Permanent Porosity in the Room-Temperature Magnet and Magnonic Material V(TCNE) 2 .

Materials that simultaneously exhibit permanent porosity and high-temperature magnetic order could lead to advances in fundamental physics and numerous emerging technologies. Herein, we show that the archetypal molecule-based magnet and magnonic material V(TCNE) ₂ (TCNE = tetracyanoethylene) can be desolvated to generate a room-temperature microporous magnet. The solution-phase reaction of V(CO) ₆ with TCNE yields V(TCNE) ₂ ·0.95CH ₂ Cl ₂ , for which a characteristic temperature of T * = 646 K is estimated from a Bloch fit to variable-temperature magnetization data. Removal of the solvent under reduced pressure affords the activated compound V(TCNE) ₂ , which exhibits a T * value of 590 K and permanent microporosity (Langmuir surface area of 850 m ² /g). The porous structure of V(TCNE) ₂ is accessible to the small gas molecules H ₂ , N ₂ , O ₂ , CO ₂ , ethane, and ethylene. While V(TCNE) ₂ exhibits thermally activated electron transfer with O ₂ , all the other studied gases engage in physisorption. The T * value of V(TCNE) ₂ is slightly modulated upon adsorption of H ₂ ( T * = 583 K) or CO ₂ ( T * = 596 K), while it decreases more significantly upon ethylene insertion ( T * = 459 K). These results provide an initial demonstration of microporosity in a room-temperature magnet and highlight the possibility of further incorporation of small-molecule guests, potentially even molecular qubits, toward future applications.
Competing Interests: The authors declare no competing financial interest.
(© 2023 The Authors. Published by American Chemical Society.)