The paper presents the results of studies conducted with the use of stationary and time-resolved fluorescence spectroscopy for the new derivative 2-Hydroxy-N-(2-phenylethyl)benzamide (SAL-3) in aqueous solutions with various concentrations of hydrogen ions as well as in solvent mixtures (i.e. media with changing polarity/polarizability). For the compound selected for the study placed in aqueous solutions with varying concentrations of hydrogen ions, the fluorescence emission spectra revealed a single emission band within most of the pH range, however, at low pH (pH<3 (esipt–excited (new (noticeable (protic) (related (with ) [td]dft–time-dependent a aforementioned analogues analyzed and as as, association band based be before between both broadening calculations carbonyl case change compound). conducted confirmed conformational density dipole dual effect effects effects.< excited experiments, facilitates fluorescence fluorescence) for forms functional group importantly, in interesting intramolecular ionic it literature) may molecule moment most necessary never non-ionic observed observed. of on p particular ph phenomena phenomenon polar positioning possibility possible presence presented previously proton published quantum-mechanical related reported shifting side significant solvents solvents, specific state substituent system). system, that the theory) the–oh this to transfer transfer) two unobserved varying very was water we well whereas, which with>