Single-component Eu3+–Tb3+–Gd3+-grafted polymer with ultra-high color rendering index white-light emission

Abstract

Through an approach of pre-coordination and following terpolymerization from vinyl-functionalized complex monomers [Ln(TTA)₃(4-VB-PBI)] (Ln = Eu, 2; Ln = Tb, 3 and Ln = Gd, 4; HTTA = 2-thenoyltrifluoroacetonate; 4-VB-PBI = 1-(4-vinylbenzyl)-2-(pyridin-2-yl)-1H-benzo[d]imidazole) with methyl methacrylate, the first example of a single-component Eu²⁺–Tb³⁺–Gd³⁺-grafted polymer Poly(MMA-co-2-co-3-co-4) was obtained. Moreover, control of an optimal dye content for suppressing Tb³⁺ to Eu³⁺ energy transfer and exciton formation provides new perspectives for hetero-Ln³⁺-grafted polymers as featured in Poly(MMA-co-2-co-3-co-4) with color-tuning to direct white-light (Commission International De L'Eclairage coordinates of x = 0.322, y = 0.331; corrected color temperature of 5979 K; and color rendering index up to 94), including a highly luminous efficiency of 17.8%.