Femtosecond degenerate pump-probe spectroscopy was carried out on thin films of a series of axially substituted phthalocyanines including tBu(4)PcInCl(tBu(4) = tetra-(tert-butyl)), tBu(4)PcTiO, tBu(4)PcIn(p-TMP) [p-TMP = p-trifluoromethylphenyl], tBu(4)PCGa(p-CPO) [p-CPO = p-chlorophenoxy], and mu-oxo-bridged phthalocyanine dimers, e.g., [tBu(4)PcIn](2)O, tBu(4)PCIn-O-GaPctBu(4) and [tBu(4)PcGa](2)O. We demonstrate that the long lived state of the dynamics is the triplet state and the behavior of the degenerate pump-probe was determined by exciton-exciton annihilation (E-EA), nonradiative recombination (NR) and intersystem crossing (ISC) processes. The E-EA process is via. the long-range dipole-dipole interaction between excitons or motion-limited diffuse other than exciton hopping migrations. The dimers shows much efficient E-EA and the indium-contained samples have larger ISC rate than the others. (C) 2004 Elsevier B.V. All rights reserved.