# Chemists synthesize an air-stable organic tetraradical with fused 7-5-7 rings

- Published: 2026-11-07 21:53 UTC
- Section: Science › Chemistry
- Tags: Science Advances, organic tetraradical, nonalternant hydrocarbon, spin coherence, open shell polycyclic hydrocarbon, molecular spintronics
- URL: https://realtech.media/news/rt-be09e916222ed1c38f856571_chemists_synthesize_an/

**Researchers synthesized a nonalternant hydrocarbon tetraradical in the lab, achieving a 33-day ambient half-life alongside strong spin coupling.**

![Chemists synthesize an air-stable organic tetraradical with fused 7-5-7 rings](https://realtech.media/media/2026/11/ff372d1f4ad49412.jpg)
*Stephanie Sizemore and Ian Coddington/NIST, Wikimedia Commons, Public domain*

Chemists reported the synthesis and characterization of an air-stable polycyclic hydrocarbon tetraradical in the journal Science Advances [1]. The open-shell molecule incorporates a nonalternant framework of two fused 7-5-7 ring motifs and exhibits a strongly correlated singlet ground state [1]. Under ambient conditions, the synthesized compound demonstrated a half-life of 33 days [1].

Measurements confirmed high radical character, with indices calculated at y0 = 1.00 and y1 = 0.89 [1]. Magnetic response analyses revealed competing exchange interactions with coupling constants of J1 = +321 K, J2 = −44 K, and J3 = −29 K, indicating coexistence of ferromagnetic and antiferromagnetic pathways [1].

According to the authors, the nonalternant architecture effectively suppresses hyperfine and vibrational decoherence [1]. This design achieved long spin relaxation and coherence times, providing a strategy to balance chemical stability and spin interactions in open-shell organic frameworks for quantum information science [1].

## Sources

1. [Science Advances](https://doi.org/10.1126/sciadv.aef6604)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-be09e916222ed1c38f856571_chemists_synthesize_an/