The effect of chromophore-chromophore interaction on the spectral luminescent properties of oxazine dye dimers

Spectral and luminescent properties were studied for chemical dimers and molecular aggregates of Nile Red oxazine dye in solutions. Chemical bonding of two oxazine dye molecules leads to the formation of a dimer whose spectral behavior is in close agreement with the exciton model constructed for “physical” molecular aggregates. Chemical dimers luminesce, whereas dimers formed because of van der Waals interactions do not.