Mechanistic study of β-hydroxy elimination from [tetra sulphophthalocyanine CoIII-CR1R2CR3R4OH] in aqueous solutions. A pulse radiolysis study

Abstract

The reactions of cobalt(II) tetrasulphophthalocyanine, [Co^II(tspc)]^4– with ˙CH₃, ˙CH₂CH₂OH, ˙CH(CH₃)CH₂OH, ˙CH(CH₃)CH(CH₃)OH and ˙CH₂C(CH₃)₂OH free radicals have been studied. The results indicate that the first product formed in these reactions has the form [Co^II—(tspc—R)]^4–, where R is the aliphatic free radical, the exact nature of the bonding of ˙R to tspc is not clear. The complex [Co^II—(tspc—R)]^4– rearranges into [(tspc)Co^III—R]^4– in a process obeying a first-order rate law. [(tspc)Co^III—CH₃]^4– decomposes into [Co^III(tspc)]^3–+ CH₄, whereas the complexes [(tspc)Co^III—CR₁R₂CR₃R₄OH]^4– decompose into [Co^III(tspc)]^3–+ R₁R₂CCR₃R₄+ OH^–.