Darstellung und Charakterisierung der Carbosilazane Bis[tris(methylamino)silyl]methan und Bis[tris(phenylamino)silyl]methan/Preparation and Characterization of the Carbosilazanes Bis[tris(methylamino)silyl]methane and B is[tris(phenylamino)silyl]m ethane

1997 ◽  
Vol 52 (6) ◽  
pp. 707-710
Author(s):  
M. Jansen ◽  
S. Bzik
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Crystal Structure Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters

Bis[tris(methylamino)silyl]methane (1) and bis[tris(phenylamino)silyl]methane (2) have been synthesized as potential precursors of porous oxygen-free solids by the reaction of bis(trichlorsilyl)methane with methylamine and with lithiated aniline, respectively. Compound 2 was characterized by a crystal structure analysis. It crystallizes in the monoclinic space group P 21 ,/c with the unit cell parameters a= 10.963(2),b= 17.801(2), c = 17.557(2) Å, β = 97.96(2)° and Z = 4 (R1, = 4,4 %, wR2 = 9,8 %, 5950 independent reflections).

Primäre und sekundäre Ethyl-und i-Propylsulfoniumsalze sowie Kristallstruktur von i-C3H7SH2+SbF6- [1]

1996 ◽  
Vol 51 (2) ◽  
pp. 277-285
Author(s):  
Rolf Minkwitz ◽  
Ulrike Lohmann ◽  
Hans Preut
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Bond Distance ◽  
Crystal Structure Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Spectroscopic Methods ◽  
Sulfonium Salt ◽  
Space Group

Abstract The synthesis of salts of the type RnSH3-n+MF6- (R = C2H5, i-C3H7; n = 1, 2; M = As, Sb) by protonation of the corresponding thiols and sulfides in the superacid systems HF/MF5 is reported. The salts have been characterized by vibrational and NMR spectroscopic methods. Isopropylsulfonium hexafluoroantimonate is the first known example of a sulfonium salt, for which a SH bond distance has been determined by a crystal structure analysis, i-C3H7SH2+SbF6- crystallizes in the monoclinic space group P21/m with a = 568.0(4), b = 801.1(6), c = 1019.7(8) pm, β = 82.63(6) °, with two formula units per unit cell.

The crystal structure of Cu2GeSe3 and the structure-types of the I2-IV-VI3 family of semiconducting compounds

2021 ◽  
Vol 77 (1) ◽  
pp. 158-167
Author(s):  
Analio Dugarte-Dugarte ◽  
Nahum Ramírez Pineda ◽  
Luis Nieves ◽  
José Antonio Henao ◽  
Graciela Díaz de Delgado ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Orthorhombic Space Group ◽  
Initial Report ◽  
Space Group ◽  
Cell Parameters ◽  
Semiconducting Compounds ◽  
Bond Valence Model

Almost 50 years after the initial report, the crystal structure of Cu2GeSe3, a I2-IV-VI3 semiconductor, has been revised using modern single-crystal X-ray diffraction data. The structure of this material can be properly described in the monoclinic space group Cc (No. 9) with unit-cell parameters a = 6.7703 (4) Å, b = 11.8624 (5) Å, c = 6.7705 (4) Å, β = 108.512 (6)°, V = 515.62 (5) Å3, Z = 4, rather than in the orthorhombic space group Imm2 (No. 44) with unit-cell parameters a = 11.860 (3), b = 3.960 (1), c = 5.485 (2) Å, V = 257.61 Å3, Z = 2, as originally proposed [Parthé & Garín (1971). Monatsh. Chem. 102, 1197–1208]. Contrary to what was observed in the orthorhombic structure, the distortions of the tetrahedra in the monoclinic structure are consistent with the distortions expected from considerations derived from the bond valence model. A brief revision of the structures reported for the I2-IV-VI3 family of semiconducting compounds (I: Cu, Ag; IV: Si, Ge, Sn; and VI: S, Se, Te) is also presented.

Molecular and crystal structure of a copper(II) complex of sildenafil

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Akhmatkhodja N. Yunuskhodjayev ◽  
Shokhista F. Iskandarova ◽  
Vahobjon Kh. Sabirov
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Piperazine Ring ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Abstract The crystal structure of a copper(II) complex of protonated sildenafil, CuCl3C22H31N6O4S⋅2H2O was studied by single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P21/n with the unit cell parameters a = 15.4292(2), b = 9.06735(12), c = 21.1752(2) Å, V = 2945.48(7) Å3, Z = 4. The Cu atom is coordinated by the sildenafil ligand via the N2 atom of the pyrazolopyrimidine ring and by three chloride anions. Sildenafil is protonated at the methylated N6 atom of the piperazine ring and it is cation ligand with a 1+ charge.

scholarly journals Purification, crystallization and preliminary X-ray characterization ofBacillus cereusarylamineN-acetyltransferase 3 [(BACCR)NAT3]

2012 ◽  
Vol 68 (2) ◽  
pp. 196-198 ◽  
Author(s):  
Xavier Kubiak ◽  
Benjamin Pluvinage ◽  
Inès Li de la Sierra-Gallay ◽  
Patrick Weber ◽  
Ahmed Haouz ◽  
...  
Keyword(s):  
Bacillus Cereus ◽  
Catalytic Triad ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Metabolizing Enzymes ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

ArylamineN-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization ofBacillus cereusarylamineN-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space groupC121, with unit-cell parametersa= 90.44,b= 44.52,c = 132.98 Å, β = 103.8°.

scholarly journals Chemical Preparation, Crystal Structure Reinvestigation and Vibrational Study of CoNa3P3O10.12H2O and X-ray Characterization of the New Anhydrous Triphosphate CoNa3P3O10

2021 ◽  
Vol 12 (2) ◽  
pp. 2586-2602
Keyword(s):  
Ion Exchange Resin ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Compound A ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

The triphosphate dodecahydrate of cobalt and sodium CoNa3P3O10.12H2O was prepared by the ion exchange resin process. Its structure was studied by X-ray diffraction and determined in the monoclinic space group P121/c1with the unit-cell parameters a = 14.6650(5) Å, b=9.1916(3) Å, c = 15.0239(5) Å, =90.2210(10) °, Z = 4 and V = 2025.13(12) Å3. The thermal dehydration of this compound was performed, leading to an anhydrous new form, CoNa3P3O10, which was characterized by X-ray diffraction. The obtained CoNa3P3O10 crystallized in monoclinic space group P21/n with the unit-cell parameters a=15,3774 Å, b=7,6988 A°, c=14,2832A°, β=92,9115°.The characteristic IR wavenumbers of the P3O105− ions observed in the vibrational spectra were calculated using isotopic substitutions, which confirms the existence of these groups in the studied compound. A comparison between the IR and Raman wavenumbers of CoNa3P3O10.12H2O, CoNa3P3O10 and Na5P3O10.12H2O was performed. A kinetic study was also made for CoNa3P3O10·12H2O.

Synthesis, characterization, and crystal structure of two zinc linear dicarboxylates

2016 ◽  
Vol 31 (3) ◽  
pp. 229-232
Author(s):  
Berenice Torruco Baca ◽  
Luis Felipe del Castillo ◽  
Paula Vera-Cruz ◽  
Rubén A. Toscano ◽  
Joelis Rodríguez-Hernández ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Zinc Adipate

Two different crystalline structures corresponding to a zinc adipate and a zinc succinate were determined combining: X-ray powder and single-crystal diffraction, infrared spectroscopy, thermal analysis, and true densities experiments. The zinc succinate crystal structure was determined by single-crystal X-ray diffraction. This compound crystallizes in the orthorhombic space-group Cccm with unit-cell parameters a = 4.792(1) Å, b = 21.204(6) Å, c = 6.691(2) Å, V = 679.8(3) Å3, and Z = 8. Zinc adipate crystal structure was refined from the laboratory X-ray powder diffraction data by the Rietveld method. It crystallizes in the monoclinic space group P2/c with unit-cell parameters, a = 16.2037(17)Å, b = 4.7810(2)Å, c = 9.2692(6)Å, β = 90.329(3)°, V = 718.07(9) Å3, and Z = 4. The thermal expansion of it was estimated in 5.40 × 10−5 K−1. This contribution is a step on the way to systematize the regularities in the coordination diversity between linear dicarboxylates and transition metal–inorganic buildings units of metal–organic frameworks.

scholarly journals Crystal structure of barley agmatine coumaroyltransferase, an N-acyltransferase from the BAHD superfamily

2020 ◽  
Vol 76 (12) ◽  
pp. 590-596
Author(s):  
Miyo Yamane ◽  
Mihoko Takenoya ◽  
Shunsuke Yajima ◽  
Masayuki Sue
Keyword(s):  
Crystal Structure ◽  
Hordeum Vulgare ◽  
Secondary Metabolites ◽  
Secondary Metabolism ◽  
Structural Information ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters

The enzymes of the BAHD superfamily, a large group of acyl-CoA-dependent acyltransferases in plants, are involved in the biosynthesis of diverse secondary metabolites. While the structures of several O-acyltransferases from the BAHD superfamily, such as hydroxycinnamoyl-CoA shikimate hydroxycinnamoyl transferase, have been elucidated, no structural information on N-acyltransferases is available. Hordeum vulgare agmatine coumaroyltransferase (HvACT) is an N-acyltransferase from the BAHD superfamily and is one of the most important enzymes in the secondary metabolism of barley. Here, an apo-form structure of HvACT is reported as the first structure of an N-acyltransferase from the BAHD superfamily. HvACT crystals diffracted to 1.8 Å resolution and belonged to the monoclinic space group P21, with unit-cell parameters a = 57.6, b = 59.5, c = 73.6 Å, α = 90, β = 91.3 , γ = 90°. Like other known BAHD superfamily structures, HvACT contains two domains that adopt a two-layer αβ-sandwich architecture and a solvent-exposed channel that penetrates the enzyme core.

scholarly journals The crystal structure of alstonite, BaCa(CO3)2: an extraordinary example of ‘hidden’ complex twinning in large single crystals

2020 ◽  
Vol 84 (5) ◽  
pp. 699-704
Author(s):  
Luca Bindi ◽  
Andrew C. Roberts ◽  
Cristian Biagioni
Keyword(s):  
Crystal Structure ◽  
Single Crystals ◽  
Structure Determination ◽  
Unit Cell ◽  
Crystal Structure Determination ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Structure Determinations

AbstractAlstonite, BaCa(CO3)2, is a mineral described almost two centuries ago. It is widespread in Nature and forms magnificent cm-sized crystals. Notwithstanding, its crystal structure was still unknown. Here, we report the crystal-structure determination of the mineral and discuss it in relationship to other polymorphs of BaCa(CO3)2. Alstonite is trigonal, space group P31m, with unit-cell parameters a = 17.4360(6), c = 6.1295(2) Å, V = 1613.80(9) Å3 and Z = 12. The crystal structure was solved and refined to R1 = 0.0727 on the basis of 4515 reflections with Fo > 4σ(Fo) and 195 refined parameters. Alstonite is formed by the alternation, along c, of Ba-dominant and Ca-dominant layers, separated by CO3 groups parallel to {0001}. The main take-home message is to show that not all structure determinations of minerals/compounds can be solved routinely. Some crystals, even large ones displaying excellent diffraction quality, can be twinned in complex ways, thus making their study a crystallographic challenge.

Cyclisierung von Amidoximen mit Oxybis(diphenylboran) / Cyclization of Amidoximes with Oxybis(diphenylborane)

1991 ◽  
Vol 46 (9) ◽  
pp. 1219-1222 ◽  
Author(s):  
Hans Möhrle ◽  
Karin Bluhme-Hensen ◽  
Birgit Middelhauve ◽  
Dietrich Mootz ◽  
Hartmut Wunderlich
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bond ◽  
Structure Analysis ◽  
Heterocyclic Ring ◽  
Crystal Structure Analysis ◽  
Monoclinic Space Group ◽  
Space Group ◽  
Bifurcated Hydrogen Bond ◽  
Boron Heterocycles

Substituted amidoximes when reacted with oxybis(diphenylborane) do not yield ester chelates as main products but boron heterocycles. The compound obtained from p-toluamidoxime was found by crystal structure analysis to be 2-phenyl-4-(4-methylphenyl)-2,3-dihydro-1,3,5,2-oxadiazaborol (9). The conformation of the molecule is determined by angles of 29.1 and 24.4° between the planes of adjacent rings. Except N–O all bonds in the heterocyclic ring contain significant π character. Molecules are linked to chains by a weak bifurcated hydrogen bond. 9 crystallizes with the monoclinic space group P21/c, Ζ = 4, a = 5.574(2), b = 18.274(4), c = 12.754(4) Å, β = 106.41(2)°. Refinement of 227 parameters using 1709 observed reflections converged at R = 0.037.

scholarly journals Crystal Chemistry and High-Temperature Behaviour of Ammonium Phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the Burned Dumps of the Chelyabinsk Coal Basin

Minerals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 486 ◽  
Author(s):  
Andrey A. Zolotarev ◽  
Elena S. Zhitova ◽  
Maria G. Krzhizhanovskaya ◽  
Mikhail A. Rassomakhin ◽  
Vladimir V. Shilovskikh ◽  
...  
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Unit Cell ◽  
X Ray Diffraction ◽  
Coal Basin ◽  
Unit Cell Parameters ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters ◽  
Mineral Phases

The technogenic mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O from the burned dumps of the Chelyabinsk coal basin have been investigated by single-crystal X-ray diffraction, scanning electron microscopy and high-temperature powder X-ray diffraction. The NH4MgCl3·6H2O phase is monoclinic, space group C2/c, unit cell parameters a = 9.3091(9), b = 9.5353(7), c = 13.2941(12) Å, β = 90.089(8)° and V = 1180.05(18) Å3. The crystal structure of NH4MgCl3·6H2O was refined to R1 = 0.078 (wR2 = 0.185) on the basis of 1678 unique reflections. The (NH4)2Fe3+Cl5·H2O phase is orthorhombic, space group Pnma, unit cell parameters a = 13.725(2), b = 9.9365(16), c = 7.0370(11) Å and V = 959.7(3) Å3. The crystal structure of (NH4)2Fe3+Cl5·H2O was refined to R1 = 0.023 (wR2 = 0.066) on the basis of 2256 unique reflections. NH4MgCl3·6H2O is stable up to 90 °C and then transforms to the less hydrated phase isotypic to β-Rb(MnCl3)(H2O)2 (i.e., NH4MgCl3·2H2O), the latter phase being stable up to 150 °C. (NH4)2Fe3+Cl5·H2O is stable up to 120 °C and then transforms to an X-ray amorphous phase. Hydrogen bonds provide an important linkage between the main structural units and play the key role in determining structural stability and physical properties of the studied phases. The mineral phases NH4MgCl3·6H2O and (NH4)2Fe3+Cl5·H2O are isostructural with natural minerals novograblenovite and kremersite, respectively.

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