Emission spectra studies on the hydrogen-bonding complexes between p-methoxy-2-styrylquinoline and acids

The ground and excited state interactions between p-methoxy-2-styrylquinoline (2-StQ-OMe) and different protic acids with various acid concentrations were studied in different media. Emission bands due to the hydrogen bonding complex, protonation complex and aggregation or solid complex were observed for the first time, in n-hexane. The different reaction pathways were controlled by the solvent polarity and the concentrations of the protic acid. The acidity of acid was also important to the acid-base complex.