Fluorescent dyes as efficient photosensitizers for near-infrared Nd3+ emission

A series of six dye-functionalized Nd3+ complexes have been synthesized and their photophysical properties have been studied and evaluated. The incorporated dyes dansyl, coumarine, lissamine, and Texas Red possess broad and intense absorption bands in the visible spectral region and therefore are ideally suitable as photosensitizers for near-infrared Nd3+ luminescence, despite their very low intrinsic intersystem crossing quantum yields. The Nd3+ complexes display sensitized near-infrared luminescence upon excitation of the dyes. The enhancement of the intersystem crossing quantum yield of the dyes by the complexed Nd3+ ions plays a crucial role in the sensitization process.