N-Carbophenes: two-dimensional covalent organic frameworks derived from linear N-phenylenes

TL;DR

This paper introduces N-Carbophenes, a new class of 2D covalent organic frameworks derived from linear N-phenylenes, with potential for synthesis and unique electronic properties related to aromatic bonds.

Contribution

It provides theoretical insights into the stability and electronic structure of N-Carbophenes, suggesting their feasible synthesis and relation to graphenylene.

Findings

Carbophenes have formation energies similar to graphenylene.

Potential synthesis of carbophenes may have been achieved instead of graphenylene.

Anti-aromatic cyclobutene units influence electronic bands near the Fermi level.

Abstract

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.