Chlorgraphynes: formation path, structure and electronic properties

The presence in graphyne sheets of a variable amount of $sp^2$ and $sp^1$ carbon atoms suggests a high ability of these nanostructures for saturation. E.g., covalent binding of chlorine atoms would lead to $sp^3$- and new $sp^2$ hybridized carbon atoms, and the emergence of chlorgraphynes (chlorinated graphynes) with variable Cl/C stoichiometry may be expected. Here, employing DFT band structure calculations, a series of new graphyne derivatives – layered chlorgraphynes – is examined on example of $\alpha$-graphyne. The possible formation path of chlorgraphynes as a set of consecutive free-radical additions of Cl atoms is established. From examples of a few representative compounds, the trends in the structural and electronic properties are discussed, depending on their stoichiometry.