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

Isomorphous -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 -diketonate complexes. Mixed lanthanoid complexes were also formed and their luminescence properties studied, with effective sensitisation of the F-4(3/2) of Nd(3+)via the D-5(0) 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.