SYNTHESIS, SPECTROSCOPIC AND ELECTROCHEMICAL PROPERTIES OF TETRAZOLATOMANGANESE(III) PORPHYRINS

摘要

The synthesis, spectroscopic characterization and electrochemical properties of four tetrazolatomanganese(III) porphyrins are reported. The investigated compounds are represented by (TPP)Mn[N4C(R)], where TPP is the dianion of tetraphenylporphyrin and R is CH2CH3, C6H5, CH=CH2 or CH=CHCN. Each complex was characterized by IR, UV-vis and H-1 NMR spectroscopy, as well as by mass spectrometry. Variable-temperature H-1 NMR data demonstrate that the electron-withdrawing effect of the tetrazolato ligand in (TPP)Mn[N4C(R)] is higher than that of the azido axial ligand in (TPP)MnN3. The reductions of each sigma-bonded (TPP)Mn[N4C(R)] derivative were also examined in four non-aqueous solvents (dichloromethane, benzonitrile, tetrahydrofuran and pyridine) and the resulting data compared with data in the literature for manganese(III) porphyrins containing an ionic axial ligand such as Cl- or ClO4-. [References: 32]