Zhang Liming, Li Bin, Su Zhongmin
Key Laboratory of Excited State Processes, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, PR China.
Langmuir. 2009 Feb 17;25(4):2068-74. doi: 10.1021/la803822s.
In this article, we report a phosphorescence enhancement phenomenon of [Cu(N-N)(P-P)]BF4 complexes in the solid state. The phosphorescence enhancement phenomenon is composed of three features: (1) an obvious emission blue shift, (2) a greatly enhanced photoluminescence quantum yield, and (3) a longer excited-state lifetime. Systematic analyses prove that the main cause of this phenomenon is nonradiative process suppression triggered by the pi stacking between [Cu(N-N)(P-P)]BF4 molecules. The phosphorescence enhancement widely exists in [Cu(N-N)(P-P)]BF4 complexes because of the pi surfaces in their diimine ligands.
