光致变色型金属—有机框架材料的合成与性能调控

发布时间：2018-05-08 13:09

本文选题：金属-有机框架 + 光致变色　；参考：《福建师范大学》2016年硕士论文

【摘要】：光致变色材料以其在光照后能够发生颜色变色这一特性,在光学存储器、生物荧光探测、分子开关、军事隐蔽伪装以及光学防伪识别等方面都有着广泛的应用。目前这类材料的研究主要集中在有机-无机杂化类材料和一些非孔特征的配位聚合物。它们的主体结构往往会随着模板剂的变化而改变,难以灵活地从结构上对光致变色行为和性能进行调控。金属-有机框架材料(MOFs)作为一类具有广泛应用前景的配位聚合物,其优异的结构可设计性和性能可调特征使其在最近二十年受到了广泛关注。本文选择微孔MOFs为研究对象,将光致变色紫精类小分子封装入微孔MOFs,通过改变不同的主体框架和引入不同的紫精分子,调控不同的主客体间相互作用,设计合成了4例具有光致变色行为的MOFs材料。首先,以甲基紫精阳离子(MV2+)作为客体分子,用不同的有机酸(均苯三甲酸,BTC或联苯二甲酸,BPDC)与铟离子构建了两例不同的阴离子MOFs主体框架,[In6(BTC)8]·(MV)3(1)和[In(BPDC)2]2·(MV)·4DMF (2),2中BPDC与MV2+之间存在明显的π-π相互作用,较好地稳定了光生MV+-自由基,观察到可逆的光致变色行为；而1中由于缺乏主客体相互作用,变色行为不可逆,变色主要起因于光生MV+自由基的生成,同时伴随着MV上C-N键的断裂。与此同时,还初步探讨了自由基对气体吸附性能的影响。其次,对于同一主体框架,我们合成和引入不同的紫精类阳离子,乙基紫精(EV)和苄基紫精(BzV),获得[In6(BTC)8]·(EV)3(3)和[In6(BTC)8]·(BzV)3(4)。3具有和1类似的光致变色行为,但是化合物4在室温下能够对紫外(3650 A)、软X射线(Cu-Ka,1.5418 A)和硬X射线(Mo-Ka,0.71073 A)三种光均有不同的、可逆的颜色响应,具有罕见的室温下肉眼区分软/硬X射线的功能。由于单晶数据中的苄基紫精被主体框架屏蔽,难以解析,初步推断大的苄基紫精的引入,赋予化合物4苄基和主体框架之间的相互作用,导致4具有有趣的多波长相关的光致变色现象。此外,我们还利用1,4,5,8-萘四甲酸酐与5-氨基四氮唑合成的配体构筑了一个结构新颖的二维萘二酰亚胺基光致变色MOFs材料[Zn(DTz-NDI)·(DMF)2] (5),发现化合物5的光致变色行为对其荧光性质有一定的调控作用。基于微孔MOFs的结构特征和构筑原理,本论文为光致变色材料的合成提供了一种设计灵活、结构可控、变色性能可调的新策略。
[Abstract]:Photochromic materials have been widely used in optical storage, biological fluorescence detection, molecular switch, military camouflage and optical anti-counterfeiting recognition due to their ability to change color after illumination. At present, the research of these materials is mainly focused on organic-inorganic hybrid materials and some non-porous coordination polymers. Their main structure often changes with the change of template, so it is difficult to adjust the photochromic behavior and performance flexibly. As a kind of coordination polymers with wide application prospects, metal-organic frame materials (MOFs) have attracted wide attention in the last two decades due to their excellent structural design and adjustable properties. In this paper, we choose microporous MOFs as the research object, encapsulate the small molecules of photochromic purple essence into the micropore MOFs, and regulate the interaction between host and guest by changing different host frame and introducing different purple molecules. Four MOFs materials with photochromic behavior were designed and synthesized. First of all, methyl violet cationic MV2) was used as the guest molecule. Two different anionic MOFs main frames were constructed by using different organic acids (BTC or BPDC) with indium ions. The interaction between BPDC and MV2 in [In6(BTC)8] MV ~ (3 +) and [In(BPDC)2] ~ (2) MV ~ (2 +) 4DMF ~ (2 +) was observed, and the photogenerated MV-free radical was well stabilized. The reversible photochromic behavior was observed, while in the absence of host-guest interaction, the chromotropic behavior was irreversible, which was mainly due to the formation of photogenic MV radical and accompanied by the breakage of C-N bond in MV. At the same time, the effect of free radicals on gas adsorption was also discussed. Secondly, for the same main frame, we synthesize and introduce different virulent cations, ethylViolin (EV) and benzyl Violet (BZV), and obtain [In6(BTC)8] EV3 (3) and [In6(BTC)8] BZV3 (4.3) with photochromic behavior similar to that of 1. However, compound 4 has different and reversible color responses to three kinds of light at room temperature, I. e., UV 3650 A, soft X ray Cu Kaf 1.5418A) and hard X ray Mo-Mo 0. 71073 A), and has the function of distinguishing soft and hard X-rays by naked eye at rare room temperature. Because the benzyl violet in the single crystal data is shielded by the main frame, it is difficult to analyze, so it is preliminarily inferred that the introduction of the large benzyl violet gives the interaction between the compound 4 benzyl and the main frame. Leading to 4 interesting multi-wavelength related photochromic phenomena. In addition, We have also constructed a novel two-dimensional naphthalenediamine photochromic MOFs material [ZnN DTz-NDI] DMF _ (2) O _ (5) by using the ligands synthesized with 5-aminotetramethanoic anhydride and 5-aminotetramethanoic anhydride. It is found that the photochromic behavior of compound 5 is related to its fluorescence properties. A certain regulatory role. Based on the structure characteristics and construction principle of microporous MOFs, this paper provides a new strategy for the synthesis of photochromic materials with flexible design, controllable structure and adjustable discoloration performance.
【学位授予单位】：福建师范大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：O641.4

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