# Entropy comparison of benzothiadiazole-based covalent-organic frameworks

**Authors:** Soniya Kurian, S. Roy, K. B. Gayathri, K. Jyothish

PMC · DOI: 10.3389/fchem.2025.1704165 · Frontiers in Chemistry · 2026-01-02

## TL;DR

This paper compares the structural properties of two benzothiadiazole-based COFs using topological indices and entropy analysis to determine their stability and connectivity.

## Contribution

The study introduces a theoretical framework using topological indices and entropy to evaluate COF structures for photocatalytic applications.

## Key findings

- PC-NPB shows higher connectivity through degree-based topological indices.
- PC-NB has lower entropy, indicating higher symmetry and structural regularity.
- Entropy analysis helps assess COF stability and crystallinity.

## Abstract

Covalent Organic Frameworks (COFs) are popular photocatalysts that utilize solar energy to generate hydrogen peroxide and evolve hydrogen because of their intrinsic porosity, robust framework, and excellent structural regularity. Benzothiadiazole-based donor-acceptor type COFs, PC-NB and PC-NPB, having distinct 
π
-bridges, influence electron transport and photocatalytic efficiency. Using degree-based topological indices and their entropy analysis, this study attempts to theoretically investigate the covalent organic frameworks PC-NB and PC-NPB to evaluate the structural complexity and stability. By offering an organized method for analyzing molecular graph features, edge partition facilitates the computation of topological indices. The calculated topological indices of the COFs are compared in detail and presented graphically. PC-NPB consistently shows higher values across nearly all degree-based topological indices, suggesting that it has a more connected structure. Additionally, lower entropy values in PC-NB indicate a higher degree of topological regularity and symmetry, which are traits frequently associated with enhanced rigidity, crystallinity, and thermodynamic stability.

## Linked entities

- **Chemicals:** benzothiadiazole (PubChem CID 67505), hydrogen peroxide (PubChem CID 784), hydrogen (PubChem CID 783)

## Full-text entities

- **Chemicals:** PC-NPB (-), hydrogen peroxide (MESH:D006861), hydrogen (MESH:D006859), Benzothiadiazole (MESH:C015700), PC-NB (MESH:C005805), COFs (MESH:D000073396)

## Full text

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## Figures

6 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12808347/full.md

## References

23 references — full list in the complete paper: https://tomesphere.com/paper/PMC12808347/full.md

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Source: https://tomesphere.com/paper/PMC12808347