Electronic States of the Naphthalene Crystal

Abstract

The existing experimental data on the low‐temperature fluorescence and absorption of naphthalene crystal is reviewed and correlated with our own data. Some preliminary work on crystals of C₁₀D₈ is included. A vibrational analysis of the first moderately strong absorption region, 31 476—33 700 cm^—1 is made on the basis of the corresponding absorption of naphthalene in solid solution with durene. Some constants of the exciton theory of molecular crystals are obtained for the first and second excited singlet molecular states. Some discrepancies with the theory are pointed out; one of these is removed by calculating the crystal induced mixing of the two excited molecular states. Factor group splitting is found for certain vibronic levels of the ground and first excited state, but most vibronic levels of these states do not split appreciably.