作者:Angel Garcı́a-Raso、Juan J. Fiol、Bartomeu Adrover、Amparo Caubet、Enrique Espinosa、Ignasi Mata、Elies Molins
DOI:10.1016/s0277-5387(02)01010-0
日期:2002.6
Two ternary complexes [Cu(ala-gly)(isocyt)(H2O)]-H2O (1) and [Cu(L-tyr-gly) (isocyt)].3H(2)O (2) have been prepared and characterised by X-ray diffraction, optical, ESR and IR spectral data. Both compounds exist as slightly distorted square-planar complexes, with the four co-ordination sites occupied by the tridentate peptidic dianion [oxygen carboxylic O(7), nitrogen amidic N(13) and nitrogen aminic N(10)] and the N(3) of the pyrimidine base. In complex 1, obtained as a racemic compound, an additional weak axial interaction exists between the oxygen of a water molecule OW1 and the copper atom [Cu-OW1 distance 2.50 Angstrom]. Spectroscopic data are in accordance with the crystal structures. The isocytosine ligand is approximately orthogonal to the Cu-peptide moiety independently of the nature of the lateral chain. This disposition of the nucleobase contrasts with the coplanarity of the previously described Cu(II)-glygly-creatinine complex. (C) 2002 Elsevier Science Ltd. All rights reserved.