Structure and properties of [CrIIIF(NCMe)5](BF 4)2·MeCN: A nonaqueous source of Cr IIIF2+ and a building block for new Prussian-blue-like magnetic materials

Abstract

[CrIIIF(NCMe)5](BF4)2· MeCN (1) was synthesized from a prolonged dissolution of [CrIII(NCMe) 6](BF4)3 in MeCN via fluoride abstraction from BF4-. Complex 1 exhibits a crystal field splitting, Δo, of 17 470 cm-1 and is a nonaqueous source of CrIIIF2+. The reaction of 1 with (NEt4) 3[CrIII(CN)6] formed a new Prussian-blue-like magnetic material of (NEt4)0.04[CrIIIF] 1.54[CrIII(CN)6](BF4) 0.12·0.10(MeCN) (2) composition. Complex 2 magnetically orders at a critical temperature, Tc, of 85 K and at 2 K exhibits magnetic hysteresis with a coercive field, Hcr, of 60 Oe and a remanent magnetization, Mrem, of 1880 emuOe/mol. © 2008 American Chemical Society.