title: The effect of pH on the photophysics and photochemistry of disulphonated aluminum phthalocyanine
abstract: The results of a study of the effect of pH on the photophysics and photochemistry of di-sulphonated aluminum phthalocyanine (AlPcS2) in aqueous solution are presented. The pH dependence of the triplet quantum yield, fluorescence quantum yield, singlet-oxygen quantum yield, triplet lifetime, fluorescence lifetime and apparent dimerization constants is investigated and the results interpreted in terms of the pH dependence of the nature of the axial ligands. Evidence that the aluminum-axial ligand bond strength, rather than dimer binding energy that determines the extent of dimerization is provided by semi-empirical and ab initio calculations. Possible dimer structures obtained using ab initio calculations are discussed.
authors.affiliation: Department of Chemistry, Imperial College of Science, Technology and Medicine, London, UK. rbostler@ic.ac.uk
authors.initials: RB
authors.lastname: Ostler
authors.initials: AD
authors.lastname: Scully
authors.initials: AG
authors.lastname: Taylor
authors.initials: IR
authors.lastname: Gould
authors.initials: TA
authors.lastname: Smith
authors.initials: A
authors.lastname: Waite
authors.initials: D
authors.lastname: Phillips