Double fluorescence lifetimes of metal-free phthalocyanine in a mixed-solvent Shpol'skii matrix at 4·2 K

Abstract
We report identical double fluorescence lifetimes of τ = 3·7 and 6·3 ns for the 0-0 fluorescences of each of the two tautomeric species of metal-free phthalocyanine (H2Pc) in a mixed solvent matrix of α-chloronaphthalene and n-octane at 4·2K. Such double lifetime feature has not been reported previously for this molecule nor, to our knowledge, for any of the related phthalocyanines and porphyrins.