The crystal and molecular structure of 1,1-bis(diphenylphosphino)-2,2-dimethylhydrazine

1976 ◽  
Vol 54 (5) ◽  
pp. 738-743 ◽  
Author(s):  
J. Brian Faught
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Space Group ◽  
Block Diagonal

The structure of 1,1-bis(diphenylphosphino)-2,2-dimethylhydrazine, [(C6H5)2P]2NN(CH3)2 has been determined crystallographically. The compound crystallizes from n-heptane in the space group P21/c with a = 8.910(1), b = 9.686(1), c = 27.489(4) Å, and β = 102.94(2)° with four molecules per unit cell. The structure was solved from 2669 independent reflections with I > 3σ(I) and refined by block diagonal least squares methods to R = 0.032 and Rω = 0.048. Each diphenylphosphino group is bonded to the same hydrazine nitrogen and the geometry about this nitrogen is nearly planar. The average dimensions of the structure are P—C = 1.828 ± 0.005, P—N = 1.715 ± 0.014, N—N = 1.451, and N—C = 1.457 ± 0.003 Å, [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text].

The crystal and molecular structure of 1α,9β-Dichloro-2,2,10,10-tetramethoxy[2,2](2,6)pyridinophane

1978 ◽  
Vol 31 (9) ◽  
pp. 1953 ◽  
Author(s):  
D Taylor
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Title Compound ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Maximum Deviation ◽  
Asymmetric Unit ◽  
Space Group ◽  
Block Diagonal

Crystals of the title compound, C18H20Cl2N2O4, are monoclinic, a 14.706(1), b 17.168(1), c 7.269(1) Ǻ, β 92.72(1)°, space group P21/c with Z = 4. The structure was solved from diffractometer data by direct methods. Block-diagonal least-squares refinement converged at R 0.037, Rw 0.045 for 2103 reflections with I ≥ 3σ(I) which had been corrected for absorption (μ 34.0 cm-1). The asymmetric unit is comprised of two independent half-molecules, each molecule being centrosymmetric. The pyridine rings are distorted from planarity, with a maximum deviation of 0.10 Ǻ at the nitrogen atoms, as a consequence of the short intramolecular N...N contacts of 2.476(4) and 2.473(5) Ǻ.

Die Kristall- und Molekülstruktur von β -Bromo(2-diäthylaminoäthanolato)kupfer(ll) / The Crystal and Molecular Structure of β-Bromo(2-diethylaminoethanolato)copper(II)

1975 ◽  
Vol 30 (1-2) ◽  
pp. 14-18 ◽  
Author(s):  
R. Mergehenn ◽  
L. Merz ◽  
W. Haase
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
Triclinic Space Group ◽  
Polymeric Structure ◽  
Space Group ◽  
X Ray

The crystal and molecular structure of β-bromo(diethylaminoethanolato)copper(II) has been determined from three dimensional X-ray diffractometer data. The compound crystallizes in the triclinic space group Pï with one dimer in a unit cell of dimensions α=10.180(II), b=7.999(9), c=6.227(7) Å and a=110.69(4), β=103.12(4), γ=73.82(4)[°]. The structure was refined by least-squares methods using 1944 independent reflexions to give a final R-index of 0,05. The molecule consists of dimeric Cu2O2-units with Cu—O distances of 1.900(4) Å and 1.914(4) A, respectively. The dimers are additional bridged by bromines, so that a “polymeric” structure results; Cu—Br distances are 2.357(2) and 3.660(2) A, respectively. The Cu—Cu distances are 3.003(2) (oxygen bridges) and 4.506(2) Å (bromine bridges).

Crystal and molecular structure of CuSiF6•4H2O

1969 ◽  
Vol 47 (20) ◽  
pp. 3859-3861 ◽  
Author(s):  
M. J. R. Clark ◽  
J. E. Fleming ◽  
H. Lynton
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Fluorine Atom ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Space Group ◽  
Anisotropic Temperature ◽  
Cell Dimensions ◽  
Final Agreement ◽  
Atomic Parameters

The structure of CuSiF6•4H2O has been shown to consist of chains of [Cu(H2O)4F2] and [SiF6] octahedra linked through a common fluorine atom. The space group is monoclinic P21/a, with cell dimensions a = 7.22 ± 0.01 Å, b = 9.64 ± 0.01 Å, c = 5.36 ± 0.01 Å and β = 105.2 ± 0.3°. There are 2 molecules in the unit cell and the copper and silicon atoms occupy centers of symmetry. Atomic parameters have been obtained from a block diagonal least squares refinement using anisotropic temperature parameters. The final agreement residual for 574 observed reflections is R = 0.083.

The crystal and molecular structure of fluorene

1955 ◽  
Vol 227 (1169) ◽  
pp. 200-214 ◽  
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Experimental Error ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Carbon Skeleton ◽  
Two Dimensional ◽  
Trial And Error ◽  
Orthorhombic System ◽  
Space Group

Fluorene, C 13 H 10 , crystallizes in the orthorhombic system, space group Pnam with four molecules per unit cell. The molecule possesses a plane of symmetry which is parallel to the (001) plane of the crystal. The structure has been determined by trial-and-error methods, followed (i) by a least-squares refinement and (ii) by two-dimensional Fourier syntheses. The results from the two methods of refinement are compared and for (ii) a method is given for systematically correcting for overlapping of atoms in projections. The accuracy of the co-ordinates given by these methods is discussed in detail, and it is concluded that the co-ordinates adopted are correct to ±0.017 Å. The carbon skeleton is planar to within the experimental error and the equation of the plane is y = 1.4375 x + 11.0947.

The Crystal and Molecular Structure of the Adduct Formed by the Reaction of Tributylphosphine and p-Chlorobenzylidenemalononitrile

1973 ◽  
Vol 51 (16) ◽  
pp. 2794-2798 ◽  
Author(s):  
George Ferguson ◽  
Colin Alan Fyfe ◽  
Wayne Clifford Marsh
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Phosphorus Atom ◽  
Negative Charge ◽  
Positive Charge ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Space Group ◽  
Block Diagonal

Crystals of the 1:1 adduct of tributylphosphine with p-chlorobenzylidenemalononitrile are monoclinic, a = 13.719(2), b = 12.557(5), c = 14.229(3) Å, β = 110.59(2)°, Z = 4, space group P21/c. The structure was determined with diffractometer data by direct methods and refined by block-diagonal least-squares calculations to R = 0.10 for 1405 observed reflections. The structure is zwitterionic with the positive charge localized on the phosphorus atom and the negative charge mainly on the terminal —C(CN)2 group.

Structure cristalline et moléculaire du cyclopentadiényle-carbonyle-bistriphénylphosphine-manganèse (benzénate), MnC5H5CO[P(C6H5)3]2•C6H6

1974 ◽  
Vol 52 (7) ◽  
pp. 1140-1146 ◽  
Author(s):  
Claude Barbeau ◽  
Ram Janam Dubey
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Three Dimensional ◽  
Unit Cell ◽  
Electrostatic Repulsion ◽  
Triclinic Space Group ◽  
Space Group ◽  
X Ray ◽  
Distance Formula

The crystal and molecular structure of cyclopentadienylcarbonyl-bis(triphenylphosphine)-manganese(benzenate), MnC5H5CO[P(C6H5)3]2•C6H6, has been obtained from analysis of three dimensional X-ray data obtained with a precession camera. The red, rectangular crystals are triclinic, space group [Formula: see text] and have a unit cell with the following parameters: a = 9.83(2) Å, b = 14.79(1) Å, c = 11.36(2) Å, α = 69.44(8)°, β = 66.48(8)°, γ = 67.57(10)°, and z = 2. The final residual factor is 0.087 for the 4554 independent reflections used in the least squares refinement. The structure consists of individual molecules of Mn(C5H5)CO[P(C6H5)3]2. The distance [Formula: see text] is 2.16(1) Å. The coordinate CO (Mn—C: 1.748(9) Å, C—O: 1.172(11) Å) is perpendicular to the plane of the phosphorous and manganese atoms.The important characteristic is the angle P—Mn—P of 104(1)° (Mn—P: 2.237(3) Å). The angular opening of 14° is considered to be a consequence of an electrostatic repulsion between the two donor P atoms. [Journal translation]

Crystal and Molecular Structure of Dichlorobis(4-methylpyridine)zinc(II), Zn(4-CH3Py)2Cl2

1971 ◽  
Vol 49 (21) ◽  
pp. 3418-3424 ◽  
Author(s):  
H. Lynton ◽  
M. C. Sears
Keyword(s):  
Molecular Structure ◽  
Hydrogen Atom ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Unit Cell ◽  
Thermal Parameters ◽  
Zinc Atom ◽  
Final Agreement ◽  
Atomic Parameters ◽  
Block Diagonal

Crystals of dichlorobis(4-methylpyridine)zinc(II), Zn(4-CH3Py)2Cl2, are monoclinic, space groupP21/c, with a = 14.294(13), b = 7.885(8), c = 13.473(11) Å, β = 100.60(5)° and 4 molecules in the unit cell. The final atomic parameters were obtained from a block-diagonal least squares refinement using anisotropic thermal parameters. The hydrogen atom positions were established but the parameters were not refined. The final agreement residual for 1348 observed reflections is R = 0.043. The zinc atom is tetrahedrally coordinated.

Crystal and molecular structure of dodecamethylcyclohexaphosphazene, (NPMe2)6

1977 ◽  
Vol 55 (17) ◽  
pp. 3118-3123 ◽  
Author(s):  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Direct Methods ◽  
Unit Cell ◽  
Weighted Mean ◽  
Full Matrix ◽  
Space Group ◽  
Bond Lengths ◽  
The Mean

Crystals of dodecamethylcyclohexaphosphazene are triclinic, a = 13.898(1), b = 8.690(1), c = 10.790(1) Å, α = 109.84(1), β = 92.01(1), γ = 106.39(1)°, Z = 2, space group [Formula: see text]. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.034 and Rw of 0.042 for 4217 reflections with I ≥ 3σ(I). The unit cell contains two independent centrosymmetric molecules which are virtually identical. The 12-membered rings have the 'double tub' conformation. Bond lengths not involving hydrogen have been corrected for libration. Weighted mean bond lengths (rms deviations from the mean in parentheses) are: P—N, 1.593(6), C—P, 1.808(4), and C—H, 0.95(6) Å.

The crystal structure of dibutyl-bis(pentamethylenedithiocarbamato)tin(IV)

1986 ◽  
Vol 51 (11) ◽  
pp. 2521-2527 ◽  
Author(s):  
Jan Lokaj ◽  
Eleonóra Kellö ◽  
Viktor Kettmann ◽  
Viktor Vrábel ◽  
Vladimír Rattay
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Coordination Polyhedron ◽  
Crystal And Molecular Structure ◽  
Distorted Octahedron ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

The crystal and molecular structure of SnBu2(pmdtc)2 has been solved by X-ray diffraction methods and refined by a block-diagonal least-squares procedure to R = 0.083 for 895 observed reflections. Monoclinic, space group C2, a = 19.893(6), b = 7.773(8), c = 12.947(8) . 10-10 m, β = 129.07(5)°, Z = 2, C20H38N2S4Sn. Measured and calculated densities are Dm = 1.38(2), Dc = 1.36 Mg m-3. Sn atom, placed on the twofold axes, is coordinated with four S atoms in the distances Sn-S 2.966(6) and 2.476(3) . 10-10 m. Coordination polyhedron is a strongly distorted octahedron. Ligand S2CN is planar.

Reaction of N,N′-dihydroxy-.N,N′-dimethylmethanediamine with phenylboronic acid and the crystal and molecular structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine

1989 ◽  
Vol 67 (11) ◽  
pp. 1959-1963 ◽  
Author(s):  
Wolfgang Kliegel ◽  
Steven J. Rettig ◽  
James Trotter
Keyword(s):  
Molecular Structure ◽  
Crystal Structure ◽  
Least Squares ◽  
Crystal And Molecular Structure ◽  
Phenylboronic Acid ◽  
Direct Methods ◽  
Exact Formula ◽  
Full Matrix ◽  
Space Group ◽  
Hydrogen Bonded

The reaction of N,N′-dihydroxy-N,N′-dimethylmethanediamine with phenylboronic acid leads to the product 1,7-dimethyl-3,5-diphenyl-2,4,6-trioxa-7-aza-1-azonia-3-bora-5-boratabicyclo[3.3.0]octane rather than the expected product 1,5-dimethyl-3-phenyl-1,5-diaza-2,4-dioxa-3-boracyclohexane. The structure of N,N′-dihydroxy-N,N′-dimethylmethanediamine has been determined and is discussed in terms of its reaction with PhB(OH)2. Crystals of N,N′-dihydroxy-N,N′-dimethylmethanediamine are tetragonal, a = 8.5346(3), c = 8.4178(7) Å, Z = 4, space group P421c. The structure was solved by direct methods and was refined by full-matrix least-squares procedures to a final R of 0.036 and Rw of 0.038 for 333 reflections with I ≥ 3σ(I). The structure consists of hydrogen-bonded dimers having exact [Formula: see text] symmetry. Keywords: N,N′-dihydroxy-N,N′-dimethylmethanediamine, crystal structure.

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