Probing the effect of β-triketonates in visible and NIR emitting lanthanoid complexes

Abstract

An isomorphous series of lanthanoid complexes containing tribenzoylmethanide ( tbm ) and 1,10-phenanthroline ( phen ) ligands has been synthesised and structurally characterised. These complexes, formulated as [Ln( phen )( tbm )3] (Ln = Eu3+, Er3+ and Yb3+), were compared with analogous dibenzoylmethanide ( dbm ) [Ln( phen )( dbm )3] complexes to investigate the effect of changing β-diketonate to β-triketonate ligands on the photophysical properties of the complex. The photophysical properties for the Eu3+ complexes were similar for both systems, whereas a modest enhancement was observed for Yb3+ and Er3+ moving from the dbm to the tbm complexes. A detailed study of the NIR photophysical properites was achieved by adapting the integrating sphere method for the calculation of overal quantum yields in the solid state.