Supramolecular luminescent system based on 2-cyano-3(4-(diphenylamino)phenyl) acrylic acid: Chiral luminescent host for selective CH3CN sensor

Abstract

New supramolecular luminescent host systems based on 2-cyano-3(4-(diphenylamino)phenyl) acrylic acid (CDPA), a triphenylamine based luminescent acid, and amines (propylamine (1), dimethylaminopyridine, DMAP (2) and (1S,2R)-2-amino-1,2-diphenylethanol (3)) were prepared using a supramolecular approach. For each, the inclusion of amines in the CDPA matrix led to blue shifts in the solid state luminescence. 1 forms a CH₃CN-selective, luminescent host and exhibits solvent dependent luminescent changes in the solid state. Crystallisation of CDPA-DMAP from EtOAc (2a) and CH₃CN (2b) produces two different solid forms which exhibit slight differences in luminescence (λ_max at 522 nm and 529 nm, respectively). The chiral luminescent host system (3a) obtained from CH₃CN shows robust, reversible CH₃CN-selective luminescent sensing (λ_max at 523 nm (with CH₃CN) and 553 nm (without CH₃CN)). In this case the luminescence changes with the crystallising solvent (MeOH (3b) and EtOH (3c)).