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 differe nt isomers of [copper(II)1,8-bis(N,N-dimethylcarbamoylmethyl) -4,11-dimethy l-1,4,8,11-tetraazacyclotetradecane] (BF4)(2) are reported. This study clea rly shows that the two complexes are of I and trans-III configurations, res pectively (Bosnich representation). The electrochemical activation of these two derivatives is also reported as well as that of related compounds. Alt hough interconversion between the two copper species cannot be chemically i nduced, the electrochemical reduction of both complexes promotes the isomer ization process. (C) 2000 Academic des sciences/Editions scientifiques et m edicales Elsevier SAS.