Study of protonation and Zn(II), Cd(II), Cu(II) and Mn(II) complexation with a glutamic acid N-pyrimidine derivative:: Crystal structure of a neutral Cd(II) complex of the bianionic ligand

The compound N-(4-amino-1-methyl-5-nitroso-6-oxo-1,6-dihydropyrimidin-2-yl)-(s)-glutamic acid (H3L) was synthesised and structurally characterised by analytical methods and H-1, C-13 and N-15 NMR spectroscopy. This compound (H3L) shows the same topology as other model receptors previously used to develop chemical functionalization at the surface of an active carbon when they adsorb on it. Protonation of H3L and its coordination ability towards Cd2+, Zn2+, Cu2+ and Mn2+ ions in water solution was also studied by potentiometric methods, UV-Vis and H-1, C-13 NMR spectroscopies. The obtained results allow us to fit the operative conditions for the use of the activated carbon-H3L adsorbent for the retaining of the above-mentioned metal ions in aqueous solutions. The molecular structure of {[Cd(HL)H2O] center dot 3H(2)O}(n) was solved by single-crystal X-ray diffraction methods. (c) 2007 Elsevier Ltd. All rights reserved.