Preparation and Spectroscopic and Electrochemical Characterization of Trivalent Manganese and Iron Chelates of 5,14-Dihydro-7,16-diethyl-(E)-or-(Z)-dipyrido[b,i][1,4,8,11]tetraazacyclotetradecine

Abstract

The reaction of the manganese(II) or iron(II) salt with 5,14-dihydro-7,16-diethyl-(E)-or-(Z)-dipyrido[b,i][1,4,8,1] tetraazacyclotetradecine yielded the corresponding manganese (III) or iron (III) complex of a 1:1 molar ratio of ligand to metal with an anion in the axial position as the fifth ligand. The spectral properties and redox characteristics of these complexes were reported. The mass spectra all showed parent peaks. A strong IR band dependent on the C≡N stretching mode was observed at ca. 2045 cm¹ for the isothiocyanatomanganese (III) complexes, which are N-bonded. Judging from analogy with the cyclic voltammograms of M(1-Z)X and M(1-E)X, the delocalization of a conjugated system at each complex is approximately equivalent.