍,并且新形成的C-X(X=O,S,C)键不受到影响,这进一步扩展了该反应的应用范围。同时,本文也分别对新合成的这3类化合物(meso-O, S,C取代卟啉)的紫外-可见吸收、荧光光谱等光物理性质进行了研究,发现通过meso-位修饰,能够直接影响卟啉芳环分子上的电子云分布,进而改变其光学性能。更多还原

【Abstract】 Porphyrin is a kind of macrocyclic molecular with large conjugated aromatic structure. This kind of compounds and their derivatives have attracted numberous atterntion from researchers in the areas of materials, catalysis, medicine and analysis because of their inherently excellent photoelectron properties and catalytic activities, as well as bioactivities. The performances of porphyrin derivatives are strongly affected by peripherally substituted functional groups and many modification strategies are eagerly needed to get access to these new structures. Post-modification of porphyrin core proves to be one of the most efficient methods to achieve this goal. Thus, in recent years, peripheral modification of porphyrins has become an attractive research topic among chemists all over the world. Based on the previous research, the topics of this thesis are mainly focused on these aspects:1. We have reviewed recent research progress in porphyrin chemistry, including their structures and properties, preparation methods and practical applications. The functions of porphyrin derivatives are determined by their properties, which could be modulated by central coordination metal ions and substituent groups on the peripheral. Compared to the methods of central metallization, directly peripheral modification of porphyrine core possesses higher practical value, since numberous organic functional groups would provide a lot of new porphyrins to fufill people’s increasing demands for novel compounds. Our attention are focused on the most widely applied peripheral modification ways, which means β-position modification strategies, meso-position modification strategies, as well as functionalization of aromatic ring on porphyrin core.2. In this thesis, we have studied a facial method to achieve meso-position functionalization of porphyrin via aromatic nucleophilic substitution reaction (SNAr). meso-Substituted (O, S, C) porphyrins could be obtained in high yields by heating the solution of bromoporphyrin in DMF using soft nucleophiles as substrates, with Cs2CO3as addictives in the absence of transition metal catalysts. This reaction could be applied to a large range of substrates, such as phenol derivatives, aliphatic alcohols, thiophenol derivatives, thiols derivatives,1,3-dicarbonyl derivatives and carbon anions. The desired meso-substituted porphyrins could be obtained in high yield under the optimized conditions. In addition, we have also observed the reactivity was strongly affected by central coordinated metal ions, and meso-bromoporphyrin (M=2H) could be reacted with phenol, phenyl mercaptan as well as aliphatic thiol derivatives to form meso-substiuted-porphyrin. When Zinc (II) ions were inserted into the porphyrin core, the reactivity was strongly hindered most probably as a result of electronnegativity and coordination effect. While when nickel or coper ions were inserted, the reactivity was strongly accelerated as a result of decrease of electron density on the peripheral of porphyrin core.3. We have reported the synthesis of meso-fluoroporphyrin from easily available porphyrin synthons via SNAr reaction for the first time. meso-N02as well as halogen-substituted porphyrins (F, Cl, Br, I) could all be participated in this kind of transformation. The reactivities of different meso-substituted porphyrins reacting with phenols were measure and ranked in the order:F> Cl> NO2> Br> I. This characteristic is in consistence with typical addition-elimination mechanism of aromatic nucleophilic substitution reactions. Judging form these facts, we conclude this reaction most probably proceded through a typical addition-elimination mechanism or a Meisenheimer complex process.4. In this thesis,36new porphyrin monomers and3porphyrin dimers have been synthesized, whose structures were characterized by’HNMR,13C NMR as well as HR-MS unambigiously. We have also studied the UV-vis properties as well as fluorescent properties of these newly prepared porphyrins with different functional groups attatched on the meso-position and the results show the electron density on porphyrin core is strongly affected by these heteroatoms.更多还原