Luminescent Alkylaluminium Anthranilates Reaching Unity Quantum Yield in the Condensed Phase

Transition, post-transition and rare earth metal complexes supported by (O,N)- and (N,N)-type ligands dominate organometallic photochemistry. However, despite a vast number of aminobenzoate metal complexes having been reported, and aluminium being globally abundant, alkylaluminium anthranilates have not yet been considered as effective luminophores. Herein, using a family of commercially available anthranilic acid (anth-H2) ligands and its N-substituted derivatives, we report the isolation and characterisation of a series of unique tetrameric chiral-at-metal alkylaluminium anthranilates, [(R´-anth)AlR]4. The resulting compounds are characterised using spectroscopic methods and single-crystal X-ray diffraction to analyze structure-determining factors in the solid state and solution. By then changing the N-substituents from H to Me and Ph, we have yielded a series of luminophores that exhibit poor-to-excellent performance, providing a [(Ph-anth)AlEt]4 derivative that achieves a unity photoluminescence quantum yield in the condensed phase, which is unprecedented for aluminium complexes.