Transient absorption studies of indium phthalocyanines

Summary form only given. In this work the variation of the photophysics of substituted indium phthalocyanines (Pc) with axial substituent is examined. The two materials examined, ClInPc(/spl beta/-t-Bu)/sub 4/ and IInPc(/spl beta/-t-Bu)/sub 4/, are known to have large nonlinear absorption coefficients arising from a strong triplet-triplet absorption in the lowest excited state. The object is to determine if the rate of formation of the triplet state, i.e. the intersystem crossing rate, can be enhanced by introducing iodine at the axial position.