scholarly journals Crystal structure of magnesium selenate heptahydrate, MgSeO4·7H2O, from neutron time-of-flight data

2014 ◽  
Vol 70 (9) ◽  
pp. 134-137 ◽  
Author(s):  
A. Dominic Fortes ◽  
Matthias J. Gutmann

MgSeO4·7H2O is isostructural with the analogous sulfate, MgSO4·7H2O, consisting of isolated [Mg(H2O)6]2+octahedra and [SeO4]2−tetrahedra, linked by O—H...O hydrogen bonds, with a single interstitial lattice water molecule. As in the sulfate, the [Mg(H2O)6]2+coordination octahedron is elongated along one axis due to the tetrahedral coordination of the two apical water molecules; these have Mg—O distances of ∼2.10 Å, whereas the remaining four trigonally coordinated water molecules have Mg—O distances of ∼2.05 Å. The mean Se—O bond length is 1.641 Å and is in excellent agreement with other selenates. The unit-cell volume of MgSeO4·7H2O at 10 K is 4.1% larger than that of the sulfate at 2 K, although this is not uniform; the greater part of the expansion is along theaaxis of the crystal.

2012 ◽  
Vol 68 (6) ◽  
pp. m715-m715
Author(s):  
Shan Gao ◽  
Seik Weng Ng

The two independent CdII atoms in the polymeric title compound, [Cd(C10H8N2)(H2O)4](C7H4O6S)·H2O, lie on twofold rotation axes, and each is coordinated by four water molecules and the N atoms of two 4,4′-bipyridine molecules in an octahedral geometry. Bridging gives rise to chains along [101] and [-101]. The 4-hydroxy-3-sulfonatobenzoate dianions are not connected to the CdII atoms, but form hydrogen bonds to the coordinated water molecules as well as the lattice water molecule, generating a three-dimensional network.


1991 ◽  
Vol 46 (12) ◽  
pp. 1635-1640 ◽  
Author(s):  
Thomas Kellersohn ◽  
Robert G. Delaplane ◽  
Ivar Olovsson

Cobalt sulfate heptahydrate (d-14), CoSO4·7D2O, Mr = 294.99, monoclinic, P21/c, a = 1404.8(1), b = 649.41(6), c= 1092.5(2) pm, β = 105.232(8), V = 961.66·106 pm3, Z = 4, Dx = 2.073 Mg· m-3, λ(MoKa) = 71.073 pm, [(sin θ)/λ]max = 0.7035· 10-2 pm-1, μ = 20.26 cm-1, F(000) = 580, T = 298 K, R(F) = 0.0264 for 2339 observed unique reflections. CoSO4·7 D2O is shown to be isotypic to FeSO4· 7 H2O (Melanterite). The deuterated compound is stable at ambient conditions in contrast to the normal hydrate. Its structure is built up by [Co(D2O)6]2+ octahedra, SO42- tetrahedra, and “lattice” water molecules. One water molecule, which is almost exactly trigonally planar coordinated in its average position, exhibits a distinct oxygen disorder. The “lattice” water molecule accepts two strong hydrogen bonds and donates a linear and a bifurcated one. The hydrogen-bond lengths (O···O distances) are in the range 271-302 pm.


2015 ◽  
Vol 71 (9) ◽  
pp. 1105-1108 ◽  
Author(s):  
Hai Le Thi Hong ◽  
Vinh Nguyen Thi Ngoc ◽  
Da Tran Thi ◽  
Ngan Nguyen Bich ◽  
Luc Van Meervelt

The asymmetric unit of the title compound, [Ni(H2O)6](C11H8NO8S)2·2H2O, features a half-hexaaquanickel(II) complex cation with the NiIIion on an inversion center, one deprotonated 5,6-dihydroxy-3-sulfoquinolin-7-yloxyacetic acid (QOH) molecule appearing in its zwitterionic form and one lattice water molecule. The sulfonate group is disordered over two positions with occupancy factors of 0.655 (5) and 0.345 (5). The hexaaquanickel(II) cation interacts through hydrogen bonding with eightQOHmolecules and two water molecules. The six-membered rings of quinoline show π–π stacking [centroid-to-centroid distances of 3.679 (2) Å and 3.714 (2) Å].


2014 ◽  
Vol 70 (10) ◽  
pp. o1124-o1125
Author(s):  
Joel T. Mague ◽  
Mehmet Akkurt ◽  
Shaaban K. Mohamed ◽  
Alaa A. Hassan ◽  
Mustafa R. Albayati

In the title compound, C23H18BrN3OS·0.5H2O, the bromophenyl, phenyl and phenol rings make dihedral angles of 46.5 (1), 66.78 (8) and 15.4 (2)°, respectively, with the mean squares plane of the thiazolidene ring. In the crystal, the lattice water molecule is hydrogen bonded to the phenol group and makes a weaker O—H...N connection to an inversion-related molecule, forming a ring while weak pairwise C—H...S interactions involving inversion-related molecules form a second ring. Both these motifs result in the formation of two-dimensional networks lying parallel to (10-1).


2014 ◽  
Vol 70 (5) ◽  
pp. m184-m184
Author(s):  
Xiao-Juan Wang ◽  
Yun-Long Feng

The title hydrated complex, [Zn2Cl4(C9H12N4)2]·2H2O, is a discrete dinuclear zinc complex with 1,3-bis(1H-imidazol-1-yl)propane as the bridging ligand. The complex molecule lies about a crystallographic inversion centre. The ZnIIatom exhibits a distorted tetrahedral coordination geometry defined by two imidazole N atoms and two Cl atoms. O—H...Cl hydrogen bonding between the lattice water molecules and the terminal Cl atoms of the molecule lead to a two-dimensional structure extending parallel to (100).


2017 ◽  
Vol 73 (11) ◽  
pp. 1599-1602 ◽  
Author(s):  
Matimon Sangsawang ◽  
Kittipong Chainok ◽  
Nanthawat Wannarit

The title compound, [CdNa2(C8H4O4)2(C3H7NO)(H2O)2]nor [CdNa2(1,3-bdc)2(DMF)(H2O)2]n, is a new CdII–NaIheterobimetallic coordination polymer. The asymmetric unit consists of one CdIIatom, two NaIatoms, two 1,3-bdc ligands, two coordinated water molecules and one coordinated DMF molecule. The CdIIatom exhibits a seven-coordinate geometry, while the NaIatoms can be considered to be pentacoordinate. The metal ions and their symmetry-related equivalents are connectedviachelating–bridging carboxylate groups of the 1,3-bdc ligands to generate a three-dimensional framework. In the crystal, there are classical O—H...O hydrogen bonds involving the coordinated water molecules and the 1,3-bdc carboxylate groups and π–π stacking between the benzene rings of the 1,3-bdc ligands present within the frameworks.


2017 ◽  
Vol 73 (12) ◽  
pp. 1977-1980
Author(s):  
Volodymyr M. Hiiuk ◽  
Diana D. Barakhty ◽  
Sergiu Shova ◽  
Ruslan A. Polunin ◽  
Il'ya A. Gural'skiy

In the title polymeric complex, {[Fe(C12H10N2)2(H2O)4](CH3C6H4SO3)2·2CH3OH}n, the FeIIcation, located on an inversion centre, is coordinated by four water molecules in the equatorial positions and two 1,2-bis(pyridin-4-yl)ethene molecules in the axial positions. This results in a distorted octahedral geometry for the [N2O4] coordination polyhedron. The 1,2-bis(pyridin-4-yl)ethene molecules bridge the FeIIcations, forming polymeric chains running along thea-axis direction. Stabilization of the crystal structure is provided by O—H...O hydrogen bonds; these are formed by coordinated water molecules as donors towards the O atoms of the methanol molecules and tosylate anions as acceptors of protons, leading to the formation of a three-dimensional supramolecular network. Weak C—H...O hydrogen bonds are also observed in the crystal.


Author(s):  
Karilys González Nieves ◽  
Dalice M. Piñero Cruz

The title compound, diaqua[tris(2-aminoethyl)amine]nickel(II) hexaaquanickel(II) bis(sulfate), [Ni(C6H18N4)(H2O)2][Ni(H2O)6](SO4)2 or [Ni(tren)(H2O)2][Ni(H2O)6](SO4)2, consists of two octahedral nickel complexes within the same unit cell. These metal complexes are formed from the reaction of [Ni(H2O)6](SO4) and the ligand tris(2-aminoethyl)amine (tren). The crystals of the title compound are purple, different from those of the starting complex [Ni(H2O)6](SO4), which are turquoise. The reaction was performed both in a 1:1 and 1:2 metal–ligand molar ratio, always yielding the co-precipitation of the two types of crystals. The asymmetric unit of the title compound, which crystallizes in the space group Pnma, consists of two half NiII complexes and a sulfate counter-anion. The mononuclear cationic complex [Ni(tren)(H2O)2]2+ comprises an Ni ion, the tren ligand and two water molecules, while the mononuclear complex [Ni(H2O)6]2+ consists of another Ni ion surrounded by six coordinated water molecules. The [Ni(tren)(H2O)2] and [Ni(H2O)6] subunits are connected to the SO4 2− counter-anions through hydrogen bonding, thus consolidating the crystal structure.


2017 ◽  
Vol 73 (12) ◽  
pp. 1926-1930
Author(s):  
R. Drisya ◽  
U. S. Soumya Mol ◽  
P. R. Satheesh Chandran ◽  
M. Sithambaresan ◽  
M. R. Sudarsankumar

The title compound, {[La2(CH3COO)2(C8H10O4)2(H2O)4]·2H2O}nor [La2(ac)2(e,a-cis-1,4-chdc)2(H2O)4]·2H2O, whereacis acetate and 1,4-chdc is cyclohexane-1,4-dicarboxylate anion, is a binuclear lanthanum(III) complex. Each metal atom is decacoordinated by four O atoms from two distinct 1,4-chdc2−ligands, four O atoms from three acetate groups and two O atoms from coordinated water molecules to form a distorted bicapped square-antiprismatic geometry. Two non-coordinated water molecules are also present in the formula unit. The most remarkable feature of this compound is that it possesses a onlycisconformation for cyclohexane-1,4-dicarboxylic acid, although the raw material consists of a mixture ofcisandtransisomers. The μ3-η2:η2coordination mode of the bridging acetate group and the flexible dicarboxylate fragments of 1,4-chdc2−results in the formation of infinite two-dimensional lanthanide–carboxylate layers within the crystal structure. The directionality of strong intermolecular O—H...O and weak C—H...O interactions provides robustness to the layers, which leads to the construction of a three-dimensional supramolecular network. The crystal studied was refined as a two-component twin.


2014 ◽  
Vol 70 (12) ◽  
pp. 515-518 ◽  
Author(s):  
Erik Hennings ◽  
Horst Schmidt ◽  
Wolfgang Voigt

The formation of different complexes in aqueous solutions is an important step in understanding the behavior of zinc chloride in water. The structure of concentrated ZnCl2solutions is governed by coordination competition of Cl−and H2O around Zn2+. According to the solid–liquid phase diagram, the title compounds were crystallized below room temperature. The structure of ZnCl2·2.5H2O contains Zn2+both in a tetrahedral coordination with Cl−and in an octahedral environment defined by five water molecules and one Cl−shared with the [ZnCl4]2−unit. Thus, these two different types of Zn2+cations form isolated units with composition [Zn2Cl4(H2O)5] (pentaaqua-μ-chlorido-trichloridodizinc). The trihydrate {hexaaquazinc tetrachloridozinc, [Zn(H2O)6][ZnCl4]}, consists of three different Zn2+cations, one of which is tetrahedrally coordinated by four Cl−anions. The two other Zn2+cations are each located on an inversion centre and are octahedrally surrounded by water molecules. The [ZnCl4] tetrahedra and [Zn(H2O)6] octahedra are arranged in alternating rows parallel to [001]. The structure of the 4.5-hydrate {hexaaquazinc tetrachloridozinc trihydrate, [Zn(H2O)6][ZnCl4]·3H2O}, consists of isolated octahedral [Zn(H2O)6] and tetrahedral [ZnCl4] units, as well as additional lattice water molecules. O—H...O hydrogen bonds between the water molecules as donor and ZnCl4tetrahedra and water molecules as acceptor groups leads to the formation of a three-dimensional network in each of the three structures.


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