PHOTOCHEMISTRY AND PHOTOPHYSICS OF ANTIMONY(III) HYPER PORPHYRINS - ACTIVATION OF DIOXYGEN INDUCED BY A REACTIVE SP EXCITED-STATE

Observations of the photoredox reactivity of antimony(III) porphyrin c omplexes are reported. Upon irradiation with visible light under ambie nt conditions, a photooxidation to the corresponding dihydroxoantimony (V) porphyrins occurs. At the same time a two-electron or four-electro n reduction of molecular oxygen takes place, depending on the experime ntal conditions. In the absence of suitable electron accepters, a phot oinduced disproportionation reaction occurs. The photolysis of antimon y(III) porphyrins shows a pronounced wavelength dependence. The reacti ve excited state is concluded to be of the metal-centered sp type. An extended model for the electronic structure of p-type hyper metallopor phyrins is suggested.