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Hydroxonium hydrate tris(2,4,6-triamino-1,3,5-triazin-1-ium) bis[bis(pyridine-2,6-dicarboxylato)cuprate(II)] pyridine-2,6-dicarboxylic acid hexahydrate  [cached]
Hossein Aghabozorg,Jafar Attar Gharamaleki,Marilyn M. Olmstead,Zohreh Derikvand
Acta Crystallographica Section E , 2009, DOI: 10.1107/s1600536809000828
Abstract: The reaction of copper(II) nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2) and 2,4,6-triamino-1,3,5-triazine (melamine) in aqueous solution in a 1:2:2 molar ratio gave the title compound, (H5O2)(C3H7N6)3[Cu(C7H3NO4)2]2·C7H5NO4·6H2O. The hydroxonium hydrate (H5O2)+, also known as the Zundel cation, resides on a twofold rotation axis. The O—H distance is 1.274 (14) , the O...O distance is 2.518 (5) , and the O—H—O angle is 162 (8)°. One of the melamine H+ cations, the uncoordinated pydcH2, and two water molecules also reside on crystallographic twofold axes. The CuII atom has a tetragonally distorted octahedral coordination environment. The structure features extensive hydrogen bonding, with 21 distinct interactions. There is also a centrosymmetric C=O...π interaction with an O...centroid distance of 3.288 (3) . The structure is similar to a mixed-valence manganese(II/III) structure but shows interesting differences in the metal-atom coordination. One of the water molecules is equally disordered with respect to a twofold axis.
Tetrakis(2,4,6-triamino-1,3,5-triazin-1-ium) tris(pyridine-2,6-dicarboxylato)calcate(II) hexahydrate  [cached]
Hossein Aghabozorg,Shirin Daneshvar,Andya Nemati
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808022873
Abstract: The title compound, (C3H7N6)4[Ca(C7H3NO4)3]·6H2O or (tataH)4[Ca(pydc)3]·6H2O (where tata is 2,4,6-triamino-1,3,5-triazine and pydcH2 is pyridine-2,6-dicarboxylic acid), was obtained by reaction of Ca(NO3)2·4H2O with the proton-transfer compound (tataH)2(pydc) in aqueous solution. The [Ca(pydc)3]4 anion has twofold crystallographic symmetry. It is a nine-coordinate CaII complex with a distorted tricapped trigonal-prismatic coordination geometry. The structure also contains four tataH+ cations and six uncoordinated water molecules. There are extensive O—H...O, O—H...N, N—H...O, N—H...N and C—H...O hydrogen bonds in the crystal structure.
Bis(2,4,6-triamino-1,3,5-triazin-1-ium) pyrazine-2,3-dicarboxylate tetrahydrate: a synchrotron radiation study  [cached]
Hossein Eshtiagh-Hosseini,Azam Hassanpoor,Laura Canadillas-Delgado,Masoud Mirzaei
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536810017290
Abstract: The title compound, 2C3H7N6+·C6H2N2O42 ·4H2O or (tataH)2(pzdc)·4H2O, was synthesised by a reaction between pyrazine-2,3-dicarboxylic acid (H2pzdc) as a proton donor and 2,4,6-triamino-1,3,5-triazin (tata) as a proton acceptor. In the crystal structure, an extensive series of O—H...O, O—H...N, N—H...O and N—H...N hydrogen bonds generates a three-dimensional framework with the hydrogen bonding involving most donor and acceptor centers. π–π stacking interactions are also observed between adjacent triazine rings, with centroid–centroid distances of 3.4994 (8) and 3.5922 (7) .
Bis(2,4,6-triamino-1,3,5-triazin-1-ium) tris(pyridine-2,6-dicarboxylato)zirconate(IV) tetrahydrate
Shirin Daneshvar,Hossein Aghabozorg,Faranak Manteghi
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808029887
Abstract: The title compound, (C3H7N6)2[Zr(C7H3NO4)3]·4H2O or (tataH)2[Zr(pydc)3]·4H2O (tata is 2,4,6-triamino-1,3,5-triazine and pydcH2 is pyridine-2,6-dicarboxylic acid), was obtained by reaction between pydcH2, tata and zirconyl chloride octahydrate in aqueous solution. In the structure, the ZrIV atom is nine-coordinated by three (pydc)2 groups, resulting in an anionic complex which is balanced by two (tataH)+ cations. One of the NH2 groups shows positional disorder, with site occupation factors of 0.60 and 0.40. There are four uncoordinated water molecules (one of which is disordered with occupation factors of 0.70 and 0.30) in the crystal structure. Several intermolecular interactions, including O—H...O, O—H...N, N—H...O, N—H...N, C—H...O and C—H...N hydrogen bonds, a C—O...π interaction [O...Cg 3.89, C...Cg 4.068 (3) ; C—O...Cg 89° where Cg is the centroid of the triamine ring], and π–π stacking [with centroid–centroid distances of 3.694 (2) and 3.802 (2) ] are also present.
Bis(2,4,6-triamino-1,3,5-triazin-1-ium) hexaaquacobalt(II) bis[bis(pyridine-2,6-dicarboxylato)cobaltate(II)] tetrahydrate
Hossein Aghabozorg,Jafar Attar Gharamaleki,Shirin Daneshvar,Mohammad Ghadermazi
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536807066032
Abstract: The title compound, (C3H7N6)2[Co(H2O)6][Co(C7H3NO4)2]2·4H2O, or (tataH)2[Co(H2O)6][Co(pydc)2]2·4H2O (where tata is 2,4,6-triamino-1,3,5-triazine and pydc is pyridine-2,6-dicarboxylic acid), was obtained by reaction of Co(NO3)2·6H2O with the proton-transfer compound (tataH)2(pydc) in aqueous solution. The [Co(pydc)2]2 anion is a six-coordinate CoII complex with a distorted octahedral coordination geometry. The structure also contains hexaaquacobalt(II) cations (site symmetry overline{1}), (tataH)+ cations and uncoordinated water molecules. The two(pydc)2 ligands in each [Co(pydc)2]2 anion are almost perpendicular to each other [dihedral angle between their mean planes = 82.3 (1)°]. There is extensive O—H...O, N—H...N, O—H...N and C—H...O hydrogen bonding in the structure, as well as π–π stacking between (pydc)2 ligands with an interplanar distance of 3.484 (15) .
Bis(2,4,6-triamino-1,3,5-triazin-1-ium) hydrogen phosphate trihydrate  [cached]
Xue-Mei Li,Si-Si Feng,Fan Wang,Qi Ma
Acta Crystallographica Section E , 2010, DOI: 10.1107/s1600536809054798
Abstract: In the title hydrated molecular salt, 2C3H7N6+·HPO42 ·3H2O, three of the O atoms of the hydrogen phosphate anion are disordered over two positions, with relative occupancies of 0.763 (1) and 0.237 (1). In the crystal, the components are linked by N—H...N, N—H...O and O—H...O hydrogen bonds
μ-4,4′-Bipyridine-bis[aqua(4-hydroxypyridine-2,6-dicarboxylato)copper(II)]
Xiao-Li Chen,Ya-Li Qiao,Lou-Jun Gao,Hua-Li Cui
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812004758
Abstract: The title compound, [Cu2(C7H3NO5)2(C10H8N2)(H2O)2], exhibits a centrosymmetric binuclear molecule. Each completely deprotonated 4-hydroxypyridine-2,6-dicarboxylic acid molecule assumes a tridentate chelating coordination mode. The square-pyramidal coordination geometry around the CuII ion is completed by the bridging bipyridine ligand and an apical water molecule. Adjacent complexes are connected via O—H...O and C—H...O hydrogen bonds to generate a three-dimensional supramolecular structure.
catena-Poly[[[aquacadmium(II)]bis(μ-4-hydroxypyridine-2,6-dicarboxylato)[aquacadmium(II)]di-μ-aqua] tetrahydrate]  [cached]
Hossein Aghabozorg,Neda Ilaie,Mohammad Heidari,Faranak Manteghi
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536808030869
Abstract: The title polymeric compound, {[Cd2(C7H3NO5)2(H2O)4]·4H2O}n or {[Cd2(hypydc)2(H2O)4]·4H2O}n (where hypydcH2 is 4-hydroxypyridine-2,6-dicarboxylic acid), was synthesized by the reaction of cadmium(II) nitrate hexahydrate with 4-hydroxypyridine-2,6-dicarboxylic acid and propane-1,3-diamine, in a 1:2:2 molar ratio in aqueous solution. The compound is a seven-coordinate binuclear polymeric complex with distorted pentagonal bipyramidal geometry around CdII [Cd—O = 2.247 (4)–2.474 (3) ]. In the binuclear monomeric units, the central atoms join together by O atoms of two bridging tridentate (hypydc)2 ligands, and the polymer propagates via two bridging water molecules that link each CdII centre of one monomer to the adjacent neighbour. Propane-1,3-diamine (pn) does not appear in the product but plays a role as a base. Intermolecular O—H...O and C—H...O hydrogen bonds, and π–π stacking interactions, with distances of 3.725 (3) and 3.766 (3) , connect the various components.
Bis(guanidinium) bis(4-hydroxypyridine-2,6-dicarboxylato-κ3O2,N,O6)nickelate(II) dihydrate  [cached]
Hossein Aghabozorg,Elham Motyeian,Jafar Attar Gharamaleki,Janet Soleimannejad
Acta Crystallographica Section E , 2008, DOI: 10.1107/s1600536807065026
Abstract: The reaction of nickel(II) nitrate hexahydrate, guanidine (G) and 4-hydroxypyridine-2,6-dicarboxylic acid (hypydcH2) in a 1:2:2 molar ratio in aqueous solution resulted in the formation of the title compound, (CH6N3)2[Ni(C7H3NO5)2]·2H2O or (GH)2[Ni(hypydc)2]·2H2O. The six donor atoms of the two 4-hydroxypyridine-2,6-dicarboxylate or (hypydc)2 ligands form a distorted octahedral arrangement around the NiII centre. Considerable C—O...π stacking interactions between the CO groups of carboxylate fragments and the pyridine rings of (hypydc)2 with a distance of 3.3212 (8) are observed. In the crystal structure, a wide range of noncovalent interactions consisting of hydrogen bonding (of the types O—H...O and N—H...O), ion pairing, and π–π [centroid–centroid distance 3.8037 (5) ], N—H...π and C—O...π stacking interactions connect the various components into a supramolecular structure.
Diacetato[N,N′-bis(2-pyridylmethylidene)cyclohexane-1,2-diamine]manganese(II) hexahydrate
In-Chul Hwang,Kwang Ha
Acta Crystallographica Section E , 2008, DOI: 10.1107/s160053680800353x
Abstract: The asymmetric unit of the title compound, [Mn(C2H3O2)2(C18H20N4)]·6H2O, consists of a neutral MnII complex with six solvent water molecules. In the complex, the Mn2+ ion is eight-coordinated in a distorted square-antiprismatic environment by four N atoms from the tetradentate ligand N,N′-bis(2-pyridylmethylidene)cyclohexane-1,2-diamine (bpic) and four O atoms from two acetate ligands. The compound displays intermolecular O—H...O hydrogen-bond interactions to form various kinds of ring structures and cyclic water clusters.
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