PHOSPHORESCENCE SPECTRUM, VIBRONIC ANALYSIS, AND LATTICE FREQUENCIES OF NAPHTHALENE MOLECULE IN A DEUTERONAPHTHALENE CRYSTAL

The phosphorescence spectrum of naphthalene showing 94 transitions between 21 224 and 16 880 cm-1 has been obtained. These data help resolve uncertainties in the vibrational assignments, suggest the presence of localized lattice vibrations in isotopic mixed crystals, and may indicate the relative importance of singlettriplet coupling mechanisms in naphthalene and some halogenated naphthalene derivatives. The data have been used to identify the corresponding absorption and phosphorescence of the pure crystal and might be used in explaining temperature, environmental, and isotope effects on the radiative or radiationless transition probabilities of the naphthalene molecule.