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. 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. 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. 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.

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. 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°.

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.

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.

scholarly journals Conformations of Bridged Diphenyls. II. Crystal Structure of 2-(2′,4′-Dinitrophenoxy)-1,3,5-tri-t-butylbenzene

1972 ◽  
Vol 50 (18) ◽  
pp. 2972-2978 ◽  
Author(s):  
E. A. H. Griffith ◽  
W. D. Chandler ◽  
B. E. Robertson
Keyword(s):  
Crystal Structure ◽  
Oxygen Atom ◽  
Least Squares ◽  
Bond Angle ◽  
The Other ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ether Oxygen Atom ◽  
Phenyl Rings ◽  
Ether Oxygen

The structure of 2-(2′,4′-dinitrophenoxy)-1,3,5-tri-t-butylbenzene, C24H32N2O5, has been determined by X-ray diffraction. The crystals are triclinic, a = 12.160(30), b = 10.564(17), c = 10.684(16) Å, α = 119.23(10), β = 96.06(15), γ = 96.55(15)°, [Formula: see text] with Z = 2. The intensities of 5359 independent reflections were measured on a four circle diffractometer of which 2471 were used in the refinement to give a final least-squares weighted residue of 0.063. The presence of two electron withdrawing groups on one of the phenyl rings increases the conjugation between the ring and the ether oxygen atom to a greater degree than was found in the previous work. The tri-t-butyl-substituted ring is nearly orthogonal to the other ring. The bond angle at the ether oxygen atom is less than the value found earlier but ring distortions are similar.

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