arXiv subjects

Elena Sheka

Publications and source records attributed to Elena Sheka.

4 recordsLinked to original sources

arXiv2014

Stretching and breaking of chemical bonds, correlation of electrons, and radical properties of covalent species

Chemical bonds are considered in light of correlation of valence electrons that is strengthened when the bond is dissociated. In the framework of the unrestricted Hartree-Fock single-reference version of the configuration interaction theory, effectively unpaired electrons lay the foundation of the electron correlation measure in terms of total number of the electrons (molecular chemical susceptibility). graphs and their singularities with respect to the interatomic distance allow presenting a quantitative description of stretching and breaking of chemical bonds. The approach validity is demonstrated on a large number of bonds of different order and chemical composition.

cond-mat.mtrl-sci↗

arXiv2013

Topological mechanochemistry of graphene

In view of a formal topology, two common terms, namely, connectivity and adjacency, determine the quality of C-C bonds of sp2 nanocarbons. The feature is the most sensitive point of the inherent topology of the species so that such external action as mechanical deformation should obviously change it and result in particular topological effects. The current paper describes the effects caused by uniaxial tension of a graphene molecule in due course of a mechanochemical reaction. Basing on the molecular theory of graphene, the effects are attributed to both mechanical loading and chemical modification of edge atoms of the molecule. The mechanical behavior is shown to be not only highly anisotropic with respect to the direction of the load application, but greatly dependent on the chemical modification of the molecule edge atoms thus revealing topological character of the graphene deformation.

cond-mat.mtrl-sci↗

arXiv2013

Effect of chemical modification of edge atoms of graphene sheets on their strength

Basing on the molecular theory of graphene, the influence of the chemical modification of edge atoms of a graphene sheet is studied in terms of mechanochemical reactions. The mechanical behavior of graphene is shown to be not only highly anisotropic with respect to the direction of the load application, but greatly dependent on the chemical modification of the edges as well. A topological character of the graphene deformation is discussed.

cond-mat.mtrl-sci↗

arXiv2011

When a covalent bond is broken?

The current contribution suggests the application of the effectively-unpaired-electron concept to describe stretching and breaking of chemical bonds quantitatively.

physics.chem-ph↗