Copper-( I ) and -( II ) complexes with tertiary linear polyamines of the type Me 2 NCH 2 (CH 2 NMeCH 2 ) n CH 2 NMe 2 (n= 1–4)

2,5,8,11-Tetramethyl-2,5,8,11-tetraazadodecane, 2,5,8,11,14-pentamethyl-2,5,8,11,14-pentaazapentadecane, and 2,5,8,11,14,17-hexamethyl-2,5,8,11,14,17-hexaazaoctadecane, form stable complexes with CuI in aqueous solutions. On the other hand 2,5,8-trimethyl-2,5,8-triazanonane, does not. This indicates that the stabilization of CuI by tertiary amine ligands in aqueous solutions requires at least four nitrogens. The electronic spectra and the electrochemical properties of the [CuLi]2+ complexes over a wide pH range were studied and potentiometric titrations were made of solutions containing equimolar concentrations of CuII and Li. The nature of the complexes present in these solutions is discussed.