Zhang Lu-Yin, Hou Ya-Jun, Pan Mei, Chen Ling, Zhu Yi-Xuan, Yin Shao-Yun, Shao Guang, Su Cheng-Yong
MOE Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
Dalton Trans. 2015 Sep 14;44(34):15212-9. doi: 10.1039/c5dt00545k.
Four Ru(II)/Ir(III) metalloligands have been designed and synthesized from polypyridine and bibenzimidazole (BiBzIm) organic ligands, which show strong visible light absorption via metal-to-ligand charge transfer (MLCT) transitions. Nd/Yb(III) complexes were further assembled from these Ru(II)/Ir(III) metalloligands, and Ln(III)-centered NIR emissions can be efficiently sensitized by (3)MLCT states of the metalloligands in the visible-light region. The energy transfer rates for the complexes are generally in the order Nd > Yb, which is due to the better matching between (3)MLCT states of Ru(II)/Ir(III) metalloligands and densely distributed excited states of Nd(III) ions. Long decayed lifetimes on a μs scale and high quantum yields up to 1% are obtained in these lanthanide complexes, suggesting that the Ru(II)/Ir(III) metalloligands can serve as a good visible light harvesting antenna to efficiently sensitize Ln(III)-based NIR luminescence.
已从多吡啶和联苯并咪唑（BiBzIm）有机配体设计并合成了四种Ru（II）/Ir（III）金属配体，它们通过金属到配体的电荷转移（MLCT）跃迁表现出强烈的可见光吸收。Nd/Yb（III）配合物由这些Ru（II）/Ir（III）金属配体进一步组装而成，并且在可见光区域中，金属配体的（3）MLCT态可以有效地敏化以Ln（III）为中心的近红外发射。配合物的能量转移速率通常按Nd>Yb的顺序排列，这是由于Ru（II）/Ir（III）金属配体的（3）MLCT态与Nd（III）离子密集分布的激发态之间更好的匹配。在这些镧系配合物中获得了微秒级的长衰减寿命和高达1%的高量子产率，这表明Ru（II）/Ir（III）金属配体可以作为良好的可见光捕获天线，有效地敏化基于Ln（III）的近红外发光。
