Organometallic emitting dyes: Palladium(II) nile red complexes

The Nile Red dye, H(NR), forms cyclometalated R2-disubstituted-acetylacetonato square planar Pd(II) complexes (1–3; R = CH3, CF3, C6H5 respectively) whose photophysical properties were tested in cyclohexane, dichloromethane or methanol solutions. In cyclohexane 1–3 emit in the range 580–650 nm with a quantum yield ranging from 0.12 (R = CH3) to 0.50 (R = CF3) and lifetimes between 0.88 and 4.46 ns. These complexes form a new family of notably efficient red emitting organometallic dyes which could be of interest for practical applications.