ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

DFT study of benzo[a,c]phenazine-oligothiophene monomers: tuning electronic structure and n-type character

Hugo Torres-Jiménez, Samuel Soto-Acosta, Tomás Delgado-Montiel, Manuel Luque-Román, Carlos A. Peñuelas, Daniel Glossman-Mitnik, Jesús Baldenebro-López, and Rody Soto-Rojo

Facultad de Ingeniería Mochis, Universidad Autónoma de Sinaloa, Los Mochis, Mexico

E-mail: 16085671.torres@ms.uas.edu.mx

Received: 6 November 2025  Accepted: 19 March 2026

Abstract:

This study systematically evaluates ten π-conjugated monomers featuring a benzo[a,c]phenazine core and oligothiophene chains. Extension of the thiophene chains enhances molecular planarity and stabilizes conformational symmetry, reducing the energy gap from 3.53 eV (M1) to 2.68 eV (M10). Multiple lines of evidence, including conceptual DFT descriptors and electron reorganization energies, indicate that these are lower than hole reorganization energies, establishing robust n-type character. Electron density difference maps and transition density matrix plots further confirm efficient intramolecular charge transfer and exciton delocalization. M10 emerges as the most promising precursor for high-performance n-type conducting polymers, attributed to its low chemical hardness (3.54 eV) and high electron affinity (1.86 eV).

Keywords: Conducting polymers; Benzo[a,c]phenazine; Oligothiophene; Donor–acceptor

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-04827-0

Chemical Papers 80 (7) 7425–7439 (2026)