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Updated: Jun 21, 2025
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Published on: June 9, 2023
Self-Assembled Tetranuclear Square Complex of Chromium(III) Bridged by Radical Pyrazine: A Molecular Model for
Dandan Lou1, Nathan J Yutronkie1, Itziar Oyarzabal2,3
1Univ. Bordeaux, CNRS, CRPP, UMR 5031, F-33600 Pessac, France.
Abstract:
The attractive electronic properties of metal-pyrazine materials─electrical conductivity, magnetic order, and strong magnetic coupling─can be tuned in a wide range depending on the metal employed, as well as its ligand-imposed redox environment. Using solvent-directed synthesis to control the dimensionality of such systems, a discrete tetranuclear chromium(III) complex, exhibiting a rare example of bridging radical pyrazine, has been prepared from chromium(II) triflate and neutral pyrazine. The strong antiferromagnetic interaction between CrIII (S = 3/2) and radical pyrazine (S = 1/2) spins, theoretically estimated at about -932 K, leads to a thermally isolated ST = 4 ground state, which remains the only populated state observable even at room temperature.
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