The electronic states of the acridine orange fluorescent dye molecule in cationic (protonated) and neutral forms in an aqueous solution were studied by the time-dependence density functional theory. Transitions between these states corresponding to absorption of dye molecules in the visible region of the spectrum are investigated. The dipole moments of the ground and excited states are calculated and analyzed from the point of view of the theory of solvatochromism.
acridine orange, time-dependence density functional theory, polarizable continuum model, electronic transitions, molecular orbitals, solvatochromism
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