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metal-organic compounds
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The title compound, (NH4)2[Zn(NCS)4]·2C12H24O6·H2O, the result of the reaction of ammonium thiocyanate, 18-crown-6 and zinc(II) chloride in aqueous solution, exhibits an unusual supramolecular structure. The Zn atom, two of the thiocyanate chains and a water molecule, disordered over two positions, lie on a mirror plane. The macrocycle adopts a conformation with approximate D3d symmetry. The ammonium molecules are contained within the bowl of the macrocycle via extensive N—H
O hydrogen bonds and the complex molecules are linked via N—HS hydrogen bonds, forming chains along the c-axis direction. The macrocycle is disordered over two positions [refined occupancy ratio = 0.666 (8):0.334 (8)]. The S atoms of two isothiocyanate ligands are disordered within and about the mirror plane.
O hydrogen bonds and the complex molecules are linked via N—HS hydrogen bonds, forming chains along the c-axis direction. The macrocycle is disordered over two positions [refined occupancy ratio = 0.666 (8):0.334 (8)]. The S atoms of two isothiocyanate ligands are disordered within and about the mirror plane.organic compoundsOpen access
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The title compound, C14H20N4O4·0.5H2O [systematic name: (2S)-5-{[amino(iminiumyl)methyl]amino}-2-{[(1Z)-4-methoxy-2-oxidobenzylidene]azaniumyl}pentanoate hemihydrate], has been synthesized by the reaction of L-arginine and 4-methoxysalicylaldehyde and crystallizes with two independent substituted L-arginine molecules and one water molecule of solvation in the asymmetric unit. Each molecule exists as a zwitterion and adopts a Z configuration about the central C=N. The molecular conformation is stabilized by strong intramolecular N—HO hydrogen bonds that generate S(6) and S(10) ring motifs. Intermolecular N—HO and O—HO hydrogen bonds involving also the water molecule and weak intermolecular C—HOwater interactions link the molecules into an infinite one-dimensional ribbon structure extending along the b axis. The known (2S) absolute configuration for L-arginine was invoked. Weak intermolecular C—Hπ interactions are also present.
O hydrogen bonds that generate S(6) and S(10) ring motifs. Intermolecular N—HO and O—HO hydrogen bonds involving also the water molecule and weak intermolecular C—HOwater interactions link the molecules into an infinite one-dimensional ribbon structure extending along the b axis. The known (2S) absolute configuration for L-arginine was invoked. Weak intermolecular C—Hπ interactions are also present.
