Synthese und Kristallstruktur von MoCl4(DME) · 15-Krone-5 und MoCl4(DME) (DME = 1,2-Dimethoxyethan) / Synthesis and Crystal Structure of MoCl4(DME) · 15-Crown-5 and MoCl4(DME) (DME = 1,2-Dimethoxyethane)

1991 ◽  
Vol 46 (3) ◽  
pp. 307-314 ◽  
Author(s):  
Evamarie Hey-Hawkins ◽  
Hans Georg von Schnering

NaSi reacts with MoCl5 and 15-crown-5 in toluene with reduction of Mo(V) to Mo(IV). Work-up in DME yields MoCl4(DME)· 15-crown-5 (1). MoCl4(DME) (2) is prepared more conveniently from MoCl5/DME. 1 and 2 were characterized spectroscopically and by X-ray structure determination. Crystal data: 1, space group P212121 (No. 19), Z = 4, 2765 observed independent reflexions, R = 0.026, cell dimensions (110 K): a = 16.292(4), b = 12.884(3), c = 10.452(2) Å. 2, space group I4̄2d (No. 122), Z = 8, 558 observed independent reflexions, R = 0.037, cell dimensions (292 K): a = b = 9.562(2), c = 23.777(6)Å. The MoCl4(DME) molecule of 1 and 2 forms a distorted octahedron. There are four non-coordinating 15-crown-5 molecules present in the unit cell of 1. The UV/VIS spectrum and the magnetic properties of 2 are discussed.

1993 ◽  
Vol 48 (7) ◽  
pp. 1009-1012 ◽  
Author(s):  
Kurt Merzweiler ◽  
Harald Kraus

[{Cp(CO)2Fe}SnCl3] reacts with Na2Se in THF to form the compound [{Cp(CO)2Fe}3ClSn3Se4] 1. 1 crystallizes in the monoclinic space group P21/n with 4 formula units per unit cell. The lattice constants are α = 1435.2(7), b = 1124.4(4), c = 1972.7(12) pm, β = 94.59(4)°. According to the X-ray structure determination 1 contains a bicyclic Sn3Se4 framework.


2017 ◽  
Vol 32 (S1) ◽  
pp. S2-S5 ◽  
Author(s):  
Jacek Podwórny ◽  
Alicja Pawełek ◽  
Jerzy Czechowski

Having synthesised an AlON-bonded ceramic corundum material, Al5O3N3 (15R) polytype coexisting with α-Al2O3 was identified. The sample was prepared from an alumina-rich mixture of Al2O3 and AlN substrates and fired at 1650 °C in a nitrogen atmosphere. Using the X-ray external standard quantitative method, one of the reaction products, α-Al2O3, was quantified. From the remaining substrates the stoichiometric composition of the second phase was calculated. The applied method of crystal structure determination consisted of three stages. In the first stage, the Le Bail method of X-ray pattern decomposition was used for the extraction of Al5O3N3 (15R) diffraction lines from a two-phase diffractogram. The space group and unit-cell dimensions from the isostructural SiAl4O2N4 SiAlON phase, producing the same X-ray pattern, were used as input data. Next, the direct structure determination in real space was applied for initial structural model derivation, which was followed by Rietveld refinement. The solved crystal structure of Al5O3N3 (15R), except the stacking sequence, proved to be closely related to the structure of Al7O3N5 (21R) polytype. The Al5O3N3 (15R) is trigonal with space group R-3m, unit-cell dimensions a0 = 3.0128 Å, c0 = 41.8544 Å, and volume V = 329.00 Å3. The model of Al5O3N3 (15R) polytype structure has positional disordering in one of three (6c) Al sites, which leads to stacking faults in six tetrahedral layers. Every third tetrahedron from LR3 and LR4, LR8 and LR9, LR13 and LR14 layers is rotated by 180°.


2006 ◽  
Vol 21 (3) ◽  
pp. 210-213 ◽  
Author(s):  
Mohamed Chakir ◽  
Abdelaziz El Jazouli ◽  
Jean-Pierre Chaminade

A new Nasicon phosphates series [Na3+xCr2−xCox(PO4)3(0⩽x⩽1)] was synthesized by a coprecipitation method and structurally characterized by powder X-ray diffraction. The selected compound Na3.5Cr1.5Co0.5(PO4)3 (x=0.5) crystallizes in the R3c space group with the following hexagonal unit-cell dimensions: ah=8.7285(3) Å, ch=21.580(2) Å, V=1423.8(1) Å3, and Z=6. This three-dimensional framework is built of PO4 tetrahedra and Cr∕CoO6 octahedra sharing corners. Na atoms occupy totally M(1) sites and partially M(2) sites.


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


1996 ◽  
Vol 11 (4) ◽  
pp. 301-304
Author(s):  
Héctor Novoa de Armas ◽  
Rolando González Hernández ◽  
José Antonio Henao Martínez ◽  
Ramón Poméz Hernández

p-nitrophenol, C6H5NO3, and disophenol, C6H3I2NO3, have been investigated by means of X-ray powder diffraction. The unit cell dimensions were determined from diffractometer methods, using monochromatic CuKα1 radiation, and evaluated by indexing programs. The monoclinic cell found for p-nitrophenol was a=6.159(2) Å, b=8.890(2) Å, c=11.770(2) Å, β=103.04(2)°, Z=4, space group P21 or P2l/m, Dx=1.469 Mg/m3. The monoclinic cell found for disophenol has the dimensions a=8.886(1) Å, b=14.088(2) Å, c=8.521(1) Å, β=91.11(1)°, Z=4, space group P2, P2, Pm or P2/m, Dx=2.438 Mg/m3.


1981 ◽  
Vol 36 (2) ◽  
pp. 135-137 ◽  
Author(s):  
Evamarie Hey ◽  
Ulrich Müller

The crystal structure of [MePh3P]2TiCl6 was determined from X-ray diffraction data and refined to a residual index of R = 0.065. It crystallizes in the space group P2i/n with two formula units per unit cell; the cell dimensions are a - 921, b = 1314, c = 1648 pm and y - 100.87°. The TiCl62- ion occupies an inversion center and has the shape of a slightly distorted octahedron with Ti-Cl distances between 233 and 235 pm.


1977 ◽  
Vol 32 (11) ◽  
pp. 1271-1276 ◽  
Author(s):  
Jochen Ellermann ◽  
Norbert Geheeb ◽  
Gerd Zoubek ◽  
Gerhard Thiele

X-ray investigations of brown crystals, formed as a by-product in the reaction of Co2(CO)8 with (C6H5)2P(CH2)2P(C6H5)2 show the existence of the complexCo2(µ-CO)2(CO)4μ-[(C6H5)2P]2NH.The triclinic unit cell (space group PĪ ) contains two complex molecules and one molecule benzene as a solvate. The ligand (C6H5)2P(CH2)2P(C6H5)2, prepared by literature methods, obviously sometimes contains some [(C6H5)2P]2NH. The compoundCo2(μ-CO)2(CO)4μ-[(C6H5)2P]2NH can also be directly synthesized by the reaction of Co2(CO)8 with [(C6H5)2P]2NH.


1989 ◽  
Vol 44 (9) ◽  
pp. 999-1002 ◽  
Author(s):  
Wolfgang Hiller ◽  
Joachim Strähle ◽  
Alfred Zinn ◽  
Kurt Dehnicke

Ph—C(NSiMe3)2AuCl2 has been prepared by the reaction of N,N,N′-tris(trimethylsilyl)-benzamidine with AuCl3 in CH2Cl2 suspension, forming orange-red crystals, which were characterized by an X-ray structure determination.Space group P21/n, Z = 4, 2358 observed independent reflexions, R = 0.028. Lattice dimensions (20°C): a = 695.9(3); b = 1576.1(3); c = 1830.9(3) pm; β = 94.27(3)°. The compound forms monomeric molecules, in which the gold atom is in a square planar arrangement of the two nitrogen atoms of the benzamidinato chelate (Au—N 201.6(7); 203.3(6) pm) and by two chlorine atoms (Au—Cl 227.9(3); 228.5(2) pm).


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.


1991 ◽  
Vol 46 (8) ◽  
pp. 1011-1014 ◽  
Author(s):  
Dieter Fenske ◽  
Sylvia Magull ◽  
Kurt Dehnicke

[Rb(18-crown-6)]2[Zn(Se4)(Se6)] has been prepared by the reaction of a lithium polyselenide solution in DMF with zinc acetate in the presence of rubidium iodide and 18-crown-6. It forms dark red crystals, which were characterized by FIR spectroscopy as well as by an X-ray structure determination. Space group C2/c, Z = 4, 3012 observed unique reflections, R = 0.073. Lattice dimensions at —50 °C: a = 1963.1(14), b = 1125.9(9), c = 2060.3(16) pm, β = 90.05(3)°. The compound has a complex ionic structure, in which the zinc atom of the anion [Zn(Se4)(Se6)]2- is coordinated tetrahedrally by four selenium atoms of a Se42- and a Se62- unit in five and seven membered rings, respectively. The complex cations [Rb(18-crown-6)]+ have Rb · · · Se contacts of 360.7 and 372.0 pm with selenium atoms of the ZnSe4-ring.


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