Energy transfer between Eu3+ and Nd3+ in near-infrared emitting β-triketonate coordination polymers

Abstract

Isomorphous β-triketonate-based lanthanoid polymers containing tris(4-methylbenzoyl)methanide (mtbm) and Rb⁺ with formula {[Ln(Rb)(mtbm)₄]₂}_n (Ln = Eu³⁺ and Nd³⁺) have been synthesised and structurally characterised. The photophysical properties for the Nd³⁺ complex presented relatively long lifetimes and high quantum yields in comparison with analogous β-diketonate complexes. Mixed lanthanoid complexes were also formed and their luminescence properties studied, with effective sensitisation of the ⁴F_3/2 of Nd³⁺via the ⁵D₀ of Eu³⁺, which is to the best of our knowledge the first example of Eu³⁺ to Nd³⁺ sensitisation in a structurally defined coordination complex or polymer.