A robust spin-coupled tetraradical via nonalternant design
Year: 2026
Type: article
Abstract: Polyradicals in open-shell polycyclic hydrocarbons (PHs) offer access to multiple spin states and hold great promise for spintronics and quantum technologies. Here we report a nonalternant, air-stable tetraradical featuring two fused 7-5-7 rings and a strongly correlated singlet ground state. This molecule displays an exceptional tetraradical character ( y 0 = 1.00, y 1 = 0.89) and exhibits long ambient stability ( t 1/2 = 33 days). Comprehensive electronic structure and magnetic response analyses reveal that the spin topology is governed by both ferromagnetic and antiferromagnetic interactions, with robust electron correlation ( J 1 = +321 K, J 2 = −44 K, and J 3 = −29 K). The unique nonalternant design suppresses hyperfine and vibrational decoherence, giving rise to long spin relaxation and coherence time. These findings demonstrate that embedding nonalternant motifs into PH polyradicals provides a powerful strategy to simultaneously promote molecular stability, spin-exchange coupling, and spin robustness—key features for materials in the rising field of quantum information science.
Source: Science Advances
Institutions: University of Hong Kong, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Donostia International Physics Center, Southeast University, Ikerbasque, Universidad de Málaga, Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area, State Key Laboratory of Synthetic Chemistry
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,500
OpenAlex ID: W7225421899