On the Multiplicity of the Phosphorescent State of Organic Molecules

Abstract

The value of the ``multiplicity'' gu for use in the equation kp=2πcν2n2(gl/gu) ∫ εdν̄ is discussed and shown to lie in the range 1 ≤gu≤∞. The value best suited to most organic compounds at 77°K is shown to be gu=3. The number of emitting triplet components is shown to be readily derivable for large classes of compounds and to correlate with experiment. The effects of magnetic-field strength on triplet component energies, on phosphorescence lifetime, on phosphorescence polarization, and on gu are calculated and shown to produce large effects in the specific case of naphthalene-d8.