ON THE AGGREGATIVE PROPERTIES OF RHODAMINE 6G IN ETHANOLIC SOLUTIONS

A new experimental technique has been developed whereby the observation of the absorption bands due to the tetrameric species of rhodamine 6G in ethanolic solutions could become possible for the first time. The excitonic treatment of the electronic data backed by the H-1 NMR and vibrational studies suggest a coplanar structure for the dimers whereas the interaction between the parallel planes at a twisted angle of THETA = 108-degrees can constitute the tetrameric aggregates. The nature of the transitions involved in the absorption spectra are shown to be vibronic. The symmetry considerations have therefore been taken into account in order to ascertain the validity of the proposed structure for the tetramers.