Mixed cobalt(III) complexes with 1,4,8,11-tetraazacyclotetradecane (cyclam) and α,ω-dicarboxylato ligands

Abstract

By direct reaction, four mixed mononuclear cobalt(III) complexes with 1,4.8,11-tetraazacycloletradecane (cyclam) and dicarboxylato ligands (dic: malc nato, succinato, glutarato, and adipato ions), of the general formula [Co(dic)(cyclam)]ClO 4 were obtained. It has been postulated that the geometry of all complexes is a deformed octahedron with the cyclam in a folded configuration and the bidentale dicarboxylate in the cis position bound through the two oxygen atoms of both carboxylic groups. For the glutarato-and adipato-complexes the supposed structure is an eight-and nine-membered chelate ring, respectively. The complexes were characterized by elemental analysis, ion-exchange chromartography, as well as electronic and IR spectroscopy.