A Barium Vanadium(V) Selenite Hydrate, Ba(VO2)2(SeO3)2·H2O: A Novel 3D Polymer of Cross-Linked Sheets with Embedded ···V–O–V··· 21 Helices

2014 ◽  
Vol 67 (12) ◽  
pp. 1878 ◽  
Author(s):  
Kieryn L. Kilminster ◽  
Francis J. Lincoln ◽  
Brian W. Skelton ◽  
Allan H. White

The characterisation, by a single-crystal X-ray study at ~150 K, of brown acicular crystals of barium(ii) bis(dioxovanadium(v)) bis(selenite(iv)) monohydrate, BaSe2V2O10·H2O, obtained as a minor product of the synthesis of the previously reported ‘Ba(VO)2(SeO3)2(HSeO3)2’, is recorded. Crystals are monoclinic, P21/c, a = 10.803(2), b = 5.1126(8), c = 17.905(3) Å, β = 92.048(2)°, V = 988.3(3) Å3, 2456 independent diffractometer reflections refining to R1 = 0.032, wR2 = 0.084. A single BaV2Se2O11H2 formula unit, devoid of crystallographic symmetry, comprises the asymmetric unit of the structure, which is a three-dimensional polymer, with component sheets parallel to the crystallographic b axis, containing pentavalent vanadium atoms, one five-, the other six-coordinate, linked by selenite pyramids.

2020 ◽  
Vol 73 (6) ◽  
pp. 455
Author(s):  
Eric J. Chan ◽  
Jack M. Harrowfield ◽  
Brian W. Skelton ◽  
Alexandre N. Sobolev ◽  
Allan H. White

Single crystal X-ray structural characterisations are reported for adducts of the form [(L-O)Eu(O,O′-dpm)3] obtained by the crystallisation of tris(dipivaloylmethanato)europium(iii) (dpm=[HC(C(tBu).CO)2]−) from an array of dipolar aprotic oxygen-donor solvents L (L=N-methylpyrrolidinone (nmp), trimethylphosphate, (MeO)3PO, (tmp), hexamethylphosphoramide (hmpa), dimethylacetamide (dma), dimethyl sulfoxide (dmso), and the bidentate octamethylpyrophosphoramide (ompa). In all adducts, the resulting arrays contain seven-coordinate metal atoms, which adopt two different isomeric forms of the mono-capped trigonal prismatic stereochemistry, the L=dma and dmso adducts corresponding to one type, nmp and tmp the other. The adduct formed with ompa behaves as a pair of discrete metal environments bridged by the O-ompa-O′ ligand, thus; [(dpm-O,O′)3Eu(O-ompa-O′)Eu(O,O′-dpm)3], and is found in two forms, one in which both Eu environments is of the tmp type, the other of the dmso/dma type. In the hmpa adduct, the asymmetric unit of the structure is a disordered composite of both types. In none of the adducts is there any further solvation beyond coordination of a single L.


2004 ◽  
Vol 59 (8) ◽  
pp. 943-946 ◽  
Author(s):  
Viktor Hlukhyy ◽  
Rainer Pöttgen

AbstractThe hexagonal Laves phase MgIr2 was synthesized from the elements in a sealed tantalum tube in an induction furnace. MgIr2 was investigated by powder and single crystal X-ray data: P63/mmc, a = 516.9(1), c = 838.5(2) pm, wR2 = 0.0771, 135 F2 values, and 11 variable parameters. The magnesium atoms have coordination number (CN) 16 (12 Ir + 4 Mg), while the smaller iridium atoms, Ir1 and Ir2, both have CN 12 (6 Ir + 6 Mg). The Ir-Ir distances within the three-dimensional network of face- and corner-sharing Ir4/2 tetrahedra range from 250 to 267 pm. The magnesium atoms have one shorter (306 pm) and three longer (319 pm) magnesium contacts. The crystal chemistry of MgIr2 is briefly discussed and compared with the other binary Mg-Ir intermetallics.


1979 ◽  
Vol 32 (12) ◽  
pp. 2757 ◽  
Author(s):  
CL Raston ◽  
B Walter ◽  
AH White

The title compound, [C5H6N]+ [Cu2(SCN)3]-, has been prepared and its crystal structure determined by single-crystal X-ray diffraction at 295(1) K. Crystals are monoclinic, Cc, a 11.238(7), b 11.644(4), c 10.020(4)Ǻ, β 102.67(3)°, Z 4, the structure being refined to a residual of 0.037 for the 960 'observed' reflections. The structure comprises a three-dimensional network of copper(I) atoms linked by bridging thiocyanate groups, the pyridinium counterions occupying sites in the network cavities. Both copper atoms are four-coordinate, one having an environment of one nitrogen atom [Cu-N, 1.926(9)Ǻ] and three sulfur atoms [Cu-S, 2.319(3), 2.421(3), 2.448(3)Ǻ], while the other is coordinated by two atoms of each type [Cu-N, 1.935(9), 1.947(10); Cu-S, 2.430(3), 2.493(4) Ǻ].


1969 ◽  
Vol 47 (22) ◽  
pp. 4213-4220 ◽  
Author(s):  
C. Calvo ◽  
N. C. Jayadevan ◽  
C. J. L. Lock

One of the compounds obtained by reacting rhenium(III) chloride with isobutyric acid while exposed to oxygen has been shown by single crystal X-ray diffraction to be tris(μ-i-butyrato)di(chlororhenium(III)) perrhenate. The crystals are monoclinic with lattice parameters a = 8.980(5) Å, b = 17.790(8) Å, c = 15.361(8) Å, and β = 114.4(1)°. The space group is P21/c and there are 4 formula units per cell. A total of 1729 independent reflections were examined and the structure was refined by full three dimensional least squares to an R value of 0.114. Two Re environments are found, one consisting of a dimer unit bridged by three carboxylate groups with a chlorine atom per rhenium and the other as a perrhenate group. This latter group, showing a mean Re—O distance of 1.74 Å, shares an oxygen atom with a Re in the dimer unit, and this Re—O bond length is 2.28 Å long. The structure consists of a packing of chains of alternate dimers and perrhenate groups running parallel to the c axis.


2006 ◽  
Vol 62 (4) ◽  
pp. m721-m723 ◽  
Author(s):  
Inke Jess ◽  
Christian Näther

The asymmetric unit of the title compound [Cu8 ICu2 II(CN)4(NCS)8(C6H8N2)7], consists of six crystallographically independent Cu atoms, four thiocyanate anions and two cyanide anions, as well as four 2,6-dimethylpyrazine ligands. Two of the six Cu atoms and one of the four 2,6-dimethylpyrazine ligands are located on centres of inversion. The ligand on a special position is therefore disordered due to symmetry. Altogether there are two copper(II) and eight copper(I) cations in the formula unit. The copper(II) cations are each coordinated by four N atoms within a slightly distorted square-planar coordination. The copper(I) cations, on the other hand, are coordinated by four ligands or anions within distorted tetrahedra. From this arrangement, a three-dimensional coordination network is formed.


1991 ◽  
Vol 44 (7) ◽  
pp. 919 ◽  
Author(s):  
RD Hart ◽  
BW Skelton ◽  
AH White

The 1 : 1 adducts between the copper(I) halides, CuX , X = Cl , Br, I, and the title ligand, 'triphos', Ph2P(CH2)2P(Ph)(CH2)2PPh2, have been synthesized and characterized by single-crystal X-ray structure determination. The three complexes are isomorphous : monoclinic P21/c, a ≈ 14.5, b ≈ 20.5, c ≈ 24.5 Ǻ, β ≈ 118.5°; the asymmetric unit of each structure is the binuclear [Cu2X2( triphos )2] unit (with one acetonitrile solvate). Residuals were 0.047, 0.049 and 0.065 for 6006, 4832 and 5108 'observed', independent reflections respectively. About each copper atom, the four-coordinate environment comprises a terminal halogen [Cu- Cl,Br,I , 2.305(3), 2.311(2); 2.441(2), 2.443(2); 2.614(2), 2.614(2)Ǻ], two phosphorus atoms (central and distal) from the same ligand , and one distal phosphorus atom from the other ligand.


1997 ◽  
Vol 50 (9) ◽  
pp. 947 ◽  
Author(s):  
Brett A. Cloutt ◽  
Dalius S. Sagatys ◽  
Graham Smith ◽  
Raymond C. Bott

A novel efflorescent complex of bismuth(III) with ethylene glycol has been synthesized, and its structure determined by single-crystal X-ray diffraction and refined to a residual R 0·055 for 1811 observed reflections. Crystals are triclinic, space group P-1, with two dimers forming the asymmetric unit in a cell with dimensions a 8·885(3), b 10·796(4), c 7·586(3) Å, α 93·19(3), β 106·61(3), γ 105·72(3)°. The [Bi2(C2H4O2)3] dimer unit, which comprises two different bismuth centres, one five-, the other six-coordinate, is extended into a stable three-dimensional polymer framework via associations through all three ethane-1,2-diolato(2– ) ligands which are bidentate and, in most cases, bridging. The lattice also contains weakly associated but uncoordinated molecules of hydration which are considered responsible for the crystal instability.


1998 ◽  
Vol 51 (8) ◽  
pp. 723 ◽  
Author(s):  
Jack M. Harrowfield ◽  
Raj Pal Sharma ◽  
Brian W. Skelton ◽  
Allan H. White

Room-temperature single-crystal X-ray studies are recorded for 4-nitrophenoxide (4-np¯) salts, variously hydrated, of the Group 1 metals, M(4-np-).χH2O, for M = Li, Na (redetermination), K (already recorded), Rb and Cs. Li(4-np).3H2O is monoclinic, space group Pc, a 11·359(3), b 7·518(3), c 10·855(4) Å, β 90·56(3)°, Z = 4; conventional R on |F| was 0·056 for No 2098 independent `observed" (I > 3σ(I)) reflections. Na(4-np).2H2O is orthorhombic, Ima2, a 6·888(6), b 19·699(8), c 6·436(8) Å, Z = 4, R 0·031 for No 664. Rb(4-np).H2O is orthorhombic, Pbca, a 11·82(3), b 19·724(7), c 7·199(1) Å, Z = 8, R 0·036 for No 1465. Cs(4-np).3H2O is monoclinic, P 21/c, a 13·337(2), b 12·770(5), c 6·311(2) Å, β 100·56(3)°, Z = 4, R 0·031 for No 2636. Whereas the lithium compound is essentially a discrete mononuclear neutral molecular complex [(4-np-O)Li(OH2)3] with four-coordinate lithium, the other compounds exhibit two- or three-dimensional sheet polymer structures with 4-nitrophenoxide moieties providing O-C6H4-NO2 head-tail connecting motifs between successive metal atoms.


1980 ◽  
Vol 33 (2) ◽  
pp. 431 ◽  
Author(s):  
A Farrand ◽  
AK Gregson ◽  
BW Skelton ◽  
AH White

The crystal structure of the title compound, K2Cu(CO3)2, has been determined by single-crystal X-ray diffraction at 295(1) K, and refined by least squares to a residual of 0.027 for 1441 'observed' reflections. Crystals are orthorhombic, space group Fdd2, a 11.425(3), b 17.658(4), c 6.154(2) A, Z 8. The structure comprises potassium cations embedded in an infinite three-dimensional polymeric anionic array of square-planar coordinated copper atoms with bridging carbonate groups [Cu-O 1.934(2), 1.936(2) Ǻ]. Within the latter, the non- coordinating oxygen-carbon bond is shorter [1.259(3) Ǻ] than the other two [1.303(3), 1.307(2) Ǻ] and the O-C-O angle opposite it is correspondingly reduced to 117.1(2)°. The CO3 plane lies at 83.9° to the CuO4 'plane'.


2015 ◽  
Vol 71 (4) ◽  
pp. 330-337 ◽  
Author(s):  
Sabina Kovač ◽  
Ljiljana Karanović ◽  
Tamara Đorđević

Two isostructural diarsenates, SrZnAs2O7(strontium zinc diarsenate), (I), and BaCuAs2O7[barium copper(II) diarsenate], (II), have been synthesized under hydrothermal conditions and characterized by single-crystal X-ray diffraction. The three-dimensional open-framework crystal structure consists of corner-sharingM2O5(M2 = Zn or Cu) square pyramids and diarsenate (As2O7) groups. Each As2O7group shares its five corners with five differentM2O5square pyramids. The resulting framework delimits two types of tunnels aligned parallel to the [010] and [100] directions where the large divalent nine-coordinatedM1 (M1 = Sr or Ba) cations are located. The geometrical characteristics of theM1O9,M2O5and As2O7groups of known isostructural diarsenates, adopting the general formulaM1IIM2IIAs2O7(M1II= Sr, Ba, Pb;M2II= Mg, Co, Cu, Zn) and crystallizing in the space groupP21/n, are presented and discussed.


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