Light-Emitting Superstructures with Anion Effect: Coordination-Driven Self-Assembly of Pure Tetraphenylethylene Metallacycles and Metallacages
Light-Emitting Superstructures with Anion Effect: Coordination-Driven Self-Assembly of Pure Tetraphenylethylene Metallacycles and Metallacages
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DOI：
10.1021/jacs.6b00846
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发表时间：
2016-04-06
影响因子：
15
通讯作者：
Stang, Peter J.
中科院分区：
文献类型：
--
作者：
Yan, Xuzhou;Wang, Ming;Stang, Peter J.
在本论文中，我们描述了四苯基乙烯(TPE)二铂(II)受体的合成，并通过配位驱动自组装，构建了纯TPE基二维六方金属环和带有三种不同反离子的三维鼓状金属环。金属环具有交替的TPE给体和受体单元，这些单元沿外周排列12个侧苯环，为观察到的聚集诱导发射(AIE)行为提供了基础。金属环类似地由基于热塑性弹性体的积木构成，特别是两个施主和四个受主，导致八个自由旋转的苯环装饰棱柱核心。当在CH2Cl2溶液中加入正己烷时，这些笼子在稀溶液中的荧光增强，表明聚集诱导的增强发射(AIEE)。研究了反阴离子对组装物光物理性质的影响。在CH2Cl2中，含不同反阴离子的SCCs的摩尔吸收系数(Epsilon)、荧光发射强度和量子产率(Phi(F))的大小顺序为：PF6->；OTf->；NO3-。同样的趋势也适用于处于聚集状态的SCC的AIE特征。这里开发的金属-有机材料不仅丰富了新出现的自组装AIE金属环和笼子的库，这些金属环和笼子有望成为开启荧光传感器和先进光学器件的候选者，而且还提供了对结构因素如何影响AIE活性SCC的光物理的理解。
Herein, we describe the synthesis of tetraphenyl-ethylene (TPE)-based di-Pt(II) acceptors as shown by X-ray analysis, which are subsequently used to construct pure TPE-based 2D hexagonal metallacycles and 3D drumlike metallacages with three different counteranions via coordination-driven self-assembly. The metallacycles possess alternating TPE donor and acceptor units that arrange 12 pendant phenyl rings along the outer perimeter that provide the basis for the observed aggregation induced emission (AIE) behavior. The metallacages are similarly constructed from TPE-based building blocks, specifically two donors and four acceptors, resulting in eight freely rotating phenyl rings decorating the prismatic core. The fluorescence of these cages in dilute solution is intensified when hexane is added to CH2Cl2 solutions, indicative of aggregation-induced enhanced emission (AIEE). The influence of the counteranions on the photophysics of the assemblies was investigated. The molar absorption coefficients (epsilon), fluorescence emission intensities, and quantum yield (Phi(F)) values of the SCCs with different counteranions in CH2Cl2 follow the order PF6- > OTf- > NO3-. The same trend also applies to the AIE characteristics of the SCCs in the aggregated state. The metal-organic materials developed here not only enrich a newly emerging library of self-assembly AIE metallacycles and cages that are promising candidates for turn-on fluorescent sensors and advanced optical devices but also provide an understanding of how structural factors affect the photophysics of AIE-active SCCs.