Darstellung und Struktur von Dimesitylzinnoxid / Synthesis and Structure of Dimesityltinoxide

1982 ◽  
Vol 37 (10) ◽  
pp. 1316-1321 ◽  
Author(s):  
U. Weber ◽  
N. Pauls ◽  
W. Winter ◽  
H. B. Stegmann

Abstract Trimesityltin bromide reacts with concentrated aqueous ammonia to give trimesityltin hydroxide. This compound eliminates mesitylen and yields dimesityltin oxide. The product was investigated bv 13C NMR, mass spectroscopy and X-ray diffractions. Di-mesityltinoxide crystallizes in the space group P21/w with a = 25.38(1) Å, b = 12.525(5) Å, c= 32.91(1) Å, β= 91.37(3)° and two molecules in the asymmetric unit (Z=8). The R-factor is 0.049 for 4688 symmetry-independent reflections. The trimeric molecules have six-membered tin-oxygen heterocycles in a twist conformation.

1996 ◽  
Vol 51 (9) ◽  
pp. 1240-1244 ◽  
Author(s):  
Heide Kraudelt ◽  
Uwe Schilde ◽  
Heike Hefele ◽  
Eberhard Ludwig ◽  
Erhard Ludwig

By reaction of 1-phenyl-3-methyl-4-benzoyl-pyrazol-5-one with benzoylhydrazine the tridentate diacidic ligand 4-[1-(N′-benzoylhydrazino)-1-phenyl-m ethylidene]-3-m ethyl-lphenyl-1-pyrazol-5-one (H2L) is formed which gives complexes ML2 with tetravalent titanium and vanadium ions. The ligand and its complexes were characterized by mass spectroscopy. The vanadium(IV) complex can be oxidised and reduced electrochemicallv. The chemical bonding in the titanium(IV) complex and in the ligand was studied by IR and 13C NMR spectroscopy.The molecular structure of 4-[1-(N′-benzoylhydrazino)-1-phenyl-methylidenel-3-m ethyl-lphenyl- pyrazol-5-one was determined by X-ray analysis. Crystal data: a = 9.159(3) Å, b = 11.014(4) Å, c = 11.136(5) Å, a = 90.11 (2)°, β = 101.84(3)°, γ = 113.01 (2)°; space group P1̄, Z = 2.


Author(s):  
Fang Lu ◽  
Bei Zhang ◽  
Yong Liu ◽  
Ying Song ◽  
Gangxing Guo ◽  
...  

Phytases are phosphatases that hydrolyze phytates to less phosphorylatedmyo-inositol derivatives and inorganic phosphate. β-Propeller phytases, which are very diverse phytases with improved thermostability that are active at neutral and alkaline pH and have absolute substrate specificity, are ideal substitutes for other commercial phytases. PhyH-DI, a β-propeller phytase fromBacillussp. HJB17, was found to act synergistically with other single-domain phytases and can increase their efficiency in the hydrolysis of phytate. Crystals of native and selenomethionine-substituted PhyH-DI were obtained using the vapour-diffusion method in a condition consisting of 0.2 Msodium chloride, 0.1 MTris pH 8.5, 25%(w/v) PEG 3350 at 289 K. X-ray diffraction data were collected to 3.00 and 2.70 Å resolution, respectively, at 100 K. Native PhyH-DI crystals belonged to space groupC121, with unit-cell parametersa = 156.84,b = 45.54,c = 97.64 Å, α = 90.00, β = 125.86, γ = 90.00°. The asymmetric unit contained two molecules of PhyH-DI, with a corresponding Matthews coefficient of 2.17 Å3 Da−1and a solvent content of 43.26%. Crystals of selenomethionine-substituted PhyH-DI belonged to space groupC2221, with unit-cell parametersa = 94.71,b= 97.03,c= 69.16 Å, α = β = γ = 90.00°. The asymmetric unit contained one molecule of the protein, with a corresponding Matthews coefficient of 2.44 Å3 Da−1and a solvent content of 49.64%. Initial phases for PhyH-DI were obtained from SeMet SAD data sets. These data will be useful for further studies of the structure–function relationship of PhyH-DI.


1975 ◽  
Vol 53 (23) ◽  
pp. 3596-3598 ◽  
Author(s):  
François Brisse ◽  
Aviva Battat ◽  
Jean-Claude Richer ◽  
Pierre Mazerolles ◽  
Alfreda Faucher

1,1-Dimethyl-1-germa (and-1-sila) -6,7-cycloundecanediol (C12H26O2Ge and C12H26O2Si) are isostructural as established by their X-ray powder patterns. The dimensions of the triclinic cells are as follows: for the silicon derivative, a = 10.53, b = 12.45, and c = 12.43 Å, α = 81.5°, β = 67.0°, and γ = 76.3°; for the germanium derivative, a = 10.56, b = 12.50, and c = 12.58 Å, α = 82.1°, β = 67.8°, and γ = 76.1°. If the space group is [Formula: see text] there will be two independent molecules in each asymmetric unit.


1991 ◽  
Vol 46 (3) ◽  
pp. 297-302 ◽  
Author(s):  
Wolfgang Petz ◽  
Frank Weller

The reactions of C(NMe2)4 (1) with Mn2(CO)10 or Co2(CO)8 in THF yield[C(NMe2)3][Co(CO)4] (3) and [C(NMe2)3][Mn(CO)5] (4), respectively. The compounds Co(CO)4NMe2 (5) and Mn(CO)5NMe2 (6) could not be found. With CH2Cl2 4 is quantitatively converted into [C(NMe2)3][Mn(CO)4Cl2] (7) as shown by IR and 13C NMR investigations. 3 and 4 were characterized by an X-ray structure determination. 3: Space group Pnma, Z = 4, a = 7.435(2), b = 10.79(2), c = 20.299(5)Å. 4: Space group C2/c, Z = 4, a = 11.378(2), b = 10.165(1), c = 14.533(1) Å; β = 103.37(1)°. The compounds form independent ions with no bonding interactions between cation and anion; the central CN3 unit of the [C(NMe2)3]+ cation in 3 and 4 is disordered.


1983 ◽  
Vol 38 (3) ◽  
pp. 347-349 ◽  
Author(s):  
Herbert W. Roesky ◽  
Pierre Schäfer ◽  
Mathias Noltemeyer ◽  
George M. Sheldrick

Abstract The six membered ring of composition (CH3)2NCN3S2Cl2 3 a was prepared from N,N-dimethylguanidinhydrochloride and trithiadiazindichloride. 3 a was characterized on the basis of mass, 1H, 13C NMR spectra and X-ray structure analysis. Crystals of 3 a are monoclinic, space group P21/c, with a = 660.3(6), b = 834.5(7), c = 1774.7(15) pm, β = 112.83(6)° and Z = 4. The C2N unit lies approximately in the plane of the [-CNSNSN-] ring, with both Cl atoms on the same side of the ring.


2012 ◽  
Vol 68 (8) ◽  
pp. o2358-o2358 ◽  
Author(s):  
María-Guadalupe Hernández Linares ◽  
Gabriel Guerrero-Luna ◽  
Sylvain Bernès ◽  
Marcos Flores-Alamo ◽  
María A. Fernández-Herrera

Diosgenone [(20S,22R,25R)-spirost-4-en-3-one, C27H40O3] has been proposed as a new therapeutic alternative for the treatment of malaria. The first X-ray structure report for diosgenone was by Piroet al.[(2002).Z. Naturforsch. Teil C,57, 947–950] in the space groupP21(Z′ = 2). We now report a new polymorph in the same space group, with two molecules in the asymmetric unit. Both molecules have similar conformations, characterized by a skewed envelopeAring, which contains the C=C bond conjugated with the ketone functionality at C3. The dimorphism results from a modification of the relative orientation of the molecules in the asymmetric unit: two independent molecules were arranged antiparallel in the Piro report, while they are parallel in the present determination.


1992 ◽  
Vol 70 (3) ◽  
pp. 809-816 ◽  
Author(s):  
Brigitte Duthu ◽  
Karim El Abed ◽  
Douraid Houalla ◽  
Robert Wolf ◽  
Joël Jaud

The sulfuration of the tricyclic organophosphorous dimer 2 leads easily to the dithiotricyclic derivative 3, which has been characterized by 31P, 1H, and 13C NMR, elemental analysis, and mass spectroscopy. Its crystal and molecular structure has been established by X-ray diffraction and compared to that of 2, which was previously determined. The comparative analysis of X-ray diffraction and NMR parameters gives accurate information about the molecular structure of both compounds. A numerical value of the anistropy cone of the P=S double bond is proposed. Keywords: phosphecine, NMR, X-ray, tricycle.


Molecules ◽  
2020 ◽  
Vol 25 (6) ◽  
pp. 1436 ◽  
Author(s):  
Gheorghe Borodi ◽  
Alexandru Turza ◽  
Attila Bende

2α-Methyl-4,5α-dihydrotestosterone 17β-propionate, known as drostanolone propionate or masteron, is a synthetic anabolic-androgenic steroid derived from dihydrotestosterone. The crystal structures of two polymorphs of drostanolone propionate have been determined by single crystal X-ray diffraction and both crystallizes in the monoclinic crystal system. One is belonging to the P21 space group, Z = 2, and has one molecule in the asymmetric unit while the second belongs to the I2 space group, Z = 4, and contains two molecules in the asymmetric unit. Another polymorph has been investigated by an X-ray powder diffraction method and solved by Parallel tempering/Monte Carlo technique and refined with the Rietveld method. This polymorph crystallizes in the orthorhombic P212121 space group, Z = 4 having one molecule in the asymmetric unit. The structural configuration analysis shows that the A, B, and C steroid rings exist as chair geometry, while ring D adopts a C13 distorted envelope configuration in all structures. For all polymorphs, the lattice energy has been computed by CLP (Coulomb-London-Pauli), and tight-binding density functional theory methods. Local electron correlation methods were used to estimate the role of electron correlation in the magnitude of the dimer energies. The nature of the intermolecular interactions has been analyzed by the SAPT0 energy decomposition methods as well as by Hirshfeld surfaces.


1988 ◽  
Vol 43 (3) ◽  
pp. 323-327 ◽  
Author(s):  
H. Schumann ◽  
J. Loebel ◽  
D. van der Helm ◽  
M. B. Hossain

The title compound (1) is obtained as brownish crystals by reaction of HOCl3 with NaC5Me5 in tetrahydrofuran. The structure of 1, which has two slightly different independent molecules per asymmetric unit, has been elucidated by X-ray analysis. The crystals are triclinic with a = 1686.2(8) pm, b = 1816(1) pm, c = 846.5(4) pm, α = 92.02(7)°, β = 92.47(9)°, γ = 63.21(5)°, space group P1̄, D(calcd) = 1.560 g/cm3, and R = 0.0286, for 6219 observed reflections with I > 3σ(I).


1995 ◽  
Vol 73 (9) ◽  
pp. 1520-1525
Author(s):  
Luciano Antolini ◽  
Ugo Folli ◽  
Dario Iarossi ◽  
Adele Mucci ◽  
Silvia Sbardellati ◽  
...  

The crystal structures of the title compounds were determined by single crystal X-ray diffraction techniques. The molecule of the Z isomer, which crystallizes in the monoclinic space group C2/c with Z = 4 in a cell of dimensions a = 14.891 (2), b = 10.780(2), c = 8.769(1) Å, β = 97.47(2)°, V = 1395.7(7) Å3 has crystallographic twofold symmetry. The E form crystallizes in the orthorhombic space group Pbca with a = 11.730(1), b = 6.932(1), c = 16.841(1) Å, V = 1369.4(2) Å3 and Z = 4. Its molecules have crystallographically dictated [Formula: see text] symmetry. In both isomers the phenyl rings are roughly perpendicular to the average ethylene plane. The atoms characterizing this plane show significant deviations from planarity in the Z isomer. Marked bond-angle distortions at the ethene carbons of both structures are observed. The 1H and 13C NMR spectra of the compounds were measured and, particularly in the case of the 1H chemical shifts, fall into two quite separate spectral regions. At low temperature, two conformational isomers, those with different relative orientation of the C—Cl bonds of the phenyl rings, are observed in the spectrum of each compound. Keywords: chlorostilbenes, overcrowded molecules. X-ray structure, conformations, NMR spectroscopy.


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