Tuning Emission Properties via Aromatic Guest Inclusion in Organic Salts Composed of 4,4′-Dinitro-2,2′,6,6′-tetracarboxybiphenyl and Acridine

An organic salt composed of 4,4′-dinitro-2,2′,6,6′-tetracarboxybiphenyl and acridine has been shown to act as host to accommodate large polyaromatic guest molecules. Carboxylate–pyridinium hydrogen bonds, π–π and cation···π interactions are found to play a pivotal role in these host–guest complexes. All the complexes are found to exhibit distinct colors and photoluminescence which correlate with the charge-transfer interactions between acridinium ion and guest molecules, and ionization potential or donor ability of the guest molecules.