Hydrogenation of di(methoxo)tetraphenylporphyrin phosphorus(V) to isobacteriochlorin, chlorin, and phlorin complex with long-wavelength absorption band

We report the synthesis of nonmetal high-valent phosphorus(V) hydroporphyrin complexes: PV-isobacteriochlorin, PV-chlorin, and two isomers of PV-phlorin, via simple hydrogenation of di(methoxo)tetraphenylporphyrin phosphorus(V) with a hydrogen source and Pd/C catalyst. These PV-hydroporphyrin complexes exhibit long-wavelength absorption bands in the biological optical window. PV-isobacteriochlorin and PV-chlorin complexes are stable against auto-oxidation and exhibit the photoproduction of singlet oxygen under red light irradiation.