Coordination Chemistry Of 1,4-Bis-Carboxymethylcyclam, H-2(1,4-Bcc)

Zinc metal reduction of the cobalt(III) complex [Co(1,4-bcc)](+)(1,4-bcc = 1,4-bis-carboxymethylcyclam) produces the corresponding cobalt(II) complex which crystallises as the coordination polymer {[Co(1,4- bcc)]ZnCl2}(n). A method has been developed for removal of the cobalt(III) ion from [Co(1,4-bcc)](+) and isolation of the free ligand as its hydrochloride salt, H-2(1,4-bcc)center dot 4HCl. This has been used for the preparation of new metal complexes, and the syntheses and characterisation of the copper(II), nickel(II), zinc(II) and chromium(III) complexes containing the 1,4- bcc ligand are described. X-Ray crystal structures of {[Co(1,4-bcc)]ZnCl2}(n)center dot 2.5H(2)O, {[Cu(1,4-bcc)]CuCl2}(n)center dot 0.25MeOH center dot H2O and [Cu(1,4-bcc)H]ClO4 show the complexes to have the trans(O) geometry of the 1,4- bcc ligand, while the structure of [Cr(1,4-bcc)H-0.5](ClO4)(1.5)center dot EtOH exhibits the cis(O) configuration.