A dialkylsilicon porphyrin Si(TPP)(CH2CH3)(2) (1) (TPP 5 10, 15, 20-te
traphenylporphinato) reacted with dioxygen in the dark to give a bis(e
thylperoxide) complex (5), from which a dihydroxysilicon porphyrin (Si
(TPP)(OH)(2), 6) was obtained upon reduction and hydrolysis. In contra
st with the phosphorous analogue [P(TPP)(OH)(2)]OH, the crystal struct
ure of 6 showed an almost planar conformation of the porphyrin ligand.