Thermally activated delayed fluorescent (TADF) coordination polymer with the generation of singlet oxygen

4,4′-{9,9′-Spirobi[10 H -acridine]-10,10′-diyl}dibenzoic acid ( L , C 29 H 26 N 2 O 4 ) was designed and synthesized as a new donor–acceptor motif molecule. Due to the large dihedral angle between the planes of the carboxyphenyl group and the spiroacridine moiety, L possess thermally activated delayed fluorescence (TADF). By applying L as a ligand and using Cd as a metal connector, we synthesized the coordination polymer catena -poly[hemi-μ-aqua-aqua(μ 3 -4,4′-{9,9′-spirobi[10 H -acridine]-10,10′-diyl}dibenzoato)cadmium(II)], [Cd(C 29 H 24 N 2 O 4 )(H 2 O) 1.5 ] n , ( I ). X-ray crystallographic analysis revealed that this coordination polymer exhibits one-dimensional chains constructed from molecular twist-ring moieties, with Cd 2 O 11 clusters as the connection nodes. The stacking pattern of the two-dimensional network was formed by C—H...π interactions in the solid state. Similar to L , ( I ) presents a sky-blue TADF emission, together with a photoluminescence quantum yield (PLQY) of 40%. It is worth noting that the photocatalytic activity toward the generation of singlet oxygen of this coordination polymer is confirmed.