THE PREPARATION AND PHOTOPHYSICAL MEASUREMENTS OF PERDEUTERO ZINC PHTHALOCYANINE

The fully deuterated photosensitizer, zinc phthalocyanine-d(16), was synthesized and its excited singlet and tripler state photophysics determined. Surprisingly, no differences in the excited state kinetics or quantum yields were observed compared with the undeuterated material. Furthermore, deuteration of the axial pyridine ligand of the metallophthalocyanine produced no changes in its photophysical behaviour. These results are compared with recent work (A. Beeby, A.W. Parker, M.S.C. Simpson and D. Phillips, J. Photochem. Photobiol. B: Biol, 16 (1992) 73-81) in which the photophysical properties of aluminium phthalocyanines were altered in deuterated solvents, and the effects of deuteration on the non-radiative relaxation processes of phthalocyanines were discussed. Implications for the use of such compounds in photodynamic therapy are also mentioned.