Bis-macrocyclic ligands with two ferrocenyl end groups, and their tetranuclear dicopper(I) compounds

A series of bismacrocyclic ligands with two ferrocenyl groups, exo/endo-1,1':1 ",1'''-[1,2,4,5-tetrakis(5-aza-2- thiahexa-5-enyl)benzene]bisferrocene (exo/endo-FeBeFe), 1,1':1 ",1'''-[1,2:1',2'-tetrakis(5-aza-2-thiahexa-5-enyl)-ethene]bisferrocene (1,2-FeEnFe), 1,1': 1 ",1'''-[1,1':2,2'-tetrakis(5-aza-2-thiahexa-5-enyl)ethene]biseferrocene (1,1- FeEnFe), 1,1': 1 " 1'''-[tetrakis(5-aza-2-thiahexa-5-enyl)methane]bisferrocene (FeMeFe), and their dicopper(I) compounds have been synthesized and characterized (electrochemistry, IR, NMR and Mossbauer spectroscopy). The molecular structure of endo-FeBeFe has been determined by X-ray structure analysis and the copper(I)induced discrimination of the exo- and endo-isomers of FeBeFe has been investigated by H-1 NMR spectroscopy. The interaction between copper and iron in the tetranuclear compounds is discussed on the basis of the electrochemical and spectroscopic data.