Simultaneous modification of N-alkyl chains on cyclometalated and ancillary ligands of cationic iridium(III) complexes towards efficient piezochromic luminescence properties
Simultaneous modification of N-alkyl chains on cyclometalated and ancillary ligands of cationic iridium(III) complexes towards efficient piezochromic luminescence properties
复制标题
同时修饰阳离子铱（III）配合物的环金属化和辅助配体上的N-烷基链以获得有效的压致变色发光性能
DOI：
10.1039/c4tc02879a
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发表时间：
2015-01-01
影响因子：
6.4
通讯作者：
Liao, Yi
中科院分区：
文献类型：
--
作者：
Han, Yi;Cao, Hong-Tao;Liao, Yi
在本研究中，我们设计并合成了一系列具有不同长度N-烷基的2-苯基-1H-苯并咪唑环化配体和苯基吡啶型辅助配体的多功能阳离子铱（III）配合物。每个配合物的物理性质进行了详细的研究，也确定了全面的密度泛函理论计算。尽管在溶液中对它们的发射光谱和激发态特性的影响可以忽略不计，但改变N-烷基链的长度可以有效地改变它们在固态下的物理化学性质。所有配合物都表现出迷人的可见压致发光（PCL）行为。最有趣的是，这些具有较长N-烷基链的铱（III）基发光体通过机械研磨和溶剂发烟显示出显着的发射颜色变化和独特的可逆特征。粉末X射线衍射（PXRD）、H-1 NMR和MALDI-TOF/TOF质谱数据表明，晶态和非晶态之间的相变是该压色性的关键。此外，由于聚集态的高量子效率，所研究的铱（III）配合物可以作为一个有效的传感器的敏感性和选择性检测的爆炸物，2，4，6-三硝基苯酚（TNP）。
In this study, we have designed and synthesized a series of multifunctional cationic iridium(III) complexes with different lengths of N-alkyl chains on 2-phenyl-1H-benzimidazole-based cyclometalated ligands and phenyl-pyridine type ancillary ligands. The photophysical properties of each complex have been investigated in detail and also ascertained by comprehensive density functional theory calculations. Despite showing negligible influence on their emission spectra and excited-state characteristics in solution, altering the N-alkyl chain length can efficiently modify their photophysical properties in the solid state. All complexes exhibit fascinating visible piezochromic luminescence (PCL) behaviour. Most interestingly, these iridium(III)-based luminophores with longer N-alkyl chains display significant emission colour changes and unique reversible features by mechanical grinding and solvent fuming. The powder X-ray diffraction (PXRD), H-1 NMR and MALDI-TOF/TOF mass spectrometry data demonstrate that the phase transitions between crystalline and amorphous states are crucial to the present piezochromism. Moreover, with the merit of high quantum efficiency in aggregate states, the studied iridium(III) complex can serve as an efficient sensor for the sensitive and selective detection of the explosive, 2,4,6-trinitrophenol (TNP).