Cyano-Bridged Fe(II)–Cr(III) Single-Chain Magnet Based on Pentagonal Bipyramid Units: On the Added Value of Aligned Axial Anisotropy

• Published in: Journal of the American Chemical Society Vol. 140; no. 24; pp. 7698 - 7704
• Main Authors: Pichon, Céline, Suaud, Nicolas, Duhayon, Carine, Guihéry, Nathalie, Sutter, Jean-Pascal
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 20.06.2018
• Subjects: Chemical Sciences; or physical chemistry; Theoretical and
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/jacs.8b03891

A cyano-bridged Fe­(II)–Cr­(III) single-chain magnet designed to ensure a parallel orientation of the axial anisotropy of the building units is reported. This ferromagnetic chain compound consists of a pentagonal bipyramid Fe­(II) complex with Ising-type anisotropy and a dicyanide Cr­(III) complex interlinked through their apical positions. It is characterized by an energy gap for the magnetization reversal of Δeff/k B = 113 K and exhibits magnetic hysteresis with a coercive field of 1400 Oe at 2 K which positions this compound among the very few examples of SCMs with spin reversal barriers above 100 K. The quite remarkable performances of this single-strand SCM are attributed to the alignment of the local anisotropy axes, which is supported by ab initio modeling. A discrete Cr2Fe complex based on the same building units and behaving as a SMM in zero field is also reported.