Synthesis, optical absorption and photophysical properties of cone-shaped subnaphthalocyanine

The first photophysical studies of a member of the family of subnaphthalocy anines are described. The cone-shaped unsubstituted subnaphthalocyanine, sy nthesized in 35% yield, provides it with distinctive photophysical properti es that are better than those of the related planar phthalo- and naphthaloc yanines. SubNc absorbs in the red part of the spectrum, has substantial flu orescence, Phi(F)=0.22, and, significantly for photodynamic therapy applica tions, triplet and singlet oxygen quantum yields, Phi(T)=Phi(Delta)=0.68, t hat are substantially higher than those of the related phthalo- and naphtha locyanines. These results, together with their synthetic availability, high solubility, and low tendency to aggregate, make this new class of sensitis ers amenable to being further studied with a view to finding photodynamic t herapy applications.