Heteroleptic heterometallic N-bridged porphyrinoids: The effects of macrocycle and metal on oxidation reaction

Abstract

Heteroleptic heterobimetallic mu -nitrido porphyrinoids MnPor-N-FePc and MnPc-N-FePor were prepared by using Mn-N3 porphyrinoid with corresponding iron porphyrinoid derivative and characterized by FT-IR, HRMS, MALDI-MS, UV-vis, EPR and Raman spectroscopic techniques. The characteristic Mn-N-Fe bands of both heteroleptic heterobimetallic mu -nitrido complexes were clearly confirmed by FT-IR and Raman spectroscopies. These two novel complexes were tested in oxidation of 2,3,5-trimethylphenol to 2,3,5-trimethyl-1,4-benzoquinone. Interestingly, the heteroleptic heterobimetallic mu -nitrido porphyrinoid MnPor-N-FePc was more efficient catalyst than MnPc-N-FePor. Computational studies explain that the different catalytic efficiency between MnPor-N-FePc and MnPc-N-FePor depends on the thermodynamic stability of the intermediates of both complexes on oxidation reaction. The intermediates of MnPor-N-FePc have better thermodynamic stability than MnPc-N-FePor.