Influence of the Type of Macrocycle on the Stabilisation of the High Oxidation State of the Manganese Ion and Electrode Processes.

Dinuclear di--oxo complexes of Mn and Mn ions, and mononuclear complexes of Mn ions with tetraazamacrocycles ([12]aneN, [14]aneN, [15]aneN) and -substituted derivative (Me[14]aneN) as well as mononuclear complexes of Mn ions with -substituted derivatives ((-Me)[14]aneN, (-Me)[14]aneN, (-Me)Mepy [14]aneN) and with oxo[14]aneN were studied. Based on spectroscopic (UV VIS and IR) and conductometric studies, the types of synthesised complexes ( or isomers of mononuclear Mn complexes, oxygen bridges and class II according to Robin and Day classification for dinuclear complexes) were determined. On the basis of voltammetric and spectroelectrochemical studies, isomerisation at the level of Mn ion complexes and isomerisation at the level of Mn ion complexes were demonstrated for complexes of ligands with free C positions. The -substituted derivatives oxidise according to the EC mechanism, in which the follow-up reaction is a disproportionation reaction. The thermodynamic stabilisation of Mn ions was determined by comparing the formal potentials (), the disproportionation constants () and the formation constants (). The study showed the possibility of oxidation of mononuclear, pseudo-octahedral Mn ion complexes to dinuclear complexes and the greatest stabilisation of Mn ions, both in monomers and dimers of ligands with free positions.