In the crystal structure of the title compound, C4H6N3 +·C7H4NO5 −·H2O, inter­molecular N—H⋯N, N—H⋯O and O—H⋯O hydrogen bonds link the cations and anions into almost planar sheets parallel to (102). These hydrogen-bonded sheets are packed into the crystal with the formation of centrosymmetric voids of 68 Å3, which are filled by the water mol­ecules, each of which is disordered over four positions.

Four new complexes of chelidamic acid (H3cda) in the presence\ud of 2-aminopyrimidine (apym) or 2,4,6-triamino-1,3,5-triazine\ud (tata) as external ligands, namely (apymH)[VO2(Hcda)]·H2O (1),\ud [Ni(Hcda)(apym)(H2O)2]·H2O (2), (apymH)[Fe(Hcda)2] (3), and (tataH)\ud 2(tata)2[Ca2(cda)2(H2O)6]·H2O (4) were synthesized. X-ray diffraction\ud analysis of 1-4 revealed the formation of 3D frameworks\ud generally involving weak interactions (mainly H-bonds)\ud between metal complexes of chelidamic acid, protonated or\ud deprotonated external ligands apym or tata and co-crystallized\ud water molecules. Some complexes present remarkable assemblies\ud in the solid state governed by unconventional noncovalent\ud interactions that have been analyzed by means of DFT\ud calculations. Solution studies were also performed to fully characterize\ud the new compounds

No abstract

4-Hydroxypyridine-2,6-dicarboxylic acid (chelidamic acid, cdaH(3)) reacts with MnCl(2)·2H(2)O in the presence of 2-amino-4-methylpyrimidine in water to afford the tetranuclear title complex, [Mn(4)(C(8)H(3)NO(5))(4)(H(2)O)(10)]·3.34H(2)O, built through carboxylate bridging. The tetranuclear complex sits on a centre of inversion at (½, ½, ½). In the crystal, discrete undecameric (H(2)O)(10.34) water clusters (involving both coordinated and uncoordinated water molecules, with one site of an uncoordinated water molecule not fully occupied) assemble these tetranuclear Mn(II) complex units via an intricate array of hydrogen bonding into an overall three-dimensional network. The degree of structuring of the (H(2)O)(10.34) supramolecular association of water molecules observed in the present compound, imposed by its environment and vice versa, will be discussed in comparison to that observed for the (H(2)O)(14) supramolecular clusters in the case of the dinuclear complex [Mn(2)(cdaH)(2)(H(2)O)(4)]·4H(2)O [Ghosh et al. (2005). Inorg. Chem. 44, 3856-3862].

No abstract