Acid-Catalysed Dimerization of exo-2-Arylbicyclo[2,2,1]heptan-endo-2-ols

1979 ◽  
Vol 32 (1) ◽  
pp. 167 ◽  
Author(s):  
JM Coxon ◽  
WT Robinson ◽  
PJ Steel
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Perchloric Acid ◽  
Diffraction Data ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray

This paper discusses the reactions of exo-2-arylbicyclo[2,2,1]heptan-endo-2-ols with concentrated perchloric acid which afford the dimers (1RS,2SR,4SR,2'RS,4'SR,7'SR,8'RS)-7'-(aryl)spiro[bicyclo-[2,2,l]heptane-2,9'-tetracyclo[8,4,0,02,7,04,8]tetradeca-10',12,14'-triene] and (1RS,2SR,4SR,1'SR,- 2'RS,10'RS,11'RS)-2-(aryl)spiro[bicyclo[2,2,1]heptane-2,9' tetracyclo[9,2,1,02,10,03,8]tetradeca- 3'5',7'-triene]. The crystal structure of (1RS,2SR,4SA,1'SR,2'RS,10'RS,11'RS)-5'-chloro-2'-(4~'-chlorophenyl)spiro[bicyclo[2,2,1]heptane-2,9'-tetracyclo[9,2,1,02,10,03,8]tetradeca-3',5',7'-triene], determined from X-ray diffraction data and refined by least-squares to a residual of R 0.137 (3715 observed reflections), is reported. The crystals are monoclinic, P21/c, with two molecules in the asymmetric unit; a 10.062(1), b 19.004(2), c 21.539(2)� β 96.42(1)�, Z 8.

Crystal structure of cis-Tetracarbonylbis(chloromercury)iron

1976 ◽  
Vol 29 (9) ◽  
pp. 1905 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
SB Wild
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Data ◽  
Title Compound ◽  
Direct Methods ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound has been determined by direct methods from X-ray diffraction data and refined by least squares to a residual of 0.071 for 2647 'observed' reflections. Crystals are monoclinic, C2/c, a = 36.81(1), b = 11.181(2), c = 20.369(5) �, β = 95.28(3)�, Z = 32. There are four independent molecules in the asymmetric unit, all with the cis disposition of ligands (<Fe-Hg), 2.498 �; <Hg-Fe-Hg), 80.9�); in one of the molecules one of the carbonyl sites is occupied by a more substantial moiety, possibly a result of partial occupancy of HgCl as a result of disorder or decomposition.

scholarly journals Crystal structure refinement of magnesium zinc divanadate, MgZnV2O7, from powder X-ray diffraction data

2021 ◽  
Vol 77 (6) ◽  
pp. 588-591
Author(s):  
Stephanie J. Hong ◽  
Jun Li ◽  
Mas A. Subramanian
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Structure Refinement ◽  
Atomic Ratio ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Wyckoff Position ◽  
Distorted Trigonal Bipyramidal

The crystal structure of magnesium zinc divanadate, MgZnV2O7, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with Mn0.6Zn1.4V2O7 (C2/m; Z = 6) and is related to the crystal structure of thortveitite. The asymmetric unit contains two metal sites with statistically distributed magnesium and zinc atoms with the atomic ratio close to 1:1. One (Mg/Zn) metal site (M1) is located on Wyckoff position 8j and the other (M2) on 4h. Three V sites (all on 4i), and eight O (three 8j, four 4i, and one 2b) sites complete the asymmetric unit. The structure is an alternate stacking of V2O7 layers and (Mg/Zn) atom layers along [20\overline{1}]. It is distinct from other related structures in that each V2O7 layer consists of two groups: a V2O7 dimer and a V4O14 tetramer. Mixed-occupied M1 and M2 are coordinated by oxygen atoms in distorted trigonal bipyramidal and octahedral sites, respectively.

scholarly journals Diterbium heptanickel: a crystal structure redetermination

2014 ◽  
Vol 70 (8) ◽  
pp. i42-i42
Author(s):  
Volodymyr Levytskyy ◽  
Volodymyr Babizhetskyy ◽  
Bohdan Kotur ◽  
Volodymyr Smetana
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Title Compound ◽  
Stoichiometric Composition ◽  
Structure Type ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Coordination Polyhedra ◽  
X Ray ◽  
Anisotropic Displacement Parameters

The crystal structure of the title compound, Tb2Ni7, was redetermined from single-crystal X-ray diffraction data. In comparison with previous studies based on powder X-ray diffraction data [Lemaireet al.(1967).C. R. Acad. Sci. Ser. B,265, 1280–1282; Lemaire & Paccard (1969).Bull. Soc. Fr. Mineral. Cristallogr.92, 9–16; Buschow & van der Goot (1970).J. Less-Common Met.22, 419–428], the present redetermination affords refined coordinates and anisotropic displacement parameters for all atoms. A partial occupation for one Tb atom results in the non-stoichiometric composition Tb1.962 (4)Ni7. The title compound adopts the Ce2Ni7structure type and can also be derived from the CaCu5structure type as an intergrowth structure. The asymmetric unit contains two Tb sites (both site symmetries 3m.) and five Ni sites (.m.,mm2, 3m., 3m., -3m.). The two different coordination polyhedra of Tb are a Frank–Kasper polyhedron formed by four Tb and 12 Ni atoms and a pseudo Frank–Kasper polyhedron formed by two Tb and 18 Ni atoms. The four different coordination polyhedra of Ni are Frank–Kasper icosahedra formed by five Tb and seven Ni atoms, four Tb and eight Ni atoms, three Tb and nine Ni atoms, and six Tb and six Ni atoms, respectively.

Crystal structure of Tris(ethane-1,2-diamine)nickel(II) diperchlorate monohydrate

1978 ◽  
Vol 31 (2) ◽  
pp. 415 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
AC Willis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Structure Determination ◽  
Title Compound ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Very High

The crystal structure of the title compound, [Ni(en)3] (ClO4)2,H2O, has been determined from single-crystal X-ray diffraction data at 295(1) K and refined by least squares to a residual of 0.093 for 1400 'observed' reflections. Crystals are orthorhombic, P bca, a 17.043(7), b 15.922(6), c 13.496(5) Ǻ, Z 8. The precision of the structure determination is adversely affected by very high perchlorate thermal motion. <Ni-N> is 2.13 Ǻ.

The crystal structure of galeite, Na15(SO4)5F4Cl

1975 ◽  
Vol 40 (312) ◽  
pp. 357-361 ◽  
Author(s):  
L. Fanfani ◽  
A. Nunzi ◽  
P. F. Zanazzi ◽  
A. R. Zanzari
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Three Dimensional ◽  
Thermal Parameters ◽  
X Ray Diffraction ◽  
Cell Content ◽  
X Ray ◽  
Structure Factors

SummaryThe crystal structure of galeite from Searles Lake (California) has been determined by means of X-ray diffraction data on a single crystal. A possible structure was derived from that of schairerite on the basis of chemical and lattice analogies and was confirmed by comparison of the observed diffractometric structure factors with the calculated ones. The refinement was performed by least-squares methods employing isotropic thermal parameters and assuming that atoms related by translational pseudosymmetry exhibit equal thermal parameters. The final R value is 0·09. The cell content is 3[Na15(SO4)5F4Cl]; the space group is P31m The lattice dimensions are a 12·197(4)Å, c 13·955(10) Å The marked subcell has P3m1 symmetry and a 7·042Å, c 13·955 Å. The crystal structure of galeite consists of a three-dimensional framework, formed by coordination octahedra around Na+ ions, including tetrahedral holes with sulphur atoms at the centres. The three-dimensional framework can be considered built up by five octahedral sheets (seven sheets can be recognized in schairerite and six in sulphohalite). The very close analogies occurring in the structures of galeite and schairerite are discussed.

scholarly journals Crystal structure of calcium perchlorate anhydrate, Ca(ClO4)2, from laboratory powder X-ray diffraction data

2018 ◽  
Vol 74 (4) ◽  
pp. 514-517 ◽  
Author(s):  
Dongmin Lee ◽  
Hyeri Bu ◽  
Dohwan Kim ◽  
Jooeun Hyoung ◽  
Seung-Tae Hong
Keyword(s):  
Crystal Structure ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Powder Diffraction Data ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Wyckoff Position ◽  
Hydrated Calcium

The crystal structure of calcium perchlorate anhydrate was determined from laboratory X-ray powder diffraction data. The title compound was obtained by heating hydrated calcium perchlorate [Ca(ClO4)2·xH2O] at 623 K in air for 12 h. It crystallizes in the orthorhombic space group Pbca and is isotypic with Ca(AlD4)2. The asymmetric unit contains one Ca, two Cl and eight O sites, all on general sites (Wyckoff position 8c). The crystal structure consists of isolated ClO4 − tetrahedra and Ca2+ cations. The Ca2+ cation is coordinated by eight O atoms of eight symmetry-related ClO4 − tetrahedra within a distorted square-antiprismatic environment.

Crystal structure of trans-chlorobis(ethane-l,2-diamine)sulfitocobalt(III) monohydrate

1980 ◽  
Vol 33 (2) ◽  
pp. 419 ◽  
Author(s):  
CL Raston ◽  
AH White ◽  
JK Yandell
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Independent Molecules

The crystal structure of the title compound, [Co(en)2ClSO3],H2O (en = ethane-1,2-diamine), has been determined by single-crystal X-ray diffraction methods at 295(1) K and refined by least squares to a residual of 0.050 for 3252 'observed' reflections. Crystals are monoclinic, P21/c, a 9.862(4), b 15.897(8), c 16.936(7) Ǻ, β 117.44(4)°, Z 8. The two independent molecules in the asymmetric unit are pseudosymmetrically related. (Co-S) is 2.204 Ǻ, while (Co-Cl) is the longest six-coordinate cobalt(III)-chloride distance observed, being 2.377 Ǻ.

Crystal structure of sodium trans-bis(ethane-1,2-diamine)disulfitocobaltate(III) trihydrate

1980 ◽  
Vol 33 (3) ◽  
pp. 665 ◽  
Author(s):  
GDRCL Fallon ◽  
AH White ◽  
JK Yandell
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Title Compound ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray

The crystal structure of the title compound, Na[Co(en)2(SO3)2],3H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.068 for 1890 'observed' reflections. Crystals are monoclinic, P21/c, a 8.481(3), b 13.661(6), c 13.715(6) Ǻ, β 106.91(3)°, Z 4. The asymmetric unit of the structure contains two independent anions, each located about a crystallographic centre of symmetry. (Co-S) is 2.267 Ǻ, the longest Co-S distance so far reported in cobalt(III)/sulfite complexes.

scholarly journals Crystal structure of strontium perchlorate anhydrate, Sr(ClO4)2, from laboratory powder X-ray diffraction data

2019 ◽  
Vol 75 (4) ◽  
pp. 447-450
Author(s):  
Jooeun Hyoung ◽  
Hyeon Woo Lee ◽  
So Jin Kim ◽  
Hong Rim Shin ◽  
Seung-Tae Hong
Keyword(s):  
Crystal Structure ◽  
Diffraction Data ◽  
Bond Valence ◽  
Structure Model ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Wyckoff Position

The crystal structure of strontium perchlorate anhydrate, Sr(ClO4)2, was determined and refined from laboratory powder X-ray diffraction data. The material was obtained by dehydration of Sr(ClO4)2·3H2O at 523 K for two weeks. It crystallizes in the orthorhombic space group Pbca and is isotypic with Ca(AlD4)2 and Ca(ClO4)2. The asymmetric unit contains one Sr, two Cl and eight O sites, all on general positions (Wyckoff position 8c). The crystal structure consists of Sr2+ cations and isolated ClO4 − tetrahedra. The Sr2+ cation is coordinated by eight O atoms from eight ClO4 − tetrahedra. The validity of the crystal structure model for Sr(ClO4)2 anhydrate was confirmed by the bond valence method.

Crystal structure of (S*S*)-5-(1′-aminoethyl)-4,5-dihydro-3,5-diphenylisoxazole

1989 ◽  
Vol 189 (3-4) ◽  
Author(s):  
Ridha Ben Cheikh ◽  
Ahmed Kallel
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Diffraction Data ◽  
Title Compound ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
X Ray ◽  
Compound C

AbstractCrystals of the title compound, CAtomic positions have been determined by direct methods from single crystal X-ray diffraction data and refined by least squares to

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