  N-Carbophene (carbophene) is a novel class of two-dimensional covalent
organic frameworks (2DCOF), based on linear N-phenylenes, that have moderate
band gaps and low-mobility bands surrounding the Fermi energy; the simplest of
which may have been recently synthesized. Using tight-binding density
functional theory, the ground state configurations single layers, bilayers, and
bulk systems was determined. This work finds that carbophenes have formation
energies per carbon atom similar to that of graphenylene. The similarity of
formation energies between graphenylene and carbophene suggests that when
trying to synthesize one, the other may also be synthesized. The formation
energies could explain why the first reported synthesis of graphenylene also
indicated that they may have synthesized 3-carbophene. Results contained in
this work suggests that a carbophene was synthesized instead of graphenylene.
The projected density of states (PDOS) demonstrates that the anti-aromatic
nature of the cyclobutene units plays a direct role in the creation of bands
around the Fermi level, making this an exciting material in the theoretical
understanding of the nature of aromatic bonds.
