Crystal structure of Cu3(AsO4)2

1968 ◽  
Vol 46 (6) ◽  
pp. 917-927 ◽  
Author(s):  
Sandra J. Poulsen ◽  
C. Calvo

Cu3(AsO4)2 forms a monoclinic crystal with lattice parameters a = 6.327(5) Å, b = 8.642(5) Å, c = 11.313(5) Å, β = 92.04(4)°, and Z = 4. The space group is P21/c. The two orthoarsenate anions in the unit cell have average AsO bond lengths of 1.68 Å and 1.70 Å with mean deviations of 0.02 Å and 0.01 Å respectively. The three cations are fivefold coordinated to oxygen atoms with mean cation oxygen atom bond lengths of 2.005 Å, 2.053 Å, and 2.017 Å for the three independent cations. The range of bond distances extends from 1.892 Å to 2.362 Å. Only one additional cation oxygen distance of less than 3 Å occurs and this lies at 2.76 Å. The cation polyhedra form sheets parallel to the ab plane by corner and edge sharing of common oxygen atoms. Adjacent sheets are bonded through the long Cu—O bond distance cited above and by the AsO43− anions. Each of the arsenic atoms shares three oxygen atoms with one sheet and one with the adjacent one.

1996 ◽  
Vol 51 (2) ◽  
pp. 277-285
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut

Abstract The synthesis of salts of the type RnSH3-n+MF6- (R = C2H5, i-C3H7; n = 1, 2; M = As, Sb) by protonation of the corresponding thiols and sulfides in the superacid systems HF/MF5 is reported. The salts have been characterized by vibrational and NMR spectroscopic methods. Isopropylsulfonium hexafluoroantimonate is the first known example of a sulfonium salt, for which a SH bond distance has been determined by a crystal structure analysis, i-C3H7SH2+SbF6- crystallizes in the monoclinic space group P21/m with a = 568.0(4), b = 801.1(6), c = 1019.7(8) pm, β = 82.63(6) °, with two formula units per unit cell.


1967 ◽  
Vol 45 (20) ◽  
pp. 2303-2316 ◽  
Author(s):  
J. S. Stephens ◽  
C. Calvo

β-Zn3(PO4)2 crystallizes in the monoclinic space group P 21/c with lattice parameters, a = 9.393(3) Å, b = 9.170(6) Å, c = 8.686(3) Å, β = 125.73(10)°, and Z = 4. The three independent cations are strongly ligated to 4, 5, and 5 oxygen atoms, with average Zn—O bond distances of 1.98 ± 0.09 Å, 2.10 ± 0.10 Å, and 2.08 ± 0.13 Å respectively. In addition there are two longer Zn—O distances of 2.51 Å and 2.55 Å in this structure. The PO4 groups exist as independent, nearly regular tetrahedra, with each oxygen atom ligated to two cations. Unlike the structures found for the α and γ phases of Zn3(PO4)2, which contain ribbons and sheets respectively as the basic cation coordination motif, the structure of β-Zn3(PO4)2 contains interconnected sheets.


1994 ◽  
Vol 49 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Petra Joerg ◽  
Gerhard Pezzei ◽  
Alexander Wolski

Abstract Gd2(SO3)3 • 3 H20 is obtained by passing gaseous SO2 through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Single crystals are obtained by heating to 70(2) °C for 6 days. The compound crystallizes in the triclinic space group P 1 with a = 6.499(6), b = 6.621(3), c = 6.954(3) Å, α = 110.71(5), β = 90.54(3), γ = 106.05(1)° and Z = 1. The two crystallographically different gadolinium atoms are both coordinated by eight oxygen atoms forming distorted square antiprisms. Gd(l) is coordinated by six O atoms of sulfite ligands and two O atoms of water, while Gd(2) is surrounded by seven O atoms of SO3 and one of H2O. Gd-O-bond lengths vary between 2.31(3) and 2.50(3) Å.


1970 ◽  
Vol 48 (6) ◽  
pp. 890-894 ◽  
Author(s):  
C. Calvo ◽  
K. Neelakantan

The crystal structure of Mg2As2O7 has been refined by full matrix least squares procedures using 587 observed reflections. The structure of Mg2As2O7 is of the thortveitite type, as reported by Łukaszewicz, with space group C2/m and unit cell dimensions a = 6.567(2) Å, b = 8.524(4) Å, c = 4.739(1) Å, β = 103.8(1)°, and Z = 2. The As—O—As group in the anion appears to be linear but the central oxygen atom undergoes considerable disorder in the plane perpendicular to this group. The AsO bond distances uncorrected for thermal motion are 1.67 Å for the As—O(—As) bond and 1.66 and 1.65 Å for the terminal As—O bonds. The final R value obtained is 0.088.


Author(s):  
Camacho-Camacho Carlos ◽  
Ortiz-Pastrana Naytzé ◽  
Garza-Ortiz Ariadna ◽  
Rojas-Oviedo Irma

Condensation of 8-hydroxyquinoline-2-carbaldehyde with 2-aminophenol gave the (E)-2-[(2-hydroxyphenylimino)methyl]quinolin-8-ol derivative that reacted with di-n-butyltin oxide with release of H2O to yield the chelate title complex, [Sn2(C4H9)4(C16H10N2O2)2]. The compound crystallizes in the triclinic space groupP-1, with two independent centrosymmetric dimers in the unit cell. Each features a typical pincer-type structure where the dianionic ligand is tetradentate, coordinating to the central tin atom through both phenolate oxygen atoms, as well as through the quinoline and imine N atoms. Each metal atom adopts a distorted pentagonal–bipyramidal SnC2N2O3coordination arising from theN,N′,O,O′-tetradentate deprotonated Schiff base, one bridging phenolate O atom of the neighbouring ligand and two butyl groups in the axial sites.


1984 ◽  
Vol 39 (7) ◽  
pp. 850-854 ◽  
Author(s):  
Dieter Fenske ◽  
Karlheinz Stahl ◽  
Evamarie Hey ◽  
Kurt Dehnicke

Both tungsten compounds are formed by reaction of water and oxygen with the acetylene complex PPh4[WCl5(Ph - C ≡ C - C (Br) = C(Br) -Ph)] in CH2Cl2 solutions, and in the presence of PPh4Cl. PPh4[WOCl4] crystallizes in the tetragonal space group P4/n, with two formula units in the unit cell of dimensions a = b = 1269, c = 760 pm at -110 °C (1416 observed in dependent reflexions, R = 0 .054). The [WOCl4]⊖ ion forms a tetragonal pyramid with the oxygen ligand in axial position and a tungsten -oxygen distance of 168 pm. (PPh4)2 [WOCl5 · 2CH2Cl2 crystallizes in the tricline space group P 1̄, with one formula unit per unit cell with a = 1011, b = 1113, c = 1240 pm, α = 70.3°, β = 79.4°, γ = 80.9° at - 110 °C (3781 observed in dependent reflexions, R = 0 .087). The structure contains [WOCl5]2⊖ an ions where the oxygen atom and the chlorine atom in transposition are disordered. (PPh4)2[ReOCl5] · 2CH2Cl2 is formed by the reaction of ReCl5 with PPh4Cl in the presence of water. The compound is isotypic with the corresponding tungsten complex (space group P 1̄, Z = 1, a = 1006, b = 1109, c = 1239 pm , α = 7 0.5°, β = 79.6°, γ = 80.9° at -110 °C; 5436 observed in dependent reflexions R = 0 .050).


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.


1988 ◽  
Vol 43 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Dieter Fenske ◽  
Eberhard Böhm ◽  
Kurt Dehnicke ◽  
Joachim Strähle

Abstract The title compound has been prepared by the reaction of N-trimethylsilyl-iminotriphenylphos-phorane with copper(II) chloride in boiling CCl4 /C2H5OH, and forms moisture sensitive crystals, which are green in transmittance and black in reflexion. [Me3SiNPPh3 · CuCl2 ] 2 was characterized by its IR spectrum as well as by a crystal structure determination (4197 observed, independent reflexions, R = 0.049). The lattice dimensions are at 20 °C: a = 1102.7. b = 1407.3. c = 1560.2 pm; β = 94.27°; space group P21/n with two formula units in the unit cell. The complex consists of centrosymmetric, dimeric molecules with a planar Cu2 Cl2 ring (Cu-CI bond lengths 229 and 231 pm). A terminally bonded CI atom (Cu-CI = 221 pm) and the N atom of the Me3SiNPPh3 ligand (Cu-N = 198.5 pm) complete the coordination number four of the nearly planar surroundings of the Cu atoms.


1994 ◽  
Vol 49 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Hans-Ulrich Hummel ◽  
Petra Joeg ◽  
Gerhard Pezzei ◽  
Alexander Wolski

Abstract Gd(HSO4)3 is obtained on treatment of Gd2(SO4)3 in conc. H2SO4 in closed vessels at 200 °C. The extremely moisture-sensitive crystals belong to the orthorhombic space group Pbca. Lattice constants are a = 12.080(8), b = 9.574(8), c = 16.513(8)Å and Z = 8. Gadolinium is coordinated by eight oxygen atoms of the hydrogensulfate ligands forming a distorted square antiprism. There are three different HSO4- anions within the structure. One of them is coordinated with two Gd atom s while two HSO4- anions bridge three Gd atoms. The Gd-O bond lengths vary in the range of 2.334(6)-2.423(5)Å .


1970 ◽  
Vol 48 (4) ◽  
pp. 537-543 ◽  
Author(s):  
N. Ch. Panagiotopoulos ◽  
I. D. Brown

The crystal structure of triclinic rubidium dichromate has been determined by single crystal X-ray diffraction. The crystal belongs to space group [Formula: see text] with a = 13.554, b = 7.640, c = 7.735 Å, α = 93.64°, β = 98.52°, γ = 88.80° and has four Rb2Cr2O7 units in the unit cell. The final weighted agreement index after refinement by least-squares analysis is 0.058. The configuration of the dichromate ions is similar to that found in most other dichromate structures (Cr—O (bridging) = 1.78 Å, Cr—O (terminal) = 1.62 Å). The two non-equivalent Cr—O—Cr angles are 123 and 137°. The rubidium ions are surrounded by either 8 or 9 oxygen atoms at distances ranging from 2.86 to 3.31 Å. The structure of triclinic Rb2Cr2O7 is similar, but not identical, to that of triclinic K2Cr2O7.


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