Copper-(I) and -(II) complexes with tertiary linear polyamines of the type Me2NCH2(CH2NMeCH2)nCH2NMe2(n= 1–4)

Abstract

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 Cu^I in aqueous solutions. On the other hand 2,5,8-trimethyl-2,5,8-triazanonane, does not. This indicates that the stabilization of Cu^I 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 Cu^II and Lⁱ. The nature of the complexes present in these solutions is discussed.