ONE-POT SYNTHESIS, PHYSICOCHEMICAL CHARACTERIZATION AND CRYSTAL-STRUCTURES OF ,4,8,11-TETRAAZACYCLOTETRADECANE)DICHLOROIRON(III) AND ,4,8,11-TETRAAZACYCLOTETRADECANE)DICHLOROIRON(III) COMPLEXES

The synthesis and characterization of cis-and trans-[Fe(cyclam)Cl-2]() (cyclam = 1,4,8,11-tetraazacyclotetradecane) are described. The assi gnment of geometrical configuration to these complexes has been made o n the basis of their infrared spectra in the 800-900 cm(-1) region. In addition, the molecular structures of the cis and trans derivatives w ere determined by X-ray diffraction. Both complexes have a d(5) electr onic system, the cis and trans species being respectively in a high sp in and a low spin configuration. These two isomers are fully character ized by electrochemistry and they are simultaneously observed in the r eaction mixture by cyclic voltammetry. This study shows that the react ivity towards dioxygen of the two reduced isomers is different, and th at the formation of the oxygenated species is not observed in some sol vents.