Journal article

Publication year: 2015

Pages: 1621-1630

Journal: Journal of Chemical Theory and Computation

Volume number: 11

Issue number: 4

ISSN: 1549-9618

DOI Link: https://doi.org/10.1021/acs.jctc.5b00075

Publisher: American Chemical Society

Abstract: 

We investigated the nature of the cohesive energy between graphane
sheets via multiple CH···HC interactions, using density functional
theory (DFT) including dispersion correction (Grimme’s D3 approach)
computations of [n]graphane σ dimers (n = 6–73). For
comparison, we also evaluated the binding between graphene sheets that
display prototypical π/π interactions. The results were analyzed using
the block-localized wave function (BLW) method, which is a variant of ab initio valence bond (VB) theory. BLW interprets the intermolecular interactions in terms of frozen interaction energy (ΔE_F) composed of electrostatic and Pauli repulsion interactions, polarization (ΔE_pol), charge-transfer interaction (ΔE_CT), and dispersion effects (ΔE_disp).
The BLW analysis reveals that the cohesive energy between graphane
sheets is dominated by two stabilizing effects, namely intermolecular
London dispersion and two-way charge transfer energy due to the σ_CH → σ*_HC
interactions. The shift of the electron density around the nonpolar
covalent C–H bonds involved in the intermolecular interaction decreases
the C–H bond lengths uniformly by 0.001 Å. The ΔE_CT
term, which accounts for ∼15% of the total binding energy, results in
the accumulation of electron density in the interface area between two
layers. This accumulated electron density thus acts as an electronic
“glue” for the graphane layers and constitutes an important driving
force in the self-association and stability of graphane under ambient
conditions. Similarly, the “double faced adhesive tape” style of charge
transfer interactions was also observed among graphene sheets in which
it accounts for ∼18% of the total binding energy. The binding energy
between graphane sheets is additive and can be expressed as a sum of CH···HC interactions, or as a function of the number of C–H bonds.

Harvard Citation style: Wang, C., Mo, Y., Wagner, J., Schreiner, P., Jemmis, E., Danovich, D., et al. (2015) The Self-Association of Graphane Is Driven by London Dispersion and Enhanced Orbital Interactions, Journal of Chemical Theory and Computation, 11(4), pp. 1621-1630. https://doi.org/10.1021/acs.jctc.5b00075

APA Citation style: Wang, C., Mo, Y., Wagner, J., Schreiner, P., Jemmis, E., Danovich, D., & Shaik, S. (2015). The Self-Association of Graphane Is Driven by London Dispersion and Enhanced Orbital Interactions. Journal of Chemical Theory and Computation. 11(4), 1621-1630. https://doi.org/10.1021/acs.jctc.5b00075