Molecular structure of nitrobenzene in the planar and orthogonal conformations

Domenicano, Aldo; Schultz, György; Hargittai, István; Colapietro, Marcello; Portalone, Gustavo; George, Philip; Bock, Charles W.

doi:10.1007/bf00675790

Cited by 135 publications

(115 citation statements)

References 49 publications

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“…Thus, it can be concluded that the H5 … methyl repulsive interaction is important either from a structural or from an energetic point of view. Indeed, it is also noteworthy that, while the predicted ring angles, calculated using the geometrical substituent parameters taken from the literature [35,36] reproduce quite well the observed ring angles of anisic acid (Fig. 8), the agreement is much better for the angles corresponding to the less strained side of the aromatic ring.…”

Section: The O-ch 3 Internal Rotationsupporting

confidence: 62%

Molecular structure and charge density analysis of p-methoxybenzoic acid (anisic acid)

Fausto

Beja

Paixão

1997

Journal of Molecular Structure

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A concerted X-ray and ab initio SCF-MO study of the structure and charge density of p-methoxybenzoic acid (anisic acid) is reported. An extensive X-ray data set (7401 reflections) was measured on a single crystal using Mo Ka radiation and the structure refined with 2121 unique reflections, leading to a final R(F)-factor of 0.047 calculated for reflections with I Ͼ 2j. The molecular geometry of crystalline anisic acid, where the molecules dimerize via a moderately strong CyO-H … O hydrogen bond, is compared with that of the isolated molecule, resulting from SCF-MO ab initio calculations. A topological analysis of the molecular charge density was performed using Bader's method to gain insight into the dominant intra-and intermolecular interactions in this compound. In particular, the effects of the substituents on the observed distortions of the benzene ring were investigated as well as the internal rotation of the methyl group. ᭧ 1997 Elsevier Science B.V.

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Section: The O-ch 3 Internal Rotationsupporting

confidence: 62%

Molecular structure and charge density analysis of p-methoxybenzoic acid (anisic acid)

Fausto

Beja

Paixão

1997

Journal of Molecular Structure

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“…The geometry of the NO, group of C,H,NO,-reveals a remarkaFle increase in the value of the NO bond length (0.080 A) and decrease in the O N 0 bond angle (2.5") with respect to the calculated values for the neutral precursor (29). A more marked change is calculated for the CN bond length, which is 0.091 A shorter in the molecular anion.…”

Section: Molecular Structuresmentioning

confidence: 67%

Abinitio study on radical anions of nitro compounds

Ramondo¹

1992

Can. J. Chem.

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This paper is dedirnted to Professor Sigeru Huzinaga on the occasion of his 65th birthdayFABIO RAMONDO. Can. J. Chem. 70, 3 14 (1992).The results of ab itritio molecular orbital calculations on some nitro compounds, RN02 (R = CH,, CF,, CH,F, BH,, BF,, BHF, C6H5) and on the corresponding radical anions are reported. The geometries of the neutral and charged species were optimized at the SCF and MP2 levels of theory employing the 6-31G* and the 6-3 1 +G* basis sets. The rotation about the CN and BN bonds reveals distinct conformations for each molecule and vibrational frequencies were determined for such structures. All the employed levels of theory predict structural differences between neutral and charged molecules. The major geometrical changes occurring by electron adding to R N 0 2 consist in the lengthening of the NO bonds and in the shortening of the CN and BN bonds. The radical anions are calculated to be pyramidal at nitrogen in the stable conformers of CH,NO,-, CF3N02-, CH,FNO,-, while, for the T-electron-accepting substituents (BH,, BHF, BF,, C6H5), the anion is planar. Electron correlation energy corrections in the framework of Moiler-Plesset perturbation theory were included to determine relative stabilities between different conformations. At the MP4/6-3 1G*//MP2/ 6-31G* level, an easy rotation of the NO, group is predicted for all the radical anions and neutral molecules with the exception of BH?NO,-, BF2N02-, and BHFN0,-, which show high torsional barriers about the BN bond.

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“…The nitrobenzene ring of indazole derivative 18 reveals considerable deviations concerning some bonds in comparison with nitrobenzene. The C4-C5 bond is particularly short (1.35 Å vs. 1.3989 Å in nitrobenzene 15 ). As a similar value for the C4-C5 bond length can be predicted for nitroindazole 3, this bond shortening may be crucial for the orientation in the nucleophilic substitution.…”

Section: Methodsmentioning

confidence: 96%

On the reactions of tertiary carbanions with some nitroindazoles and nitrobenzotriazoles

Bernard¹,

Kujawski²,

Skierska³

et al. 2012

Arkivoc

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The vicarious nucleophilic substitution in some nitroindazole and nitrobenzotriazole derivatives with tertiary carbanions leads almost exclusively to products substituted para to the nitro group. As results from the theoretical calculations and structural evidences, such reaction outcome is due mainly to the stereoelectronic reasons in combination with the considerable shortening of the Cortho-CNO2 bond. The presence of the chiral and prochiral centres (the methine and Nmethylene groups, respectively) often gives rise to additional splitting of the methylene protons signal that is transmitted on a long distance provided there is no pyridinic nitrogen in the pathway of coupling.

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Molecular structure of nitrobenzene in the planar and orthogonal conformations

Cited by 135 publications

References 49 publications

Molecular structure and charge density analysis of p-methoxybenzoic acid (anisic acid)

Molecular structure and charge density analysis of p-methoxybenzoic acid (anisic acid)

Abinitio study on radical anions of nitro compounds

On the reactions of tertiary carbanions with some nitroindazoles and nitrobenzotriazoles

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