Reaction of iron phthalocyanine with oxygen: Critical survey and new data on the structure of the forming PcFe(II) mu-oxo dimer

Reaction of iron tetra-4-tert-butylphthalocyanine ((PcFe)-Fe-t) with oxygen in noncoordinating solvents at (PcFe)-Fe-t concentrations within (0.63-10. 71) x 10(-2) M was studied. The uptake or oxygen (moles per mole of iron ph thalocyanine taken into reaction) depends on the concentration of the compl ex, varying in the examined concentration range from 1/5 to 1/2.7, and thus can significantly differ from the Value implied by the stoichiometry of th e (PcFe)-Fe-t mu -oxo dimer. This fact is due to consumption of the reactan ts in side processes, including, oxidative degradation of the macroring. In deed, the mu -oxo dimer is the major but not the only product of reaction o f (PcFe)-Fe-t with oxygen: Up to 20% of the initial complex undergoes oxida tive degradation. These data, in combination with the spectral and chemical properties or the (PcFe)-Fe-t mu -oxo dimer, suggest that this compound is an Fe(2+) derivative.