Copper(II) chemistry of the functionalized macrocycle cyclam tetrapropionic acid

• Verfasst von: Comba, Peter [VerfasserIn]
• Verfasst von: Jakob, Maik [VerfasserIn]
• Verfasst von: Morgen, Michael [VerfasserIn]
• Titel: Copper(II) chemistry of the functionalized macrocycle cyclam tetrapropionic acid
• Verf.angabe: Peter Comba, Franziska Emmerling, Maik Jakob, Werner Kraus, Manja Kubeil, Michael Morgen, Jens Pietzsch and Holger Stephan
• Jahr: 2013
• Jahr des Originals: 2012
• Umfang: 7 S.
• Fussnoten: First published 27 Nov 2012 ; Gesehen am 17.08.2018
• Titel Quelle: Enthalten in: Dalton transactions
• Ort Quelle: London : Soc., 1972
• Jahr Quelle: 2013
• Band/Heft Quelle: 42(2013), 17, Seite 6142-6148
• ISSN Quelle: 1477-9234
• DOI: doi:10.1039/C2DT32356G
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1580142761

Abstract

The CuII complex of H4TETP (H4TETP = 1,4,8,11-tetraazatetradecane-1,4,8,11-tetrapropionic acid) is five-coordinate with a distorted square-pyramidal structure (τ = 0.45; i.e. the geometry is nearly half-way between square-pyramidal and trigonal-bipyramidal) and a relatively long Cu-N and a short Cu-O bond; the comparison between powder and solution electronic spectroscopy, the frozen solution EPR spectrum and ligand-field-based calculations (angular overlap model, AOM) indicate that the solution and solid state structures are very similar, i.e. the complex has a relatively low “in-plane” and a significant axial ligand field with a dx2−y2 ground state. The ligand-enforced structure is therefore shown to lead to a partially quenched Jahn-Teller distortion and to a relatively low complex stability, lower than with the corresponding acetate-derived ligand H4TETA. This is confirmed by potentiometric titration and by the biodistribution with 64Cu-labeled ligands which show that the uptake in the liver is significantly increased with the H4TETP-based system.