Equilibrium studies. Complex formation of 4-azaheptane-1,7-diamine, 4,8-diazanonamine, and 4-aza-4-methylheptane-1,7-diamine with copper(II) ions and protons in aqueous solution

Equilibrium constants are reported for the protonation of the linear triamine, 4-azaheptane-1,7-diamine (4NH-hd), and its N-methyl analogues, 4,8-diazanonamine (4,8NH-nam) and 4-aza-4-methylheptane-1,7-diamine (4NH-4Me-hd),I= 0.1M(NaCl), 25°C. Formation constants and spectrophotometric data are presented for the complexes [CuL(H2O)]2+ and [CuL(OH)]3+ formed by each ligand. Data are compared with those for analogous triamines.