3,3',3''-(Benzene-1,3,5-triyl)tris(1-phenyl-1H-benzo[e][1], [2], [4]triazin-4-yl) (1) is a C3-symmetrical triradical comprised of three Blatter radical units connected at the 1, 3, 5 positions of a central trimethylenebenzene core. This triradical has an excellent air, moisture, and thermal stability. Single-crystal XRD indicates that triradical 1 adopts a propeller-like geometry with the benzotriazinyl moieties twisted by 174.1(2)° and packs in 1D chains along the c axis to form an extensive network of weak intermolecular interactions. Frozen solution continuous wave (CW) EPR spectra and variable-temperature field-sweep echo-detected (FSED) spectra revealed an intramolecular ferromagnetic exchange within the spin system, supporting a quartet S = 3/2 ground state. DFT calculations further supported these experimental findings.
Deciphering the Ground State of a C3-Symmetrical Blatter-type Triradical by CW and pulse EPR Spectroscopy
Athanassios K. Boudalis, Christos P. Constantinides, Nicolas Chrysochos, Raanan Carmieli, Gregory Leitus, Andreas Kourtellaris, Daniel B. Lawson, and Panayiotis A. Koutentis
Journal of Magnetic Resonance, Available online 17 February 2023, 107406 – DOI: https://doi.org/10.1016/j.jmr.2023.107406
Athanassios K. Boudalis (équipe POMAM), Institut de Chimie de Strasbourg (UMR 7177).