STERIC INHIBITION OF RESONANCE: V. NITROMESITYLENE

1959 ◽  
Vol 37 (9) ◽  
pp. 1487-1490 ◽  
Author(s):  
James Trotter
Keyword(s):  
Crystal Structure ◽  
Nitro Group ◽  
Aromatic Ring ◽  
Resonance Interaction ◽  
Vibration Frequencies ◽  
X Ray ◽  
Planar Model ◽  
Steric Inhibition Of Resonance

A detailed X-ray investigation of the crystal structure of nitromesitylene has shown that the nitro group is twisted 66° out of the plane of the aromatic ring about the C—N bond. The resulting decrease in resonance interaction compared with a completely planar model has been correlated with the characteristic NO2 vibration frequencies.

STERIC INHIBITION OF RESONANCE: I. 9-NITROANTHRACENE AND 9,10-DINITROANTHRACENE

1959 ◽  
Vol 37 (2) ◽  
pp. 351-357 ◽  
Author(s):  
James Trotter
Keyword(s):  
Crystal Structures ◽  
Nitro Derivative ◽  
Resonance Interaction ◽  
Vibration Frequencies ◽  
Characteristic Vibration ◽  
Aromatic Rings ◽  
X Ray ◽  
Steric Inhibition Of Resonance

Detailed X-ray analyses of the crystal structures of 9-nitroanthracene and 9,10-dinitro-anthracene have shown that the nitro groups are tilted out of the planes of the aromatic rings by 84.7° in the nitro derivative and 63.7° in the dinitro. The decreases in resonance interaction resulting from these deviations from coplanarity have been correlated with the characteristic vibration frequencies of the nitro groups.

scholarly journals Synthesis, crystal structure and antifungal activity of dihydroisoquinoline Oxaziridines Substitued in Position 1

2014 ◽  
Vol 10 (4) ◽  
pp. 2551-2557 ◽  
Author(s):  
Mouna Bouzid ◽  
Raed Abdennabi ◽  
Chakib Hrizi ◽  
Neji Gharsallah ◽  
Majed Kammoun
Keyword(s):  
Crystal Structure ◽  
Antifungal Activity ◽  
Nitro Group ◽  
Oxidizing Agent ◽  
X Ray ◽  
X Ray Crystallography

We report here the synthesis and the X-ray crystallography of dihydroisoquinoline oxaziridines with methyl substitute in position 1 and with nitro group in position 7 (compound 3b). We also synthesized the compound 3a without nitro. These compounds have been prepared by the peracidic oxidation of imines with m-chloroperbenzoic (m-CPBA) like oxidizing agent. This two compounds exhibit higher antifungal activity.

scholarly journals Crystal structure of 2-phenylethylaminium 4-nitrophenolate monohydrate

2014 ◽  
Vol 70 (12) ◽  
pp. o1280-o1280
Author(s):  
N. Swarna Sowmya ◽  
S. Sampathkrishnan ◽  
S. Sudhahar ◽  
R. Mohan Kumar ◽  
G. Chakkaravarthi
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Nitro Group ◽  
Aromatic Ring ◽  
Three Dimensional ◽  
Side Chain ◽  
Stacking Interactions ◽  
Dimensional Network ◽  
Centroid Distance ◽  
Molecular Salt

In the title hydrated molecular salt, C8H12N+·C6H4NO3−·H2O, the conformation of the side chain in the cation isanti[C—C—C—N = 179.62 (12)°] and the dihedral angle between the aromatic ring and the nitro group in the anion is 3.34 (11)°. In the crystal, the components are linked by O—H...O and N—H...O hydrogen bonds, generating (10-1) sheets, which featureR44(21) loops. The sheets interact by weak aromatic π–π stacking interactions [centroid–centroid distance = 3.896 (3) Å], forming a three-dimensional network.

scholarly journals The crystal structure of para-dinitrobenzene

1935 ◽  
Vol 153 (878) ◽  
pp. 225-246 ◽  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Nitro Group ◽  
Aromatic Compounds ◽  
X Rays ◽  
Slow Evaporation ◽  
Fourier Synthesis ◽  
X Ray ◽  
Full Analysis ◽  
Atomic Parameters

The crystallography and optical properties of para-dinitrobenzene were first studied by Bodewig in 1876. Investigations bf means of X-rays have recently been made by Hertel, who determined the unit cell and the space group and tentatively proposed a structure, and by Banerjee, who applied the method of Courier Fourier synthesis and gave a set of atomic parameters. A brief examination of the intensities of a few X-ray spectra shown that the structure proposed by Hertel cannot be correct, and it was therefore decided to attempt a full analysis, with a view to determining the size and shape of the nitro group in aromatic compounds. During the course of the work Banerjee's paper was published. We are, however, unable to agree with his conclusions, and the structure proposed as a result of the work to be described here differs radically from his. Crystallography and Optical Properties Very beautiful crystals of para-dinitrobenzene may be obtained by the slow evaporation of a solution in acetone. They are pale lemon-fellow in colour, and the smaller ones are very clear and free from flaws, and have brilliantly rejecting faces. Crystals several millimetres across may easily be grown, but these are usually 1ess perfect than the smaller ones. The crystals belong to the monoclinic holohedral class, and Bodewig gives for the monoclinic angle and the axial ratios β = 90° 18', a : b: c = 2·038 : 1 : 1·043, values which are closed confirmed by goniometer measurements made during the course of this work.

Molecular and Crystal Structure of Two Anthracene Derivatives and their 1,4-Endoperoxides. Influence of the Aromatic Ring Distortion upon the Steric Acceleration of the 1,4-Addition of Singlet Oxygen

1999 ◽  
Vol 52 (3) ◽  
pp. 213
Author(s):  
Nacer Lahrahar ◽  
Henri Bouas-Laurent ◽  
Jean-Pierre Desvergne ◽  
Pierre Marsau ◽  
Jean Rigaudy
Keyword(s):  
Crystal Structure ◽  
Singlet Oxygen ◽  
Aromatic Ring ◽  
Structure Determination ◽  
Molecular Structures ◽  
X Ray ◽  
Anthracene Derivatives ◽  
Oxygen Addition ◽  
Ring Distortion

The X-ray structure determination of two anthracene derivatives, namely 1,2,3,4-tetramethylanthracene (TMA) and 1,2,3,4-tetramethyl-9,10-diphenylanthracene (TMDPA), and of their endoperoxides, 1,2,3,4- tetramethyl-1,4-dihydro-1,4-epidioxyanthracene (TMAPO) and 1,2,3,4-tetramethyl-9,10-diphenyl-1,4-dihy- dro-1,4-epidioxyanthracene (TMDPAPO), has been performed. The compared analysis of the conformations of the four molecular structures strongly suggests that the steric acceleration observed for singlet oxygen addition to TMDPA should be attributed to the important distortion of the anthracene nucleus.

STERIC INHIBITION OF RESONANCE: III. CALCULATION OF RESONANCE ENERGIES AND BOND LENGTHS

1959 ◽  
Vol 37 (5) ◽  
pp. 905-914 ◽  
Author(s):  
James Trotter
Keyword(s):  
Nitro Group ◽  
Bond Order ◽  
Electron Distribution ◽  
Resonance Energy ◽  
Nitro Compounds ◽  
X Ray ◽  
Bond Lengths ◽  
Resonance Energies ◽  
Aromatic Nitro ◽  
Steric Inhibition Of Resonance

In many aromatic nitro compounds steric effects prevent the attainment of complete coplanarity and inhibit resonance interaction between the nitro group and the aromatic π-electrons. The variations with nitro group tilt of resonance energy, electron distribution, and π-bond order in this type of molecule have been calculated by molecular orbital methods, and the corresponding bond length variations have been deduced. The calculated bond lengths for 9,10-dinitroanthracene and 9-nitroanthracene are compared with those measured by X-ray analyses.

scholarly journals Crystal structure of 2,6-dichloro-4-nitropyridineN-oxide

2015 ◽  
Vol 71 (10) ◽  
pp. o775-o775 ◽  
Author(s):  
Andrew M. Prichard ◽  
Will E. Lynch ◽  
Clifford W. Padgett
Keyword(s):  
Crystal Structure ◽  
Nitro Group ◽  
Aromatic Ring ◽  
Title Compound ◽  
Twist Angle ◽  
Compound C ◽  
Oxide Group

In the title compound, C5H2Cl2N2O3, the nitro group is essentially coplanar with the aromatic ring, with a twist angle of 4.00 (6)° and a fold angle of 2.28 (17)°. The crystal structure exhibits a herringbone pattern with the zigzag running along thebaxis. The herringbone layer-to-layer distance is 3.0075 (15) Å, with a shift of 5.150 (4) Å. Neighboring molecules are tilted at a 57.83 (4)° (ring-to-ring) angle with each other. The nitro group on one molecule points to theN-oxide group on the neighboring one, with an intermolecular O...N(nitro) distance of 3.1725 (13) Å.

Crystal Structure of Sodium O,O'-Nitritonitroargentate(I)

1979 ◽  
Vol 32 (2) ◽  
pp. 297
Author(s):  
BW Skelton ◽  
AH White
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Least Squares ◽  
Nitro Group ◽  
Title Compound ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Full Matrix ◽  
X Ray ◽  
Linear Coordination

The crystal structure of the title compound, NaAg(NO2)2, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by full-matrix least squares to a residual of 0.043 for 449 'observed' reflections. Crystals are orthorhombic, space group Fd2d, a 7.913(2), b 10.721(2), c 10.857(3) �, Z 8. The structure is closely related to that of sodium and silver nitrites; the silver environment is dominated by the 'linear' coordination of a nitro group (Ag-N 2.25(2) �) and a 'chelating' pair of oxygen atoms from another NO2- species (Ag-O 2.422(8)�), the O2N-Ag-O2N group containing a crystallographic 2 axis.

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