Dual emission caused by ring inversion isomerization of a 4-methyl-2-pyridyl-pyrimidine copper(I) complex.
Dual emission caused by ring inversion isomerization of a 4-methyl-2-pyridyl-pyrimidine copper(I) complex.
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DOI：
10.1021/ja103718e
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发表时间：
2010-06
影响因子：
15
通讯作者：
Michihiro Nishikawa;Kuniharu Nomoto;S. Kume;Keiichi Inoue;M. Sakai;M. Fujii;H. Nishihara
中科院分区：
文献类型：
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作者：
Michihiro Nishikawa;Kuniharu Nomoto;S. Kume;Keiichi Inoue;M. Sakai;M. Fujii;H. Nishihara
以2-吡啶基-4-甲基嘧啶和双膦为配体，合成了一种新的可转化的铜配合物。该配合物具有基于嘧啶环的反转运动的机械双稳态，从而导致双重发光行为。反转动力学强烈依赖于温度和溶剂。变温（1）H NMR谱表明，两种异构体在溶液中通过环反转发生相互转化，且在200 K以下运动被冻结。配合物在溶液中具有特征的CT吸收和发射带。发射寿命的测量表明，发射可以去卷积成两个组件。快组分和慢组分归属于两种异构体，其激发态的特征在于不同的结构弛豫过程和/或额外的溶剂配位性质。这两种异构体的发射性质不仅在寿命和波长上不同，而且在热敏性上也不同。通过与抗衡阴离子的静电相互作用，两种异构体的摩尔比随溶剂的极性而变化。转化率受溶剂的影响，表明溶剂配位促进了转化。
We developed a new convertible copper(I) complex using 2-pyridyl-4-methylpyrimidine and diphosphine as ligands. This complex exhibited mechanical bistability based on the inversion motion of the pyrimidine ring, leading to dual luminescence behavior. The inversion dynamics was strongly dependent on temperature and solvent. Variable-temperature (1)H NMR spectra revealed that the two isomers interconverted in solution via ring inversion, and the motion was frozen below 200 K. The complex exhibited characteristic CT absorption and emission bands in solution. Emission lifetime measurements demonstrated that the emission could be deconvoluted into two components. The fast and slow components were assigned to the two isomers, the excited states of which were characterized by different structural relaxation process and/or additional solvent coordination properties. The emission properties of the two isomers differed not only in lifetime and wavelength but also in heat sensitivity. The molar ratio of the two isomers varied with the polarity of the solvent via electrostatic interactions with the counteranion. The rate of inversion was affected by solvent, suggesting that inversion was promoted by solvent coordination.