One trinucleus dimethine cyanine dye: Experimental and theoretical studies on molecular structure as well as absorption and fluorescence properties

► A kind of trinucleus dimethine cyanine dye 1 was synthesized and characterized. ► The structure of dye 1 was experimentally and theoretically studied. ► The electronic emission spectra were predicted in four different solvents with CIS/PCM. ► The simulated fluorescence spectra duplicated the experimental one for each solvent.