Magnetic circularly polarized luminescence of zinc phthalocyanine in an argon matrix

The magnetic circularly polarized luminescence (MCPL) of the Q transition of zinc phthalocyanine has been measured in an argon matrix. These are the first such measurements for a matrix-isolated sample and support previous interpretations that require a crystal-field-stabilized Jahn-Teller splitting in the ¹E_u(π*) excited state. A moment analysis indicates the presence of a Ham effect which reduces the orbital angular momentum of this state by about 30%. Energy transfer between inequivalent sites in the matrix results in a red shift of the emission relative to the Q(0,0) absorption band.