Synthesis, characterization and investigation of homogeneous oxidation activities of peripherally tetra-substituted Co(II) and Fe(II) phthalocyanines: Oxidation of cyclohexene

•Synthesis and characterization of peripherally tetra-substituted cobalt and iron phthalocyanines.•Investigation of catalytic activity of cobalt and iron phthalocyanine in cyclohexene oxidation.•Determination of substrate, oxidant and temperature effect on cyclohexene oxidation.

The synthesis and characterization of novel peripherally tetra-substituted iron(II) 4 and cobalt(II) 5 phthalocyanines are described for the first time in this study. All the new compounds are characterized by a combination of IR, 1H and 13C NMR, mass and UV–vis spectroscopy techniques. Complexes 4 and 5 served as catalyst for the oxidation of cyclohexene using different types of oxidants, such as tert-butyl hydroperoxide (TBHP), m-chloroperoxybenzoic acid (m-CPBA), aerobic oxygen and hydrogen peroxide (H2O2). During the oxidation process the products formed are 2-cyclohexene-1-ol, 2-cyclohexene-1-one and cyclohexene oxide. The selectivity for 2-cyclohexene-1-ol is favored when iron(II) and cobalt(II) phthalocyanine catalysts are employed. The higher conversion is obtained as catalyst iron(II) phthalocyanine (96%). TBHP was determined as the successful oxidant with the minimum demolition of the catalyst, superior selectivity and conversion in the oxidation products.

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