Exploring the similarity of single-layer covalent organic frameworks using electronic structure calculations

Area of Science:

• Materials Science
• Condensed Matter Physics
• Computational Chemistry

Background:

• Two-dimensional covalent organic frameworks (2D COFs) are emerging materials with tunable properties.
• Exploring their electronic characteristics is crucial for diverse applications.
• Monomer combinations offer pathways to novel materials with tailored physico-chemical properties.

Purpose of the Study:

• Investigate the electronic properties of 2D COFs with square lattice topology.
• Classify 2D COFs based on π-conjugation degree.
• Understand the impact of aromaticity on electronic structure.

Main Methods:

• Tight-binding density functional theory approach.
• Analysis of electronic band structures.
• Development of a similarity measure for COF classification.

Main Results:

• A classification of 2D COFs based on π-conjugation was established.
• This classification was successfully reproduced using electronic band-structure similarity.
• Aromaticity was identified as a key factor governing the electronic band-structure of fully-conjugated COFs.

Conclusions:

• Electronic properties of 2D COFs are strongly dictated by π-conjugation and aromaticity.
• Band-structure features can effectively classify these materials.
• This research provides fundamental insights into designing 2D COFs with desired electronic functionalities.