Search results for "periodic table"

The crystal structure of 3,5-diisopropyl-4-nitropyrazole from X-ray powder diffraction data

2001

The crystal structure of 3,5-diisopropyl-4-nitropyrazole, 3c, has been determined by a Patterson Search method from laboratory X-ray powder diffraction data. The crystal data are: monoclinic symmetry with the unit-cell parameters aa 19:530O5U; ba 6:485O1U and ca 17:937O3U A; ba 100:32O1U8; space group I2/a ,C 9H15N3O2, Za 8, 293 K. After indexing the powder pattern by two methods, the unit-cell parameters found were refined by a least-squares technique. A whole pattern- fitting program was used to extract the integrated intensities. The structure was solved taking a related compound as a search model and the final Rietveld refinement converged to Rwpa 0.1971 and Rpa 0.1437. The structure pr…

rac-Ethyl (2Z)-3-{2-[(Z)-4-ethoxy-4-oxobut-2-en-2-ylamino]cyclohexylamino}but-2-enoate

2011

The asymmetric unit of the title compound, C18H30N2O4, contains two independent molecules. In each molecule, the cyclohexane ring adopts a chair conformation with equatorial orientation of the substituents, and the conformation is stabilized by two intramolecular N—H...O hydrogen bonds, forming rings of S(6) graph-set motif. One ethoxy group and one ethyl group are disordered over two sets of sites with refined occupancy ratios of 0.704 (2):0.296 (2) and 0.505 (3):0.495 (3), respectively. In the crystal, a weak intermolecular C—H...O hydrogen interaction is observed, involving the O atom of the major component of the disordered eth…

N-(3-Methoxypropyl)-1,8-naphthalimide

2003

In the title compound, C16H15NO3, the 1,8-naphthaleno­dicarbox­imide group is nearly planar and, in the naphthal­imide ring system, the characteristic alternating pattern of bond lengths is observed. In the crystal, the mol­ecules are connected by a weak C—H⋯O hydrogen bond and extend in the direction parallel to the b axis.

1,4-Dihydro-1-methyl-4-nitriminopyridine Dihydrate

1998

Molecules of the title compound, C6H7N302.2H20, are almost planar with the NNO2 nitrimino group twisted 8 (1) ° out of the plane of the pyridine ring. The nitrimino group and CsN ring form a conju- gated 7r-electron system. These molecules together with water molecules are arranged in planes, They are con- nected with each other by O--H.-.O, O--H...N and weaker C--H..-O hydrogen bonds. Four water mol- ecules form a planar square (OH..-O--H)2 ring with O-..O distances equal to 2.741 (2) and 2.778(2)A. These rings join pairs of molecular planes into double layers, interacting otherwise by van der Waals forces.

1,5-Dimethyl-2-nitrimino-1,2-dihydropyridine

2006

Methyl­ation of 5-methyl-2-nitramino­pyridine provides the title compound, C7H9N3O2, as the only product. The mol­ecule consists of two planar fragments, viz. an aromatic ring and a nitrimino substituent. The NNO2 group is twisted by 17 (2)° out of the plane of the pyridine ring. Despite a small torsion angle between these fragments, the geometry of the mol­ecule indicates the participation of the π-electrons in the C—N bond. The hydrogen bonds in the crystal structure seem to be too weak to generate any deformations observed in the mol­ecule.

Ab initio study of the internal rotation potential of p-disilanylbenzene and p-(1,1′,2,2′-tetramethyldisilanyl)benzene

1996

Abstract We present a detailed ab initio study of the geometrical structure and torsional potential of p -disilanylbenzene and its methyl derivative p -(1,1′,2,2′-tetramethyldisilanyl)benzene. The geometries of the different conformers have been fully optimized at the Hartree-Fock 3-21G ∗ and 6-31G ∗ levels. In all cases, the most stable conformation corresponds to the conformer in which the phenylene group lies in a plane perpendicular to the four silicon atoms. The torsional potential curves calculated using the 3-21G ∗ and 6-31G ∗ basis sets show similar features. In the case of p -(1,1′,2,2′-tetramethyldisilanyl)benzene the interactions between the hydrogen atoms of phenylene and the me…

ChemInform Abstract: Solution Chemistry of Element 106: Theoretical Predictions of Hydrolysis of Group 6 Cations Mo, W, and Sg.

2001

Die kopplungskonstanten nJ(SnC) und n+1J(SnH) ineinigen verbindungen mit der tetramethyldizinngruppe

1977

Abstract Comparison of data on seven compounds containing the group tetramethylditin shows a variation in the coupling constants depending on the lone pair electrons of the substituents.

Darstellung und Struktur der 1: 1‐Additionsverbindung SbCl 3 ·1,4‐Dithian

1974

Darstellung und Rontgenstrukturanalyse von SbCl3·S2C4H8 werden beschrieben. Die Verbindung kristallisiert orthorhombisch in der Raumgruppe P212121 (Nr. 19) mit a = 7.257, b = 11.618 und c = 12.366 A, Z = 4. Die Struktur ist aufgebaut aus SbCl 3- und S2C4H8-Molekulen. Synthesis and X-ray Structure Determination of SbCl3.S2C4H8 The synthesis of SbCl3·S2C4H8 is described. The compound crystallizes in the space group P212121 (No. 19) with cell constants a = 7.257, b = 11.618 and c = 12.366 A, Z = 4. The structure is built up by molecules of SbCl3 and S2C4H8.

Tetraallylsilane π-Complexation: Synthesis and Structure of [Cu5Cl5(CH2-CH=CH2)4Si]

2009

By alternating-current electrochemical technique, starting from CuCl2·2H2O and tetraallylsilane (TAS), crystals of the π complex [Cu5Cl5(CH2–CH=CH2)4Si] (I) were obtained, FTIR characterized and structurally investigated. The structure of I is monoclinic, space group P21/n, a = 12.292(3), b = 12.083(3), c = 13.356(3) A, β = 90.19(3)°, V = 1983.7(9) A3 [at 100(2) K], Z = 4; R1 = 0.0379, wR2 = 0.1040 for 3583 reflections. The TAS molecule behaves as a tetradentate cross-bridged ligand linking four (Cu5Cl5)∞ fragments through the C=C bonds. The influence of the inorganic part and ligand symmetries combined with their conformational abilities on the overall crystal symmetry is discussed.