Copper complexes of some tetradentate pyrazolyl amines

• Published in: Inorganica Chimica Acta Vol. 142; no. 1; pp. 95 - 100
• Main Authors: Addison, A.W., Palaniandavar, M., Driessen, W.L., Paap, F., Reedijk, J.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.02.1988; Elsevier Science
• Subjects: Chemistry; Coordination compounds; Exact sciences and technology; Inorganic chemistry and origins of life; Preparations and properties; Chemical reduction; Divalent metal Complexes; Five membered ring; Copper II Complexes; Nitrogen heterocycle; Complexes Mixed; Preparation; Organic ligand; Transition metal Complexes; EPR spectrum; Tetradentate ligand; Electrochemical reaction
• ISSN: 0020-1693; 1873-3255
• DOI: 10.1016/S0020-1693(00)80665-9

Four tetradentate nitrogen donor ligands have been prepared by condensation of N-hydroxymethylpyrazoles with ethylenediamines. These ligands are varied by methylation of the pyrazole rings (edbd) or the aminonitrogens (debp), or both (debd). Copper(II) complexes of the type CuL(ClO 4) 2 have been isolated with L = debp, edbp, edbd. For L = debd, the adducts salts Cu(debd)(dMp)X 2, with X = ClO 4 −, BF 4 − and dMp = 3,5-dimethylpyrazole, were obtained. The compounds were characterized by their absorption (d-d) and EPR spectra. All four undergo quasi-reversible electrochemical reduction in methanol, the redox potentials being correlated with the degree of ligand methylation. The copper(I) forms are relatively unstable, and also bind carbon monoxide with different affinities.