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Updated: Dec 13, 2025

Structure and Coordination Determination of Peptide-metal Complexes Using 1D and 2D 1H NMR
Published on: December 16, 2013
Five-Coordinated Geometries from Molecular Structures to Solutions in Copper(II) Complexes Generated from
Franz A Mautner1, Roland C Fischer2, Ana Torvisco2
1Institut für Physikalische und Theoretische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria.
Abstract:
A novel series of mononuclear five-coordinated pseudohalido-Cu(II) complexes displaying distorted square bipyramidal: [Cu(L1)(NCS)2] (1), [Cu(L2)(NCS)2] (2) and [Cu(L3)(NCS)]ClO4 (5) as well as distorted trigonal bipyramidal: [Cu(isp3tren)(N3)]ClO4 (3), [Cu(isp3tren)(dca)]ClO4 (4) and [Cu(tedmpza)(dca)]ClO4·0.67H2O (6) geometries had been synthesized and structurally characterized using X-ray single crystal crystallography, elemental microanalysis, IR and UV-vis spectroscopy, and molar conductivity measurements. Different N-donor amine skeletons including tridentate: L1 = [(2-pyridyl)-2-ethyl)-(3,4-dimethoxy)-2-methylpyridyl]methylamine and L2 = [(2-pyridyl)-2-ethyl)-(3,5-dimethyl-4-methoxy)-2-methyl-pyridyl]methylamine, and tetradentate: L3 = bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl)-[2-(3,4-dimethoxy-pyridylmethyl)]amine, tedmpza = tris[(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]amine and isp3tren = tris[(2-isopropylamino)ethyl)]amine ligands were employed. Molecular structural parameters such as nature of coligand, its chelate ring size and steric environment incorporated into its skeleton, which lead to adopting one of the two limiting geometries in these complexes and other reported compounds are analyzed and correlated to their assigned geometries in solutions. Similar analysis were extended to other five-coordinated halido-Cu(II) complexes.
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