Investigating the sensitization of the ytterbium(III) NIR emission by non-sandwich type Yb(III)-porphyrin coordination compounds

Abstract

Two porphyrin ligands with peripheral chelate groups linked at meso and β positions and their two new non-sandwich-type ytterbium(III)-porphyrin coordination compounds have been synthesized. New porphyrin compounds and the two coordination compounds were characterized by Nuclear Magnetic Resonance, High Resolution Mass Spectrum, Ultraviolet and visible, and fluorescence in the visible and Near Infrared (NIR) regions. The two Yb(III) complexes afforded the photoluminescence quantum yields of 2.0% and 1.6% for Yb(III) characteristic NIR emission in DMSO. Finally and importantly, the impact factors on the sensitization of Yb(III) NIR emission by porphyrin ligands via non-sandwich-type linkage were investigated by theoretical calculations and further measurements on fluorescent properties. It is proposed that the sensitization efficiency for the distance between the sensitizer and Yb(III) NIR emitter is better than that for conjugated degree of the peripheral porphyrin linkage.