Oral Presentation Royal Australian Chemical Institute National Congress 2026

Theoretical studies of radical boron heterocycles (136928)

David Wilson 1
  1. La Trobe University, Bundoora, VIC, Australia

Boron-doped PAH systems that possess open- and closed-shell behavior attract significant attention due to their inherent redox and charge transport properties. In this presentation, I will outline computational efforts to predict and rationalise experimental observation of radical character of novel boron heterocycles. We have recently investigated open-shell radicals [JACS, 146, 6145, 2024], diradicals [JACS, 146, 6506, 2024], and even tetraradicals [JACS, 147, 33359, 2025]. The tetraradical complex is the first reported boron tetraradical, with a ground state singlet configuration. The electronic structure of these systems is challenging and requires extensive multireference CASSCF or broken-symmetry DFT (BS-DFT) to correctly model open-shell singlet (OSS) states. Analysis of spin density, natural orbitals, molecular orbitals, and biradical character will be presented. For several systems we were able to assess the effect of geometry on radical character. Aromaticity is explored with ACID and NICS analysis.

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  4. S. K. Sarkar, K. K. Hollister, A. Molino, A. D. Obi, C.-L. Deng, B. Y. E. Tra, B. M. Stewart, D. A. Dickie, D. J. D. Wilson, R. J. Gilliard, Jr, J. Am. Chem. Soc., 145, 21475–21482 (2023) https://doi.org/10.1021/jacs.3c07236