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E.F. Sheka et al.
have become an inherent part of not only organic, but inorganic chemistry, as well.
The readers, who are interested in this topic, are referred to a set of comprehensive
reviews [3, 6–9], but a few. The current situation in this field can be seen by the
example of a direct structural understanding of the topochemical solid state photopolymerization reaction [10].
Nowadays, we are witnessing the next pulse, stimulating investigations in the
field, which should be attributed to the appearance of a new class of the spatially extended molecular materials, such as sp 2 nanocarbons. Obviously, the main members
of the class such as fullerenes, nanotubes, and numerous graphene-based species
are absolutely different from the formal topology viewpoint. Thus, fullerenes exist
in the form of a hollow sphere, ellipsoid, or tube consisting of differently packed
benzenoid units. Carbon nanotubes present predominantly cylindrical packing of
the units. In graphene, the benzenoid units form one-atom-thick planar honeycomb
structure. If we address the common terms of the formal topology, namely, connectivity and adjacency, we have to intuitively accept their different amount in the above
three species. In its turn, the connectivity and adjacency determine the ‘quality’ of
the C–C bond structure of the species, thus, differentiating them by this mark. Since
non-saturated C–C bonds are the main target for chemical reactions of any type, one
must assume that identical reactions, involving the bonds, will occur differently for
different members of the sp 2 nanocarbon family. Therefore, one may conclude that
the spatially extended sp 2 nanocarbons present not only peculiar structural chemicals, but the class of species for which the formal and empirical topology overlap.
At the first time, the results, presented in [11, 12] have revealed this tight interconnection in terms of the molecular quantum theory. Not only fullerenes, but carbon
nanotubes and graphene (their fragments) have been considered at the molecular
level. The obtained results are related to the computational study of the intermolecular interaction between one of the above sp 2 nanocarbon molecules and one of
the other addends, among which there are both sp 2 nanocarbons and monoatomic
species. The intermolecular interaction lays the foundation of any reaction so that
its topological peculiarities may evidence a topochemical character of the reaction
under study. However, since the ‘quality’ of the C–C bonds is the most sensitive
point of the inherent topology of the sp 2 nanocarbons, external actions, such as mechanical deformation, on the bonds should obviously result in particular topological
effects that accompany the relevant intramolecular reactions. The current chapter is
devoted to the discussion of such reactions that are presented by the mechanochemical one related to the uniaxial tension of a graphene molecule.
16.2 Uniaxial Tension of Graphene as a Mechanochemical
Reaction
Below we will consider a particular topological effect caused by the influence of
both the loading direction and the graphene molecule edge termination on the inherited topology of the molecule. As turned out, the graphene deformation under
E.F. Sheka et al.
have become an inherent part of not only organic, but inorganic chemistry, as well.
The readers, who are interested in this topic, are referred to a set of comprehensive
reviews [3, 6–9], but a few. The current situation in this field can be seen by the
example of a direct structural understanding of the topochemical solid state photopolymerization reaction [10].
Nowadays, we are witnessing the next pulse, stimulating investigations in the
field, which should be attributed to the appearance of a new class of the spatially extended molecular materials, such as sp 2 nanocarbons. Obviously, the main members
of the class such as fullerenes, nanotubes, and numerous graphene-based species
are absolutely different from the formal topology viewpoint. Thus, fullerenes exist
in the form of a hollow sphere, ellipsoid, or tube consisting of differently packed
benzenoid units. Carbon nanotubes present predominantly cylindrical packing of
the units. In graphene, the benzenoid units form one-atom-thick planar honeycomb
structure. If we address the common terms of the formal topology, namely, connectivity and adjacency, we have to intuitively accept their different amount in the above
three species. In its turn, the connectivity and adjacency determine the ‘quality’ of
the C–C bond structure of the species, thus, differentiating them by this mark. Since
non-saturated C–C bonds are the main target for chemical reactions of any type, one
must assume that identical reactions, involving the bonds, will occur differently for
different members of the sp 2 nanocarbon family. Therefore, one may conclude that
the spatially extended sp 2 nanocarbons present not only peculiar structural chemicals, but the class of species for which the formal and empirical topology overlap.
At the first time, the results, presented in [11, 12] have revealed this tight interconnection in terms of the molecular quantum theory. Not only fullerenes, but carbon
nanotubes and graphene (their fragments) have been considered at the molecular
level. The obtained results are related to the computational study of the intermolecular interaction between one of the above sp 2 nanocarbon molecules and one of
the other addends, among which there are both sp 2 nanocarbons and monoatomic
species. The intermolecular interaction lays the foundation of any reaction so that
its topological peculiarities may evidence a topochemical character of the reaction
under study. However, since the ‘quality’ of the C–C bonds is the most sensitive
point of the inherent topology of the sp 2 nanocarbons, external actions, such as mechanical deformation, on the bonds should obviously result in particular topological
effects that accompany the relevant intramolecular reactions. The current chapter is
devoted to the discussion of such reactions that are presented by the mechanochemical one related to the uniaxial tension of a graphene molecule.
16.2 Uniaxial Tension of Graphene as a Mechanochemical
Reaction
Below we will consider a particular topological effect caused by the influence of
both the loading direction and the graphene molecule edge termination on the inherited topology of the molecule. As turned out, the graphene deformation under