Entropy changes and electron affinities from gas-phase electron-transfer equilibria: A- + B = A + B-

Chowdhury, Swapan K.; Heinis, Thomas; Grimsrud, E. P.; Kebarle, P.

doi:10.1021/j100403a037

Cited by 86 publications

(58 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A general increase of rigidity of the NO, group upon electron attachment is suggested by the values of the NO, wagging and rocking modes, which increase for the boron-containing species. This is consistent with the results obtained from measurements of electron-attachment equilibria for the nitrobenzene radical anion and substituted derivatives (7,8), which predict a stiffening of the NO, internal rotation on moving from neutral molecules to radical anions.…”

Section: Vibrational Frequenciessupporting

confidence: 91%

“…Likewise, structural changes due to the negative charge are suggested by entropy variations derived from electron attachment measurements in the gas phase (1,2). Negative entropy changes were determined for the nitrobenzene radical anion and substituted derivatives and this indicates a stiffening of the internal rotation of the NO, group moving from neutral to charged species (7,8).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Abinitio study on radical anions of nitro compounds

Ramondo¹

1992

Can. J. Chem.

View full text Add to dashboard Cite

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.

show abstract

Section: Vibrational Frequenciessupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Abinitio study on radical anions of nitro compounds

Ramondo¹

1992

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…236 Among various methods used the B3LYP/6-311G(3d,p) method yielding electron affinities within experimental error and within an average absolute magnitude of 0.05 eV of experimentally measured electron affinities. [237][238][239][240] Very recently the characterization of semiquinones and quinones formed as intermediates in the oxidation of flavonoid epicatechin has been studied by means of computational chemistry. 241 The antifungal and antioxidant activities of flavonoids depend on the stability of these semiquinones and quinones.…”

Section: Computational Investigations On 14-benzoquinonesmentioning

confidence: 99%

Recent advances in 1,4-benzoquinone chemistry

Abraham¹,

Joshi²,

Pardasani³

et al. 2011

J. Braz. Chem. Soc.

165

View full text Add to dashboard Cite

As 1,4-benzoquinonas são encontradas em toda a natureza, podendo ser sintetizadas por diversas estratégias. Esta revisão apresenta os desenvolvimentos recentes das metodologias de síntese, das reações de ciclo adição, da química computacional e dos estudos de pulso radiolítico. Destaca ainda a sua significância química e biológica e de seus compostos derivados.1,4-Benzoquinones are ubiquitous in nature and can be synthesized by diverse strategies. Recent developments on their synthetic methodologies, cycloaddition reactions, computational chemistry and pulse radiolytic studies are reported in this review. Their chemical and biological significance as well as their derivates' are also covered.

show abstract

“…The largest electron affinities are about 3 eV and nitrobenzene itself has a value of 1.01 eV. 35 It might therefore be expected that protonated nitrobenzene should have an electron affinity in the range 1.01 < EA < 3.0 eV. It has been pointed out that reduction potentials (E 1/2 ) should correlate with the orbital energy of the first unoccupied molecular orbital in a molecule.…”

mentioning

confidence: 99%

“…By using values for electron affinities for a series of compounds 35 and known E 1/2 reduction potentials for the same compounds, 37 a graph can be plotted, which gives a good linear correlation with, EA = 1.49(E 1/2 ) ϩ 2.79 eV (correlation coefficient = 0.9847). At the acidities used in the experiments described here, the E 1/2 value for nitrobenzene is Ϫ0.14 V.…”

mentioning

confidence: 99%

Investigations into the mechanism of action of nitrobenzene as a mild dehydrogenating agent under acid-catalysed conditions

et al. 2003

View full text Add to dashboard Cite

Protonated nitrobenzene can be used to dehydrogenate a range of hydrocarbons, which already possess at least one double bond. Kinetic and spectroscopic results, together with known electrode potentials, yield approximate limits within which protonated nitrobenzenes can be expected to effect dehydrogenation of hydroaromatic compounds. A high yielding synthesis of benzo[ j ]fluoranthene is described.

show abstract

Entropy changes and electron affinities from gas-phase electron-transfer equilibria: A- + B = A + B-

Cited by 86 publications

References 0 publications

Abinitio study on radical anions of nitro compounds

Abinitio study on radical anions of nitro compounds

Recent advances in 1,4-benzoquinone chemistry

Investigations into the mechanism of action of nitrobenzene as a mild dehydrogenating agent under acid-catalysed conditions

Contact Info

Product

Resources

About