Experimental and theoretical study of three newly-synthesized iminochalcones: An example of dual emission induced by polarity changes

•Iminochalcones with different substituents were synthesized and characterized.•Spectral properties of these compounds are highly sensitive to solvent polarity.•Dual fluorescence due to change in polarity is found for one of the compounds.•DFT calculations confirm the energies of the LE and ICT polar emissive states.