Nitrosalicylatocopper(II) complexes with chelating pyridine derivatives

Three new nitrosalicylatocopper(II) complexes have been prepared and characterized. Compounds of the composition Cu(5-NSal)₂(2-ampy)₂ (1), Cu(5-NSal)₂(2-hmpy)₂ (2) and Cu(3,5-DNSal)₂(2-hmpy)₂ (3), where 2-ampy = (2-aminomethyl)pyridine, 2-hmpy = (2-hydroxymethyl)pyridine, 5-NSal = 5-nitrosalicylate anion and 3,5-DNSal = 3,5-dinitrosalicylate anion, were characterized by elemental analyses, EPR and IR spectroscopy. EPR spectra are consistent with the dx_2-y2ground electronic state. Spectral properties have shown “classic” monodentate coordination of 5-nitrosalicylate anion. Similarly, bonding mode of the 3,5‑dinitrosalicylate anion in (3) is assumed to be unidentate via the carboxyl group, which is surprising compared with the previously studied complex, where the preferred coordination via the phenolate group anion was observed.