TY - JOUR A1 - Comba, P. A1 - Emmerling, Franziska A1 - Jakob, M. A1 - Kraus, Werner A1 - Kubeil, M. A1 - Morgen, M. A1 - Pietzsch, J. A1 - Stephan, H. T1 - Copper(II) chemistry of the functionalized macrocycle cyclam tetrapropionic acid N2 - 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. KW - Copper(II) KW - Chemistry PY - 2013 DO - https://doi.org/10.1039/c2dt32356g SN - 1477-9226 SN - 1477-9234 SN - 1364-5447 VL - 42 IS - 17 SP - 6142 EP - 6148 PB - RSC CY - Cambridge AN - OPUS4-28075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -