Cu(II), Ni(II) and Zn(II) mononuclear building blocks based on new polynucleating azomethine ligand : Synthesis and characterization
Zdyb, K., Plutenko, M. O., Lampeka, R. D., Haukka, M., Ostrowska, M., Fritsky, I. O., & Gumienna-Kontecka, E. (2017). Cu(II), Ni(II) and Zn(II) mononuclear building blocks based on new polynucleating azomethine ligand : Synthesis and characterization. Polyhedron, 137, 60-71. doi:10.1016/j.poly.2017.07.009
DisciplineEpäorgaaninen ja analyyttinen kemia
© 2017 Elsevier Ltd. This is a final draft version of an article whose final and definitive form has been published by Elsevier. Published in this repository with the kind permission of the publisher.
Five new mononuclear complexes formed by the polynucleating ligand 2-[1-(3,5-dimethyl)pyrazolyl]-2-hydroxyimino-N′-[1-(2-pyridyl)ethylidene]acetohydrazide (HL): [Ni(L)(HL)]ClO4·2CH3OH (1), [Ni(L)2]·CH3OH (2), [Zn(L)(HL)]ClO4·2CH3OH (3), [Zn(L)2]·CH3OH (4) and [Cu(L)2]·CH3OH (5) were synthesized and characterized by elemental analysis, mass-spectrometry, IR-spectroscopy and X-ray analysis. The complexes reveal distorted octahedral N4O2 coordination arrangement formed by both protonated and deprotonated (1, 3) or two deprotonated ligand molecules (2, 4, 5). The presence of non-coordinated oxime and pyrazole groups resulted in the formation of extensive systems of hydrogen bonds in the crystal packing of 1–5. Potentiometric titrations, ESI-MS and spectrophotometric studies of complex formation in MeOH/H2O solutions indicated the presence of mono- and polynuclear complexes with Cu(II), Ni(II) and Zn(II) ions. The solution studies carried out for an excess of Cu(II) over HL ligand (2:1 and 3:2 M ratio) indicated also the formation of polynuclear Cu3L2Hx species, with an involvement of additional nitrogen donors in copper coordination. In binuclear complex [Cu2(L)2(DMF)2](ClO4)2·DMF(6) obtained in solid state, the Cu(II) coordination, analogous to the one in 1–5, was supported by pyrazole N atom. ...