Solution-synthesized stable triaza[4]triangulene triradical with a quartet ground state
As a renowned class of open-shell molecules characterized by triangular nanographenic structures and novel magnetic properties with high-spin ground states, triangulenes are attractive targets to both synthetic chemists and molecular magnet researchers. Here, a highly stable aza-derivative of [4]triangulene triradical (1) is achieved, with a quartet ground state (S = 3/2). By virtue of the stability under ambient conditions (τ<sub>1/2</sub> ~ 9 days in the solid state and 28 h in an air-saturated solution), thorough structural and magnetic characterizations are performed. Crystallographic analysis confirms that 1 has a planar triangular polycyclic aromatic skeleton embedded with delocalized spins. Concurrently, continuous-wave and pulsed EPR spectroscopies provide unambiguous evidence supporting its high-spin ground state. SQUID measurements reveal impressively large doublet-quartet energy gap (ΔE<sub>D-Q</sub> = 3.18 kcal/mol), indicating very strong intramolecular ferromagnetic spin-spin exchanges (J/k<sub>B</sub> = +534 K) rendered by the triangulene structure.
Authors
- Xudong Bai
- Yanning Cheng
- Yihan Wang (ORCID: https://orcid.org/0009-0005-5365-5988)
- Shang-Da Jiang
- Yi Xie
- Yushuang Zhang
- Dahui Zhao
- Di Zhang
- Ziqi Zhu
Institutions
- Hong Kong Science and Technology Parks Corporation (HK)
- Institute of Molecular Functional Materials (CN)
- Beijing National Laboratory for Molecular Sciences (CN)
- South China University of Technology (CN)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-02-03
- DOI
- https://doi.org/10.1038/s41467-026-69048-1
- Primary Topic
- Synthesis and Properties of Aromatic Compounds
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China
- Peking University
- Fundamental Research Funds for the Central Universities
- Beijing National Laboratory for Molecular Sciences