scholarly journals Molekül- und Kristallstruktur des 1.5-Dichlor-3.7-bis(trifluormethyl)-4.8-bis(2′.6′-dimethylphenyl)-2.6.9-trioxa- 4.8-diaza-1.5-diborabicyclo [3.3.1] nonadiens / Molecular and Crystal Structure of 1,5-Dichloro-3,7-bis(trifluoromethyl)-4,8-bis(2′,6′-dimethylphenyl)-2,6,9-trioxa-4,8-diaza- 1,5-diborabicyclo[3,3,1 ]nonadiene

1980 ◽  
Vol 35 (12) ◽  
pp. 1499-1502 ◽  
Author(s):  
William Clegg ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick ◽  
Walter Maringgele ◽  
Anton Meller

The structure of the title compound (a = 1185.4, b = 1197.7, c = 1764.8 pm, β = 73.96°, space group P21/c) has been determined from X-ray diffractometer data. The molecule is structurally analogous to the tetraborate ion [B4O7]2-. The eight-membered ring is folded by 104° about the B - B vector. The boron atoms are more strongly bonded to the bridging oxygen [B-O(B) 139 pm] than to the other atoms [B-O(C) 155 pm, B-N 160 pm, B-Cl 182 pm].

1990 ◽  
Vol 43 (12) ◽  
pp. 2083 ◽  
Author(s):  
DC Craig ◽  
VJ James ◽  
JD Stevens

The crystal structure of the title compound (1) has been determined by X-ray diffraction. Crystals of (1) are orthorhombic, space group P21212 with a 11.425(1), b 24.916(1), c 5.8952(3)Ǻ, Z 4. Refinement on 1675 observed reflections measured with Cu Kα radiation converged at R 0.034. The seven- membered ring adopts a boat conformation in which the pseudo plane of symmetry passes through the ring oxygen.


1988 ◽  
Vol 43 (12) ◽  
pp. 1683-1684 ◽  
Author(s):  
Carl D. Habben ◽  
Mathias Noltemeyer

Abstract The title compound, isolated from the reaction of SS-diethyl-N,N'-bistrimethylsilylsulfodiimide and 3.5-dimethyl-1,2,4-trithiadiborolane, crystallizes in space group Pbca with cell constants a - 1218.7(6), b = 1295.8(6), c = 1455.7(9) pm, V = 2.2987 m-3, Z = 8, ϱ = 1.167 Mg m-3. The X-ray structure was refined to R = 0.053


1981 ◽  
Vol 36 (10) ◽  
pp. 1208-1210 ◽  
Author(s):  
Hartmut Köpf ◽  
Joachim Pickardt

Abstract The molecular structure of the bridged [1]-titanocenophane 1,1'-dimethylsilylene titanocene dichloride, (CH3)2Si(C5H4)2TiCl2, has been investigated by an X-ray structure determination. Crystal data: monoclinic, space group C2/c, Z = 4, a = 1332.9(3), 6 = 988.7(3), c = 1068.9(3) pm, β = 113.43(2)°. The results are compared with the structural dimensions of similar compounds: 1,1'-methylene titanocene dichloride, CH2(C5H4)TiCl2, with the unbridged titanocene dichloride, (C5H5)2TiCl2 and the ethylene-bridged compound (CH2)2(C5H4)2TiCl2


1983 ◽  
Vol 36 (11) ◽  
pp. 2333 ◽  
Author(s):  
B Kamenar ◽  
RA Pauptit ◽  
JM Waters

The X-ray crystal structure of 3α,4α:5β,6β-diepoxyandrostan-17-one has been determined. Crystals of the title compound (C19H26O3)are monoclinic, space group P21, with a 9.208(2), b 9.620(4), c 9.312(3) �, β 99.14(2)�, V 814.5 Ǻ3 and Z 2. The structure was solved by direct methods and refined to R 0.039 for 887 observed reflexions. The 3α,4α:5β,6β configuration of the epoxide rings confirms the assignment based on proton n.m.r. studies.


1979 ◽  
Vol 32 (2) ◽  
pp. 301 ◽  
Author(s):  
V Diakiw ◽  
TW Hambley ◽  
DL Kepert ◽  
CL Raston ◽  
AH White

The crystal structure of the title compound, Ca(C6H2N307)2,5H2O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0.049 for 1513 'observed' reflections. Crystals are orthorhombic, Pmab, a 24.169(6), b l0.292(7), c 8.554(2) �, Z 4. The stereochemistry about the calcium has not been observed previously for the system [M(bidentate)2- (unidentate)4]; in the present structure, the calcium is coordinated by a pair of bidentate picrate ligands and the four water molecules in an array in which three of the water molecules occupy a triangular face of a square antiprism, the overall array having m symmetry. The remaining water molecule occupies a lattice site with no close interaction with the other species.


1994 ◽  
Vol 49 (10) ◽  
pp. 1444-1447 ◽  
Author(s):  
Helmut Goesmann ◽  
Dieter Fenske

AbstractSingle crystals of the title compound have been prepared by the reaction of benzonitrile with LiN-(SiMe3)2 in hexane and subsequent evaporation of the solvent. Space group P21/n, Z = 4, structure solution with 7945 observed unique reflections. R = 0.052. Lattice dimensions at -70 °C: a = 1485.2(9); b = 2486.9(11); c = 1568.9(8) pm; β = 91.06(4)°. The compound forms a trimeric ion ensemble in which two of the lithium cations are coordinated by three nitrogen atoms of two phenylamidinate an ions, the other one by four nitrogen atoms of two chelating phenylaminidate anions and in addition by the nitrogen atom of a benzonitrile molecule.


1988 ◽  
Vol 41 (10) ◽  
pp. 1601 ◽  
Author(s):  
AP Arnold ◽  
KJ Cavell ◽  
AJ Edwards ◽  
BF Hoskins ◽  
EJ Peacock

The title compound was prepared by the reaction of sodium hydrogen selenide with 4-chloropent-3-en-2-one. The compound appears unstable with respect to higher oligomers of the SeC (CH3)CHC(CH3)O ( seacac ) unit. X-ray crystallography reveals the unusual structure in which a central 'complexed' selenium atom is coordinated to the two selenium atoms of the seacac ligands which are in their normal cis conformations. The oxygen atoms are uncoordinated and as far removed from the coordination environment of the central selenium atom as possible. Crystals of Se( seacac )2 are orthorhombic with space group P21212, and cell dimension a 9.761(2), b 14.828(3) and c 4.6447(5)Ǻ.


2008 ◽  
Vol 23 (3) ◽  
pp. 241-245
Author(s):  
L. Khemakhem ◽  
A. Kabadou ◽  
A. Ben Salah ◽  
N. Abdelmoula

Polycrystalline BaTi1−x(Zn1/3Nb2/3)xO3 (x=0.025 and 0.9) compounds were synthesized successfully and studied by XRD and dielectric measurements. The effects of the Ti/(Zn,Nb) ratio on the structure and dielectric properties of the compounds were investigated. XRD results indicated that the crystal structure of the x=0.09 compound is cubic perovskite with space group Pm3m and a=4.0095(4) Å. For the x=0.09 compound, a splitting of the (200) peak was observed near 40.2°, indicating that the crystal structure changed from cubic to tetragonal, with space group P4mm, a=4.026(4) Å, and c=4.0091(4) Å. Rietveld refinement of the crystal structures led to final confidence factors Rp=0.0353 and Rp=0.0349 for x=0.025 and 0.9, respectively. Dielectric measurements showed a relaxor behavior present in BaTi0.1(Zn1/3Nb2/3)0.9.


1978 ◽  
Vol 33 (8) ◽  
pp. 838-842 ◽  
Author(s):  
H. J. Keller ◽  
W. Moroni ◽  
D. Nöthe ◽  
M. Scherz ◽  
J. Weiss

Oxidation of 5,10-dihydro-5,10-dimethylphenazine and 5,10-dihydro-5,10-diethyl-phenazine under different reaction conditions leads to several iodine containing solids. The preparation and X-ray structure of two of them, 5,10-dihydro-5,10-dimethyl-phcnaziniumtriiodide (3) and 5,10-dihydro-5,10-diethylphenaziniumtriiodido (4) are reported here.Compound 3 crystallizes in space group P21/n with lattice parameters a = 8.552(6) Å, b= 16.953(2) Å, c- 12.157(9) Å and β= 103.46(2)° with four formula units in the unit cell. The structure was refined to an R-value of 0.046 using 2387 independent reflections. The lattice constains distinct, slightly distorted triiodide ions and bent 5,10-dihydro-5,10-dimethylphenazinium radical cations. Compound 4 crystallizes in the same space group P21/n with lattice parameters a = 8.531(6) Å, b = 8.332(21) Å, c = 13.320(15) Å and β= 94.44(19)° with two formula units in the unit cell. The structure was refined to an R-value of 0.076 using 1195 independent reflections. The lattice contains strictly linear symmetrical triiodide ions and planar centrosymmetrical 5,10-dihydro-5,10-diethyl- phenazinium radical cations.


1977 ◽  
Vol 55 (5) ◽  
pp. 743-748 ◽  
Author(s):  
Jack G. Ballard ◽  
Thomas Birchall ◽  
David R. Slim

The title compound has been prepared by the reaction of SbF5 and SbCl5 in liquid SO2. Raman and Mössbauer spectra have been recorded and its crystal structure determined by three-dimensional X-ray counter measurements. Crystals are monoclinic with a = 12.359(6) Å, b = 16.480(10) Å, c = 9.387(3) Å, β = 103.96(5)°. The structure has been refined in the space group P21/n to a final agreement index R2 of 0.113 for 2415 independent reflections. The structure consists of a cis fluorine-bridged trimer with one of the chlorine atoms 25% substituted by fluorine.


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