Electrochemical, spectrochemical and catalytical properties of cobalt(II) phthalocyanine regioisomers studies
Joanna Szymczak, Tomasz Rębiś, Jadwiga Mielcarek, Michał Kryjewski
Abstract
Two regioisomers of tetrasubstituted cobalt(II) phthalocyanine bearing L-menthol moieties in the periphery, were synthesized through remetallation reaction of metal-free phthalocyanines as substrates. Mass spectrometry and UV-Vis spectrophotometry were employed for characteristics. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) studies indicate three one-electron ring-based oxidation processes, oxidation/reduction of cobalt center (Co(II)/Co(I)) and one ring-based reduction. The comparative studies of catalytic activity of the two phthalocyanines were investigated. Cyclohexene oxidation using tert-butylhydroperoxide (TBHP) and cobalt(II) phthalocyanines results in formation of 2-cyclohexen-1-one, 2-cyclohexen-1-ol, cyclohexanol, cyclohexene epoxide. Formation of 2-cyclohexen-1-one were favored.