Hybridization as a metric for the reaction coordinate of the chemical reaction. Concert in chemical reactions

Haddon, Robert C.; Chow, S.-Y.

doi:10.1351/pac199971020289

Cited by 16 publications

(10 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…But the chemistry of curved carbon materials reveals that local configurations play an important role in the bonding state of a carbon atom. 30 While a three-coordinated carbon atom sitting in an ideal trigonal geometry (the atom with its three nearest neighbors sitting in the same plane, all three bond angles equal to 120°, and all three bond lengths equal ϳ1.4 Å) is known to be in an sp 2 bonding state, the deviation from this configuration (for example, by curving the plane of the four atoms as in fullerenes and nanotubes) can lead to a substantial three-dimensional (sp 3 character) bonding structure of the three-coordinated atom, making the atom to acquire an intermediate bonding state which can be denoted as sp 2+␦ . This local distortion can lead to enhanced chemical reactivity of the carbon atoms that participate in the distortion.…”

Section: A the -Orbital Axis Vector Analysismentioning

confidence: 99%

Technique for the sp2∕sp3 characterization of carbon materials: Ab initio calculation of near-edge structure in electron-energy-loss spectra

Titantah

Lamoen

2004

Phys. Rev. B

View full text Add to dashboard Cite

We describe a technique to determine the sp 3 / sp 2 ratio of carbon materials which is based on the electronenergy-loss spectroscopy and which uses the theoretical spectrum of graphite obtained from ab initio electronic structure calculations. The method relies on the separation of the * and * components of the carbon K edge of graphite. The resulting * spectrum is adopted and assumed to be transferable to other carbon systems given an appropriate parametrization of the broadening. The method is applied on a series of Monte Carlo generated amorphous carbon structures and is shown to be stable over a wide range of the energy windows for which spectral integration is performed. The sp 3 fractions obtained using this method are found to be in good agreement with those obtained from a microscopic scheme which uses the -orbital axis vector analysis (POAV1). From the electron energy loss calculations on the generated amorphous carbon structures, we conclude that the interchangeable use of coordination number and hybridization state can lead to an underestimation of the sp 3 fraction of generated amorphous carbon structures for low and moderate densities. For high densities the coordination method and the POAV1 approach gave the same results. The technique was also applied on a series of spectra of plasma deposited amorphous carbon and was found to be in good agreement with the results obtained from a functional fitting approach.

show abstract

Section: A the -Orbital Axis Vector Analysismentioning

confidence: 99%

Technique for the sp2∕sp3 characterization of carbon materials: Ab initio calculation of near-edge structure in electron-energy-loss spectra

Titantah

Lamoen

2004

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…The curvature-induced re-hybridization effect has been included in the above structural analysis using the -orbital axis vector analysis (POAV) [45,46]. Table 2 shows the estimates of the sp 3 site fraction in simulated ta-C:H structures using coordination number (method 1), and -orbital axis vector analysis (method 2) calculations.…”

Section: Molecular Physics 1613mentioning

confidence: 99%

Tight-binding molecular dynamics study of the hydrogen-induced structural modifications in tetrahedral amorphous carbon

Ukpong¹

2010

Molecular Physics

View full text Add to dashboard Cite

A tight-binding molecular dynamics study of the structural evolution in tetrahedral amorphous carbon networks under dynamic hydrogen saturation is presented. The incorporation of hydrogen results in higher degrees of network disorder in second-neighbour distances, and initiates orbital re-hybridization that relaxes network stress. Using the simulated structures, numerical tests are performed to verify the effectiveness of a new structural order parameter for tetrahedrally-bonded solids. It is found that the island of accessible information, within the order parameter field shows a linear dependence between the fluctuations in first-and second-nearest-neighbour distances at a preferred orientation of 36 . A comparison with similar studies on hydrogenated amorphous silicon suggests that the local network structure of tetrahedrally-bonded amorphous solids obey the same ordering rule irrespective of differences in chemical species.

show abstract

“…In fact, an examination of the degree of pyramidalization of both the N and B atoms in this study shows that they are¯attened relative to the other eight similar molecules. Using the program POAV1 (Haddon, 1999), the pyramidalization angles at the N and B atoms in this study have averages of 16.4 and 13.6 , respectively (the angle for sp 2 is 0 and for sp 3 is 19.5 ). Average values for the other eight structures are 17.4 and 15.6 for N and B, respectively.…”

Section: Commentmentioning

confidence: 99%

Three chiral vinyldioxazaborocanes

et al. 2006

View full text Add to dashboard Cite

The structures of three chiral vinyldioxazaborocanes are reported, namely (2E)- and (2Z)-6-benzyl-2-buten-2-yl-1,3,6,2-dioxazaborocane, C27H30BNO2, (II) and (III), respectively, and (2Z)-2-buten-2-yl-6-isobutyl-1,3,6,2-dioxazaborocane, C24H32BNO2, (IV). These compounds may be useful in asymmetric reactions. In the structures reported here, the N-B donor-acceptor bond is longer than in any previously reported analogous compounds.

show abstract

Hybridization as a metric for the reaction coordinate of the chemical reaction. Concert in chemical reactions

Abstract: Abstract

Cited by 16 publications

References 0 publications

Technique for the sp2∕sp3 characterization of carbon materials: Ab initio calculation of near-edge structure in electron-energy-loss spectra

Technique for the sp2∕sp3 characterization of carbon materials: Ab initio calculation of near-edge structure in electron-energy-loss spectra

Tight-binding molecular dynamics study of the hydrogen-induced structural modifications in tetrahedral amorphous carbon

Three chiral vinyldioxazaborocanes

Contact Info

Product

Resources

About