Conformations of Bridged Diphenyls. XII. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrobenzyl)-1,3,5-trimethyIbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2121-2126 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
R Factor ◽  
Integrated Intensities

The crystal structure of 2-(4′-carbomethoxy-2′-nitrobenzyl)-1,3,5-trimethylbenzene, C18HI9-N04, has been determined by X-ray diffraction. The crystals are triclinic, a = 9.534(5), b = 11.887(7), c = 7.431(6) Å, α = 101.62(3), β = 97.25(3), γ = 88.61(3)°, [Formula: see text] with Z = 2. The integrated intensities of 3789 independent reflections were measured on a four circle diffractometer; 2448 reflections were used in a full-matrix refinement to a least-squares residual of 0.067 and a conventional R factor of 0.055.The molecule is in the skew-nitro-distal conformation. The angle between the di-ortho-substituted ring and the central C—CH2—C plane is 87.6° and the angle between the nitro-substituted ring and the C—CH2—C plane is 2.2°.

Conformations of Bridged Diphenyls. VIII. Crystal Structure of 2-(2′,6′-Dinitrophenoxy)-t-butyIbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2093-2101 ◽  
Author(s):  
Kapil Gurtu ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Steric Effects ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Independent Molecules ◽  
Integrated Intensities

The crystal structure of 2-(2′,6′-dinitrophenoxy)-t-butylbenzene, C16HI5N2O5, has been determined by X-ray diffraction. The crystals are monoclinic, space group P21/c: a = 13.949(9), b = 9.652(6), c = 23.806(12) Å, β = 93.82(5), Z = 8. The integrated intensities of 6811 reflections were recorded with a four circle automated diffractometer at 20 °C; 3334 of these reflections were used in the refinement of the structure to a least-squares weighted residual of 0.057 and a traditional R factor of 0.057.The two crystallographically independent molecules both have the skew-t-butyl-distal conformation, suggesting that the steric effects of the two ortho-nitro groups play a greater role in determining the conformation than does conjugation with the bridging oxygen atom.

Conformations of bridged diphenyls. XV. Crystal structure of (4′-carbomethoxy-2′-nitrophenoxy)benzene and the effect of intramolecular interactions in nitro substituents

1980 ◽  
Vol 58 (7) ◽  
pp. 658-663 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Phenyl Ring ◽  
Intramolecular Interactions ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Integrated Intensities ◽  
Torsional Angles

The structure of (4′-carbomethoxy-2′-nitrophenoxy)benzene, C14H11NO5, has been determined by X-ray diffraction. The crystals are monoclinic, a = 8.880(7), b = 9.792(4), c = 14.820(5), β = 90.07(5), P21/c with Z = 4. The integrated intensities of 2966 independent reflections were measured on a four-circle diffractometer, 2072 of which were used in the refinement to give a final least-squares weighted residual of 0.062 and a conventional R factor of 0.086. The absence of ortho substituents on one ring of the molecule allows it to adopt the twist-nitro-distal conformation. The lengths of the bonds from the unsubstituted ring and the substituted ring to the bridging oxygen atom are 1.409(3) and 1.353(3) Å respectively. The torsional angles about those bonds are 54.6° and 16.5°. The angle subtended at the bridging oxygen atom is 120.0(3)°.The unusual thermal ellipsoids associated with one of the nitro oxygen atoms of this structure and with a nitro oxygen atom of three related structures occur when the nitro substituent is nearly coplanar with the phenyl ring on which it is substituted and also has a neighbouring substituent or bridging group. The unusual thermal ellipsoids then result from repulsive exchange forces.

Conformations of bridged diphenyls. XIV. Crystal structure of 2-(4′-carbomethoxy-2′ aminophenoxy)-1,3,5-trimethylbenzene and endocylic angles in bridged diphenyls

1979 ◽  
Vol 57 (20) ◽  
pp. 2767-2774 ◽  
Author(s):  
Ramanathan Gopal ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ring Carbon ◽  
R Factor ◽  
Integrated Intensities ◽  
Torsional Angles

The structure of 2-(4′-carbomethoxy-2′-aminophenoxy)-1,3,5-trimethylbenzene, C17H19NO3, has been determined by X-ray diffraction. The crystals are monoclinic, a = 23.895(9), b = 7.821(4), c = 16.641(8) Å, β = 99.26(3), C2/c, Z = 8. The integrated intensities of 3540 independent reflections were measured on a four-circle diffractometer. A total of 2403 of these reflections was used in the refinement to give a final least-squares weighted residual of 0.069 and a conventional R factor of 0.096. The molecule adopts the skew-amino-distal conformation as does the analogous ortho-nitro-substituted compound. The lengths of the bonds from the amino substituted ring and the mesityl ring are 1.404(3) and 1.376(4) Å respectively and the torsional angles about those bonds are ±5.8 and [Formula: see text]. The angle subtended at the bridging oxygen atom is 120.1°. Variations in the endocyclic angles subtended at substituted ring carbon atoms in this and other bridged diphenyls may be understood in terms of a combination of hybridization effects, and the spatial requirements of the bonds to substituents.

scholarly journals Conformations of Bridged Diphenyls. XIII. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrobenzoyl)-1,3,5-trimethylbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2127-2132 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Carbon Atom ◽  
Least Squares ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bond Lengths ◽  
R Factor ◽  
Integrated Intensities

The structure of 2-(4′-carbomethoxy-2′-nitrobenzoyl)-1,3,5-trimethylbenzene, C18H17N05, has been determined by X-ray diffraction. The crystals are triclinic, a = 10.266(5), b = 7.672(5), c = 11.975(8) Å, α = 105.11(3), β = 100.08(3), γ = 111.50(3)°, [Formula: see text] with Z = 2. The integrated intensities of 3732 independent reflections were measured on a four circle diffractometer; 2784 of these reflections were used in the refinement to give a final least-squares weighted residual of 0.046 and a conventional R factor of 0.053.The molecule adopts the twist-nitro-proximal conformation similar to the conformation in the corresponding sulfoxide and sulfone. The angle subtended at the bridging carbon atom is 118.5(2)° and its bond lengths to phenyl carbon atoms are 1.502(2) and 1.503(2) Å.

The molecular and crystal structure of trans-dichloro(dimethylformamide) (2,6-lutidine)platinum(II)

1980 ◽  
Vol 58 (2) ◽  
pp. 97-101 ◽  
Author(s):  
F. D. Rochon ◽  
P. C. Kong ◽  
R. Melanson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Pyridine Derivative ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
R Factor ◽  
Square Planar

The crystal structure of trans-[Pt(DMF)(2,6-lutidine)Cl2] has been determined by X-ray diffraction. The crystals are orthorhombic, space group Pbca, with a = 11.612(13), b = 26.504(33), c = 9.271(9) Å, and Z = 8. The structure was refined by full matrix least-squares analysis to a conventional R factor of 0.051 and a weighted Rw = 0.044. The coordination around the platinum atom is square planar. The 2,6-lutidine ring is perpendicular to the platinum plane. DMF is bonded to platinum through the oxygen atom. It is planar and makes an angle of 71 ° with the platinum plane. The cis–trans configuration of the [Pt(DMF)(L)Cl2] (L = pyridine derivative) complexes in DMF solution is discussed.

scholarly journals Conformations of Bridged Diphenyls. XI. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrophenylsulfonyl)-1,3,5-trimethylbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2115-2120 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Dihedral Angles ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Integrated Intensities

The crystal structure of 2-(4′-carbomethoxy-2′-nitrophenylsulfonyl)-1,3,5-trimethylbenzene, C17H17NO6S, has been determined by X-ray diffraction. The crystals are triclinic, a = 12.907(13), b = 7.577(5), c = 9.1808(9) Å, α = 105.82(3), β = 112.81(5), γ = 93.97(4)°, [Formula: see text] with Z = 2. The integrated intensities of 3792 independent reflections were measured on a four circle diffractometer and 2985 reflections were used in the refinement to give a least-squares residual of 0.046 and a conventional R factor of 0.057.The molecule shows a twist-nitro-proximal conformation. However, the dihedral angles made by the mesityl ring and the nitro-substituted ring with the central C—S—C plane are dissimilar in contrast to the nearly equal angles found for the similarly substituted sulfinyl compound.

The molecular and crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2

1979 ◽  
Vol 57 (1) ◽  
pp. 57-61 ◽  
Author(s):  
R. Melanson ◽  
F. D. Rochon
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Least Squares ◽  
Platinum Atom ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
R Factor ◽  
Square Planar ◽  
Coordination Plane

The crystal structure of [Pt(diethylenetriamine)(guanosine)](ClO4)2 has been determined by X-ray diffraction. The crystals are orthorhombic, space group P212121, with a = 12.486(6), b = 13.444(7), c = 14.678(11) Å, and Z = 4. The structure was refined by block-diagonal least-squares analysis to a conventional R factor of 0.050 and a weighted Rw = 0.045.The coordination around the platinum atom is square planar. Guanosine is bonded to platinum through N(7). The purine planar ring makes an angle of 62.7° with the platinum coordination plane. The structure is stabilized by hydrogen bonding.

Crystal structure of Tetracyclo[5,3,1,12,6,04,9]dodecane (iceane)

1977 ◽  
Vol 30 (8) ◽  
pp. 1837 ◽  
Author(s):  
DPG Hamon ◽  
CL Raston ◽  
GF Taylor ◽  
JN Varghese ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Rigid Body ◽  
Least Squares ◽  
Title Compound ◽  
Molecular Geometry ◽  
Thermal Motion ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Hexagonal Close Packed

The crystal structure of the title compound, C12H18, has been determined at 295 K by X-ray diffraction and refined by full-matrix least squares to a residual of 0.049 for 216 ?observed? reflections; molecular geometry has been corrected for the effects of thermal motion using a rigid body approximation. Crystals are hexagonal, P63/m, a = 6.582(1), c = 11.843(3) Ǻ, Z = 2, the molecules occupying a hexagonal close- packed array.

Röntgenstrukturbestimmung von AlCl3-Pyridin-Addukten: Der strukturelle Aufbau im trans-Dichlorotetrakis(pyridin)aluminium(III)- Tetrachloroaluminat(III) und im Trichlorotris(pyridin)aluminium(III) / X-ray Diffraction Study of AICl3-Pyridine Adducts: The Crystal Structure of trans-Dichlorotetrakis(pyridine)aluminium(III)tetrachloroaluminat(III) and of Trichlorotris(pyridine)aluminium(III)

1982 ◽  
Vol 37 (10) ◽  
pp. 1312-1315 ◽  
Author(s):  
Peter Pullmann ◽  
Karl Hensen ◽  
Jan W. Bats
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Diffraction Study ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
The Mean

Abstract Crystals of [Al(C5H5N)4Cl2][AlCl4] are orthorhombic, Pna21, Z = 4, a = 18.522(7), b = 15.141(5), c = 9.593(3) Å, V = 2690(2) Å3 , Dc = 1.440 g/cm3 . The structure has been solved from 5968 diffractometer measured intensities and refined by full-matrix least squares to Rw(F) = 0.032. The crystal structure shows the complex to be trans-dichloro-tetrakis(pyridine)aluminium(III) tetrachloroaluminat(III). The mean trans Al-Cl-and trans Al-N-distances in the octahedron are 2.279(3) and 2.070(4) Å, respectively. Crystals of Al(C5H5N)3Cl3 are monoclinic, P21/c, Z = 4, a = 7.261(2), b = 29.961(4), c = 8.624(1) Å, β = 98.12(2)°, V -1857(1) Å3 , DC = 1.326 g/cm3 . The structure has been solved from 4707 diffractometer measured intensities and refined to Rw(F) = 0.028. The crystal structure shows octahedral complexes AlCl3·3 (C5H5N) with trans geometry. The Al-N-distance trans to chlorine (2.096(2) Å) is significantly longer than the two other Al-N-distances (mean 2.072(2) Å).

Ring contraction of 4-substituted 2,6-dichlorophenols. The crystal structure of 2,2,4α,5α-Tetrachloro-1α,3α-dihydroxycyclopentane-1,4-carbolactone

1977 ◽  
Vol 30 (10) ◽  
pp. 2195 ◽  
Author(s):  
RM Christie ◽  
RW Rickards ◽  
KJ Schmalzl ◽  
D Taylor
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Direct Methods ◽  
Major Product ◽  
X Ray Diffraction ◽  
Ring Contraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Counter Data

Alkaline chlorination of the 4-alkyl-2,6-dichlorophenols (2b) and (2c) proceeds through ring contraction and halolactonization to form the 4α- alkyl-2,2,5α-trichloro-1α,3α-dihydroxycyclopentane-1,4-carbolactones (4b) and (4c). Under similar conditions, 2,4,6-trichlorophenol affords the analogous 2,2,4α,5α-tetrachloro-1α,3α-dihydroxycyclopentane-1,4- carbolactone (4a) in low yield, in addition to the Hantzsch acid (3a) as the major product. The acid (3a) upon further treatment undergoes chloro-lactonization to give the lactone (4a). The structures of the lactones (4b) and (4c) follow from spectroscopic comparison with (4a), the structure of which has been established by X-ray diffraction (C6H4Cl4O4 orthorhombic a 13.485(1), b 12.348(1), c 11.371(1) Ǻ, space group Pccn, Z 8, solved by direct methods and refined by block-diagonal and full-matrix least squares to R 0.031, Rw 0.043 for 1313 unique counter data with I/σ(I) ≥ 3.0).

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