Spectroscopic investigations of intramolecular and intermolecular excimers of 1,3-di(2-naphthyl) propane and methylnaphthalenes in supercritical carbon dioxide

Intramolecular excimer formation in 1,3-di(2-naphthyl)propane was studied spectroscopically in room-temperature solutions and in supercritical CO2. The results were compared with those of intermolecular excimer formation in l-methylnaphthalene and 2-methylnaphthalene under the same experimental conditions. The implication of the results to the concept of local concentration augmentation as a mechanism for the solute-solute clustering in supercritical fluids is discussed along with the known results of enhanced pyrene intermolecular excimer formation in supercritical CO2 under near-critical conditions.