Incorporation of Substitutionally Labile [VIII(CN)6]3− into Prussian Blue Type Magnetic Materials
journal contributionposted on 07.04.2008, 00:00 by Kendric J. Nelson, Joel S. Miller
A Prussian blue (PB) type material containing hexacyanovanadate(III), MnII1.5[VIII(CN)6]·0.30MeCN (1), was formed from the reaction of [VIII(CN)6]3− with [Mn(NCMe)6]2+ in MeCN. This new material exhibits ferrimagnetic spin- or cluster-glass behavior below a Tc of 12 K with observed magnetic hysteresis at 2 K (Hcr = 65 Oe and Mrem = 730 emu·Oe/mol). Reactions of [VIII(CN)6]3− with [MII(NCMe)6]2+ (M = Fe, Co, Ni) in MeCN lead to either partial (M = Co) or complete (M = Fe, Ni) linkage isomerization, resulting in compounds of FeII0.5VIII[FeII(CN)6]·0.85MeCN (2), (NEt4)0.10CoII1.5−aVIIa[CoIII(CN)6]a[VIII(CN)6]1−a(BF4)0.10·0.35MeCN (3), and (NEt4)0.20VIII[NiII(CN)4]1.6·0.10MeCN (4) compositions. Compounds 2–4 do not magnetically order as a consequence of diamagnetic cyanometalate anions being present, i.e., [FeII(CN)6]4−, [CoIII(CN)6]3−, and [NiII(CN)4]2−. Incorporation of [VIII(CN)6]3− into PB-type materials is synthetically challenging because of the lability of the cyanovanadate(III) anion.