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.

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.

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°.

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.

Studies of β-Diketone Complexes of Rhenium(V). The Molecular and Crystal Structure of trans-Dichlorobis(pentane-2,4-dionato)rhenium(IV)

1973 ◽  
Vol 51 (13) ◽  
pp. 2073-2076 ◽  
Author(s):  
I. D. Brown ◽  
C. J. L. Lock ◽  
Che'ng Wan
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Molecular And Crystal Structure ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
X Ray ◽  
Bond Lengths ◽  
Dimeric Structure

One of the compounds obtained by reacting acetylacetone with oxoethoxodichlorobis(triphenylphosphine)rhenium(V) has been shown by single crystal X-ray diffraction to be trans-dichlorobis(pentane-2,4-dionato)rhenium(IV). The crystals are triclinic, a = 8.032(4), b = 8.344(6), c = 7.429(6) Å, α = 118.1(2), β = 92.3(2), γ = 55.5(2)°, [Formula: see text], Z = 1. Intensities were measured with a microdensitometer from photographs recorded on an integrating precession camera. Of the 991 measured reflections all were observed and 984 were used in the refinement. The structure was refined by full matrix least squares to an R2 value of 0.0685. The compound was found to be a trans-monomer, in contrast to the dimeric structure claimed to exist in solution. The ligand atoms bonded to rhenium lie almost exactly at the apices of an octahedron and the bond lengths (Re—Cl, 2.326(8); Re—O1, 1.97(1); Re—O2, 2.01(1) Å) are in the range expected.

Crystal Structure of Tetraethylammonium Bromopentacarbonyltungstate(0)

1995 ◽  
Vol 48 (5) ◽  
pp. 1045 ◽  
Author(s):  
T Whyte ◽  
GA Williams
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
X Ray Diffraction ◽  
Full Matrix ◽  
Space Group ◽  
X Ray ◽  
Bond Lengths ◽  
R Value

The crystal structure of tetraethylammonium bromopentacarbonyltungstate (0), [NEt4] [W(CO)5Br], has been determined by single-crystal X-ray diffraction methods at 22�1°C. Crystals are tetragonal, space group P4/n, with a 9.206(2), c 10.484(2) Ǻ, and Z 2. Full-matrix least-squares refinement gave a final R value of 0.034 for 820 independent reflections. The [W(CO)5Br]- anion possesses exact C4v symmetry, with bond lengths W-Br 2.736(1), W-COtrans 1.93(1) and W-COcis 2.034(6) Ǻ.

Conformations of Bridged Diphenyls. IX. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrothiophenyl)-1,3,5-trimethylbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2102-2107 ◽  
Author(s):  
Simon P. N. Van Der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Least Squares ◽  
Sulfur Atom ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Diphenyl Ethers ◽  
Phenyl Rings

The structure of 2-(4′-carbomethoxy-2′-nitrothiophenyl)-1,3,5-trimethylbenzene, C17H17-NO4S, has been determined by X-ray diffraction. The crystals are monoclinic, a = 18.616(15), b = 5.739(8), c = 15.712(14) Å, β = 101.97(3)°, P21/c with Z = 4. The intensities of 3820 independent reflections were measured on a four circle diffractometer; 2825 reflections were used in the refinement of the structure to give a final least-squares weighted residual of 0.059 and a traditional R factor of 0.054. The presence of electron-withdrawing groups on one of the phenyl rings increases the conjugation between the ring and the sulfur atom in a similar manner as that observed in diphenyl ethers. The mesityl ring is nearly orthogonal to the C—S—C plane.

Conformations of Bridged Diphenyls. X. Crystal Structure of 2-(4′-Carbomethoxy-2′-nitrophenylsulfinyl)-1,3,5-trimethylbenzene

1975 ◽  
Vol 53 (14) ◽  
pp. 2108-2114 ◽  
Author(s):  
Simon P. N. van der Heijden ◽  
W. David Chandler ◽  
Beverly E. Robertson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
X Ray Diffraction ◽  
X Ray ◽  
R Factor ◽  
Oxygen Atoms

The crystal structure of 2′-(4′-carbomethoxy-2′-nitrophenylsulfinyl)-1,3,5-trimethylbenzene, C17H17NO5S, has been determined by X-ray diffraction. The crystals are triclinic, a = 9.848(11), b = 7.654(10), c = 12.513(15) Å, α = 107.33(8), β = 100.73(8), γ = 106.53(8)°, [Formula: see text] with Z = 2. The intensities of 3850 independent reflections were measured on a four circle diffractometer; 2985 reflections were used in the refinement to give a final least-squares residual of 0.053 and a traditional R factor of 0.052.Repulsion between the sulfoxide oxygen atom and the nitro oxygen atoms forces the molecule into the twist-nitro-proximal conformation as opposed to the nitro-distal conformation which has been observed for other bridged diphenyls in this series.

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