An unexpected dinuclear Mn(II,III) complex of an asymmetric macrocyclic ligand with a mono-arm

The template reaction of sodium 2,6-diformyl-4-methylphenolate (sdmp) and [N,N-bis(2-aminoethyl)]aminoacetic acid (baaa) subsequently transmetalled with Mn(II)(ClO4)2·6H2O has resulted in the generation of a dinuclear mixed-valence Mn(II)Mn(III) complex of a tetraimine macrocyclic Schiff base with a single carboxylic arm, in which unusual group elimination of a baaa moiety happened at one side chain in the process of the cyclocondensation and transmetallation. The X-ray structure of the complex shows that the macrocyclic ligand is asymmetric, where the coordination polyhedron of one Mn atom, six-coordinate, is distortedly octahedral and that of the other Mn atom, seven-coordinate, is distortedly pentagonal-bipyramidal. The complex has been investigated on its variable temperature magnetic behavior together with ESR spectral and electrochemical properties.