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

© The Royal Society of Chemistry. Isomorphous ß-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 ß-diketonate complexes. Mixed lanthanoid complexes were also formed and their luminescence properties studied, with effective sensitisation of the 4F3/2 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

Photophysical investigation of near infrared emitting lanthanoid complexes incorporating tris(2-naphthoyl)methane as a new antenna ligand

© 2019 The Royal Society of Chemistry. A conjugated β-triketone, tris(2-naphthoyl)methane (tnmH), has been synthesized and successfully utilized as an antenna moiety for sensitization of the trivalent lanthanoids Eu 3+ , Sm 3+ , Yb 3+ and Nd 3+ , in an isomorphous series of mononuclear complexes formulated as [Ln(tnm) 3 (DMSO) 2 ] (Ln 3+ = Nd 3+ , Sm 3+ , Eu 3+ , Gd 3+ and Yb 3+ ). The photophysical properties of the materials were characterized as comprehensively as possible, with overall quantum yields, intrinsic quantum yields based on calculated radiative decays, and sensitization efficiencies reported. This investigation improves understanding of the sensitization processes occurring in the near-infrared (NIR) region, where quantitative data are currently scarce. In fact, the [Yb(tnm) 3 (DMSO) 2 ] and its deuterated analogue, [Yb(tnm) 3 (d 6 -DMSO) 2 ], present high values of overall quantum yield of 4% and 6%, respectively, which makes them useful and readily accessible references for future investigation of NIR-emitting systems