Ternary copper(II) complexes with N-carboxymethyl-L-prolinato(2) ion and imidazole or creatinine: A comparative study of the interligand interactions influencing the molecular recognition and stability Tribet, Magaly Cobelo, Verta Sicilia Zagra, Aurora G. Navarrete Casas, Ricardo Choquesillo Lazarte, Duane González Pérez, Josefa María Castiñeiras, Alfonso Niclos Gutiérrez, Juan Financial support from ERDF-EC, MEC-Spain (research project BQU2002-04523-C02) and FIS-MSC-Spain (research project PI021029) are gratefully acknowledged. DChL thanks to Prof. Castiñeiras for a research stay in his Group at University of Santiago de Compostela. The compounds {[Cu(CMP)(Him)] Æ H2O}n (I) and [Cu(CMP)(crea)H2O] Æ 3H2O (II) were synthesized and characterized by Xray diffraction, thermal, spectral and magnetic methods (CMP = N-carboxymethyl-;L-prolinato(2 ) ion, Him = imidazole and crea = creatinine). Appropriate structural comparison with other compounds such as {[Cu(CMP)(H2O)] Æ H2O}n, [Cu(crea)2Cl2] and [Cu(dipeptide)(crea)(H2O)x] Æ nH2O (x = 0 or 1) have been made in order to prove that crea can act as an imidazole-like ligand (because it is able to promote the same fac- to mer-CMP tridentate conformational change in copper(II) complexes) as well as to discuss the interligand interactions which control the Cu(CMP) complex-crea molecular recognition processes. In contrast to that found in related ternary complexes, we have concluded that direct CMP–crea interligand interactions are missing in the Cu–CMP– crea complex due to the inappropriate correspondence between the donor and/or acceptor H-bonding properties of these ligands. CMP can only act as H-acceptor by its two terminal carboxylate group, and crea can display H-donor and H-acceptor roles by its exocyclic –NH2 and O moieties, respectively. That promotes the reinforcement of the Cu–N(crea) bond by a bridge –N– H(crea)O(aqua) (2.867(3) A˚ , 176.4˚). 2025-03-31T12:21:37Z 2025-03-31T12:21:37Z 2005-07 journal article M. Tribet et al. / Journal of Inorganic Biochemistry 99 (2005) 1424–1432. https://doi.org/10.1016/j.jinorgbio.2005.03.012 https://hdl.handle.net/10481/103357 10.1016/j.jinorgbio.2005.03.012 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ embargoed access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Elsevier