Synthesis, characterization and X-ray crystal structure of cyclam derivatives.: Part III.: Formation and electrochemically induced isomerization of copper complexes of 1,8-bis(N,N-dimethylcarbamoylmethyl)-4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane

The synthesis, spectroscopic study and X-ray structural data of two different isomers of [copper(II)1,8-bis(N,N-dimethylcarbamoylmethyl) -4,11-dimethyl-1,4,8,11-tetraazacyclotetradecane] (BF4)(2) are reported. This study clearly shows that the two complexes are of I and trans-III configurations, respectively (Bosnich representation). The electrochemical activation of these two derivatives is also reported as well as that of related compounds. Although interconversion between the two copper species cannot be chemically induced, the electrochemical reduction of both complexes promotes the isomerization process. (C) 2000 Academic des sciences/Editions scientifiques et medicales Elsevier SAS.