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 wi th Mn(II)(ClO4)(2). 6H(2)O has resulted in the generation of a dinuclear mi xed-valence Mn(II)Mn(III) complex of a tetraimine macrocyclic Schiff base w ith a single carboxylic arm, in which unusual group elimination of a baaa m oiety happened at one side chain in the process of the cyclocondensation an d transmetallation. The X-ray structure of the complex shows that the macro cyclic ligand is asymmetric, where the coordination polyhedron of one Mn at om, 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 wi th ESR spectral and electrochemical properties. (C) 2000 Elsevier Science S .A. All rights reserved.