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A trinuclear nickel complex, [Ni3(C9H10NO3)6(CH3O)]·4CH4O, was synthesized and characterized as a neutral cluster containing the incomplete cubane {Ni3(μ1-O)(μ2-O)2(μ3-O)} core of 2M3–1 topology. The three nickel cations show similar octahedral coordination, {Ni(μ1-O)(μ2-O)2(μ3-O)(μ1-N)2}; the positive charge is balanced by six tyrosinate ligands and one methoxide ion. The mean oxidation state of each NiII ion is therefore +2.33. The common coordination modes, chelating (via the amino N and the carboxylate O atoms) and bridging (via the carboxylate O atom), are exhibited by the tyrosinates. Three interligand (intracluster) N—H
O hydrogen-bonding interactions stabilize the incomplete cubane-type moiety. Additional N—HO, O—HO and C—HO interactions are formed between clusters, and between the clusters and methanol molecules to regulate the spatial orientation of the tyrosinate and the assembly of the clusters in the crystal. The approximate equilateral triangular arrangement of the three nickel cations in the incomplete cubane-type moiety suggests the possible magnetic frustration, and the proximity of these metal cations indicates weak metallic bonds. The structure contains approximately 39% solvent-accessible volume between the clusters. This is filled with 17 molecules of disordered methanol and was modelled with SQUEEZE [Spek (2009). Acta Cryst. D65, 148–155]; the reported unit-cell characteristics do not take these molecules into account. The H atoms of the solvent molecules have not been included in the crystal data.
O hydrogen-bonding interactions stabilize the incomplete cubane-type moiety. Additional N—HO, O—HO and C—HO interactions are formed between clusters, and between the clusters and methanol molecules to regulate the spatial orientation of the tyrosinate and the assembly of the clusters in the crystal. The approximate equilateral triangular arrangement of the three nickel cations in the incomplete cubane-type moiety suggests the possible magnetic frustration, and the proximity of these metal cations indicates weak metallic bonds. The structure contains approximately 39% solvent-accessible volume between the clusters. This is filled with 17 molecules of disordered methanol and was modelled with SQUEEZE [Spek (2009). Acta Cryst. D65, 148–155]; the reported unit-cell characteristics do not take these molecules into account. The H atoms of the solvent molecules have not been included in the crystal data.metal-organic compoundsOpen access
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The crystal structure of the title compound, [Cu(SO4)(C12H8N2)2]·C2H5OH, arises from the assembly of the neutral complex [Cu(SO4)(C12H8N2)2] and an ethanol solvent molecule. The CuII ion is five-coordinate, surrounded by two pairs of N atoms from two independent N,N′-chelating 1,10-phenanthroline ligands, and one O atom of monodentate sulfate ligand, in a distorted trigonal-bipyramidal fashion. Spatial orientation of the ligands and the assembly in the solid state are stabilized by the C—HO hydrogen-bonding interactions, established between the O atoms (from the sulfate ligand and the ethanol molecule) and the neighbouring 1,10-phenanthroline molecules. There is also an offset face-to-face π–π stacking between the 1,10-phenanthroline ligands. The ethanol solvent molecule is disordered over two orientations in the ratio 0.663 (10):0.337 (10). The crystal examined was subject to racemic twinning and the refined twin fraction was 0.346 (19).
O hydrogen-bonding interactions, established between the O atoms (from the sulfate ligand and the ethanol molecule) and the neighbouring 1,10-phenanthroline molecules. There is also an offset face-to-face π–π stacking between the 1,10-phenanthroline ligands. The ethanol solvent molecule is disordered over two orientations in the ratio 0.663 (10):0.337 (10). The crystal examined was subject to racemic twinning and the refined twin fraction was 0.346 (19).organic compoundsOpen access
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The title compound, 2C3H7N6+·C6H7NO62−·3H2O, was obtained by mixing melamine and nitrilotriacetic acid in aqueous solution. There is proton transfer from the nitrilotriacteic acid to melamine to produce two melaminium cations and an internal proton transfer to generate the [HN(CH2COO)]2− zwitterion. The melaminium cations are arranged in hydrogen-bonded tapes formed by N—HN interactions. These tapes extend parallel to the [010] direction and are stacked parallel to the a axis at a mean separation of 3.3559 (11) Å. Between these tapes lie the anions and lattice water molecules. Further O—HO and N—HO hydrogen bonds exist between the water molecules, the anions, and the melaminium cations, generating a three-dimensional array. The crystal examined was found to be twinned by a twofold rotation about the direct lattice direction [100]. The two twin components were present in the ratio 0.5918:0.4082 (14).
N interactions. These tapes extend parallel to the [010] direction and are stacked parallel to the a axis at a mean separation of 3.3559 (11) Å. Between these tapes lie the anions and lattice water molecules. Further O—HO and N—HO hydrogen bonds exist between the water molecules, the anions, and the melaminium cations, generating a three-dimensional array. The crystal examined was found to be twinned by a twofold rotation about the direct lattice direction [100]. The two twin components were present in the ratio 0.5918:0.4082 (14).
