The supramolecular structure ofN-(6-amino-3,4-dihydro-3-methyl-5-nitroso-4-oxopyrimidin-2-yl)glycylglycinate contains a unique O—H...N(nitroso) hydrogen bond

Abstract

Key indicatorsSingle-crystal X-ray study T = 150 K Mean '(C±C) = 0.002 A Ê R factor = 0.044 wR factor = 0.122 Data-to-parameter ratio = 12.8For details of how these key indicators were automatically derived from the article, see

Adsorption of Designed Pyrimidine Derivative Ligands on an Activated Carbon for the Removal of Cu(II) Ions from Aqueous Solution

“…The electron withdrawing character of the C5NO and C6O substituents, determine short C5−N and N−O bond lengths in C5NO groups and relatively longer bond distances in the HN aminoac −C2N3C4N fragment. This indicates strong polarization of the aromatic moieties of all of the compounds with the negative charge at the former and the positive one at the second. , This fact reduces the basicity of the N3 ring atom. In fact, this atom remains unprotonated in aqueous solutions of these ligands even at pH values below 2 (see below).…”

“…This indicates strong polarization of the aromatic moieties of all of the compounds with the negative charge at the former and the positive one at the second. 14,16 This fact reduces the basicity of the N3 ring atom. In fact, this atom remains unprotonated in aqueous solutions of these ligands even at pH values below 2 (see below).…”

“…As already commented, compounds 3 − 7 were synthesized following a previously reported method, and their molecular structures were solved by single-crystal X-ray diffraction methods. − Optimum geometries of the molecules were calculated from the conformations corresponding to the global minimum by using the MM2 algorithm ( ChemBats3D , CambridgeSoft Corp.) . The geometry was optimized without any constraints, allowing all atoms, bonds, and dihedral angles to change simultaneously.…”

“…The synthesis methods have already been described. [14][15][16] Thus, in this paper, we report the adsorption of receptors 3-7 on the AC at different pH. Moreover, the adsorption capacities of the carbon and the carbon-receptor adsorbents to Cu(II) have also been measured at different pH values.…”

“…Production of compounds 3 − 7 was carried out by substitution of four l -amino acids (alanine, methionine, serine, and valine) and the dipeptide glycylglycine, respectively, at the C2 position of the compound 4-amino-1-methyl-2-methoxy-5-nitroso-6-oxo-pyrimidine (Chart ). The synthesis methods have already been described. − …”