A luminescent quadruple stranded dinuclear Eu(III) complex based on 2,8-bis(4′,4′,4′-trifluoro-1′,3′-dioxobutyl)-dibenzothiophene for light-emitting diodes

A luminescent quadruple stranded dinuclear Eu(III) complex Na2[Eu2(dbt)4] was synthesized, where H2dbt was 2,8-bis(4′,4′,4′-trifluoro-1′,3′-dioxobutyl)-dibenzothiophene. The complex emits the characteristic red luminescence of Eu3+ ion due to the 5D0 → 7FJ (J = 0–4) transitions under 395 nm-light excitation with a luminescent quantum efficiency of 23%. Bright red light-emitting diodes (LEDs) were fabricated by coating the complex onto 395 nm-emitting InGaN chip. The results indicate that the complex may act as a red component in the fabrication of near UV-based white light-emitting diodes with high color-rendering index.