The crystal structure of vlodavetsite, AlCa2(SO4)2F2Cl·4H2O

1995 ◽  
Vol 59 (394) ◽  
pp. 159-162 ◽  
Author(s):  
G. L. Starova ◽  
S. K. Filatov ◽  
G. L. Matusevich ◽  
V. S. Fundamensky

AbsractThe crystal structure of vlodavetsite, AlCa2(SO4)2F2Cl·4H2O, has been determined, space group I4/m, a = 6.870(1), c = 13.342(2) Å, Z = 2, Dx = 2.35 g/cm3. The polyhedron cation chains are parallel to [001] and consist of couples of distorted Ca octahedra alternating with one distorted Al octahedron rotated through 24° with respect to the former. The chains are linked by SO4-tetrahedra so that all of the four tetrahedron oxygen atoms take part in coordination of Ca atoms to form a distorted octahedron with Cl and F atoms. The Al coordination polyhedron consists of two F atoms and four oxygen atoms belonging to water molecules. There is a specific interaction via hydrogen bonds between oxygen atoms of SO4-tetrahedra and water molecules.

1989 ◽  
Vol 44 (6) ◽  
pp. 637-640 ◽  
Author(s):  
Karl-Friedrich Tebbe ◽  
Norbert Krauß

The new compound Na[I(CN)2] · 2 H2O can be prepared by addition of iodine to a concentrated aqueous solution of sodium cyanide. It crystallizes in the monoclinic space group P21/c with a = 1044.0(2), b = 480.2(2), c = 730.2(2) pm, β = 95.94(2)° and Z = 2. The crystal structure has been refined to Rf = 0.027 for 692 reflections.The structure may be described as a layer-like package of cations Na+, water molecules and trihalide-analogous anions [I(CN)2]-. The anion is strictly linear at the I atom and nearly linear at the C atoms with φ(I-C-N) = 176.2° and d(I-C) = 231.1, d(C-N) = 110.6 pm. The cation is surrounded by a slightly distorted octahedron of nitrogen and oxygen atoms with d(Na · · ·N) = 263.8, d(Na · · · O) = 242.0, 242.8 pm


1987 ◽  
Vol 42 (8) ◽  
pp. 972-976 ◽  
Author(s):  
Christian Robl

AbstractSingle crystals of EA[Q(NO2)2O4] · 4H2O (EA = Ca. Sr) were grown in aqueous silicagel. Ca2+ has CN 8. It is surrounded by 4 oxygen atoms of two bis-chelating [C6(NO2)2O4]2- ions and 4 water molecules, which form a distorted, bi-capped trigonal prism. Sr2+ is coordinated similarly, with an additional water molecule joining the coordination sphere to yield CN 8+1. Corrugated chains extending along [010] and consisting of EA2+ and nitranilate ions are the main feature of the crystal structure. Adjacent chains are interlinked by hydrogen bonds.


1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.


Author(s):  
Jamila Benabdallah ◽  
Zouaoui Setifi ◽  
Fatima Setifi ◽  
Habib Boughzala ◽  
Abderrahim Titi

In the title compound, [Co(C10H8N2)3](C9H5N4O)2, the tris(2,2′-bipyridine)cobalt(II) dication lies across a twofold rotation axes in the space group C2/c. The N atoms of the three bipyridine ligands form a distorted octahedron around the cobalt ion. All the N atoms of the polynitrile 1,1,3,3-tetracyano-2-ethoxypropenide anions participate in C—H...N hydrogen bonds ensuring crystal cohesion and forming a three-dimensional structure. The structure is further stabilized by C—H...π(cation) and anion...π(cation) interactions.


1977 ◽  
Vol 41 (319) ◽  
pp. 375-383 ◽  
Author(s):  
F. Scordari

SummaryFerrinatrite crystallizes in space group P, with a = 15·566(5), c = 8·69(1) Å, and Z = 6. The crystal structure was solved by three-dimensional Patterson and Fourier syntheses, and refined by least squares employing 2378 independent reflexions to a final R value of 0·068. The iron ions occupy special positions and are surrounded octahedrally by oxygen atoms. Fe3+O6 octahedra and SO4, tetrahedra are linked together to form infinite chains of Fe-O-S linkages in the [0001] direction. These chains are linked to each other by [NaO5(H2O)2] polyhedra and probably by hydrogen bonds. The topology of the arrangement is the same as that of the hypothetical P312 structure proposed by Moore and Araki (1974).


1999 ◽  
Vol 54 (6) ◽  
pp. 747-750 ◽  
Author(s):  
Joachim Pickardt ◽  
Pirka Wischlinski

Crystals o f the complex [K (benzo-18-crown-6][Zn(CN)3] H2O were obtained from a solution o f Zn(CN)2, KCN, and benzo-18-crown-6 in water/methanol. The compound crystallizes in the triclinic space group PI (no. 2),: Z = 2, a = 818,6(5), b = 1236,7(8), c = 1359,6(6) pm, a = 67,02(4), β = 87,38(4), 7 = 75,46(5). Each Zn atom is bonded to one bridging cyanide ion to give chains -Zn(CN)Zn -, and to two terminal CN groups. The N atom of one of the terminal CN groups interacts with a potassium ion o f the [K (benzo-18-crown-6)]+ unit. The coordination spheres of the K ions are completed by water molecules, which in turn form hydrogen bonds to N atoms of terminal CN groups of neighbouring chains, whereby puckered sheets are formed


1975 ◽  
Vol 53 (15) ◽  
pp. 2345-2350 ◽  
Author(s):  
Monique Authier-Martin ◽  
André L. Beauchamp

The title compound belongs to space group P21/c with a = 23.99(1), b = 4.245(2), c = 25.98(1) Å, β = 117.58(7)°, and Z = 8. The structure was solved by the heavy-atom method and refined by block-diagonal least squares on 2589 independent observed reflections. All non-hydrogen atoms were refined anisotropically and some of the hydrogen atoms were located but their parameters were not refined. The final values of R and Rw were 0.042 and 0.047, respectively.The two nonequivalent mercury atoms have very similar environments. Two short Hg—Cl bonds (2.34–2.38 Å) at ∼ 165° define a quasi-molecular HgCl2 unit. Overall octahedral coordination is completed with two chloride ions at 2.76–2.84 Å and two chlorine atoms at 3.19–3.26 Å on neighboring HgCl2 quasi-molecules. HgCl6 octahedra share edges to form twofold ribbons in the b direction. This pattern of octahedra is identical with the onereported for β-NH4HgCl3. The cations are pairs of N(1)-protonated adenine molecules linked by two N(10)—H(10)… N(7) hydrogen bonds and stacked in the b direction. Water molecules act as acceptors in moderately strong hydrogen bonds with acidic protons H(1) and H(9) of adeninium ions. Other generally weaker hydrogen bonds exist between the various parts of the structure.


1967 ◽  
Vol 45 (20) ◽  
pp. 2297-2302 ◽  
Author(s):  
P. K. L. Au ◽  
C. Calvo

Cadmium pyrovanadate crystallizes in the C2/m space group with lattice parameters a = 7.088(5) Å, b = 9.091(5) Å, c = 4.963(5) Å, β = 103°21(5)′, and z = 2. This crystal is an isostructure of the mineral thortveitite and thus the anion consists of a pair of centrosymmetrically related corner-sharing VO4 tetrahedra while the cation resides within a distorted octahedron of oxygen atoms. The anion has a linear V—O—V group, but, as with the isostructural pyrophosphates, the central oxygen atom shows an anomalously high thermal activity. The V—O bond distances are 1.76 Å for the inner bond and 1.70 Å for the terminal bond. The bond angles about the anion and cation are similar to those found for the other analogues of thortveitite.


1983 ◽  
Vol 61 (9) ◽  
pp. 2137-2140 ◽  
Author(s):  
Kottayil I. Varughese ◽  
Maria Przybylska ◽  
Kazimir Sestanj ◽  
Francesco Bellini ◽  
Leslie G. Humber

The crystals of C16H14F3NO3S2 belong to the monoclinic space group P21/c with a = 11.577(1), b = 12.404(1), c = 12.366(1) Å, β = 90.01(1)°, and Z = 4. The structure was solved by MULTAN 78. The parameters were refined by block-diagonal least-squares to a final R of 0.047 for 2679 observed reflections. Of particular interest is an intramolecular attractive interaction between the sulfur and oxygen atoms with an [Formula: see text] distance of 2.879(2) Å, in which oxygen appears to act as an electrophile. Intermolecular hydrogen bonds between the hydroxyl and keto groups join the molecules related through a centre of symmetry into dimers.


2019 ◽  
Author(s):  
Roberto Köferstein

Blue single crystals of Cu[μ3-O3P(CH2)2COOH].2H2O (1) and Cu[(RS)-μ3-O3PCH(C2H5)COOH].3H2O (2) have been prepared in aqueous Cu2+-solutions (pH = 2.5–3.5) containing 3-phosphonopropionic acid (1) and (RS)-2-phosphonobutyric acid (2), respectively. 1: Space group Pbca (no. 61) with a = 812.5(2), b = 919.00(9), c = 2102.3(2) pm. Cu2+ is five-fold coordinated by three oxygen atomsstemming from [O3P(CH2)2COOH]2– anions and two water molecules. The Cu-O bond lengths range from194.0(3) to 231.8(4) pm. The connection between the [O3P(CH2)2COOH]2– anions and the Cu2+ cations yields apolymeric structure with layers parallel to (001). The layers are linked by hydrogen bonds. 2: Space group Pbca(no. 61) with a = 1007.17(14), b = 961.2(3), c = 2180.9(4) pm. The copper cations are surrounded by five oxygen atoms in a square pyramidal fashion with Cu-O bonds between 193.6(4) and 236.9(4) pm. The coordination between [O3PCH(C2H5)COOH]2- and Cu2+ results in infinite puckered layers parallel to (001). The layers are not connected by any hydrogen bonds. Each layer contains both R and S isomers of the [O3PCH(C2H5)COOH]2-dianion. Water molecules not bound to Cu2+ are intercalated between the layers.UV/Vis spectra suggest three d-d transition bands at 743, 892, 1016 nm for 1 and four bands at 741, 838, 957and 1151 nm for 2, respectively. Magnetic measurements suggest a weak antiferromagnetic coupling betweenCu2+ due to a super-superexchange interaction. Thermoanalytical investigations in air show that the compounds are stable up to 95 °C (1) and 65 °C (2), respectively.


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