Alkylcobalt(III) and alkylperoxocobalt(III) species of porphyrin and porphy
cene have been prepared and characterized by UV-vis and H-1 NMR spectroscop
ic measurements. Thermal decomposition of the alkylperoxocobalt species pro
ceeds via Co-O or O-O bond cleavage, which depends on the coordination of a
n axial ligand.