Incorporation of Substitutionally Labile [VIII(CN)6]3−into Prussian Blue Type Magnetic Materials

A Prussian blue (PB) type material containing hexacyanovanadate(III), Mn(II)1.5[V(III)(CN)6].(0.30)MeCN (1), was formed from the reaction of [V(III)(CN)6](3-) with [Mn(NCMe)6](2+) in MeCN. This new material exhibits ferrimagnetic spin- or cluster-glass behavior below a Tc of 12K with observed magnetic hysteresis at 2 K (Hcr = 65 Oe and Mrem = 730 emu.Oe/mol). Reactions of [V(III)(CN)6](3-) with [M(II)(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 Fe(II)(0.5)V(III)[Fe(II)(CN)6].(0.85)MeCN (2), (NEt4)(0.10)Co(II)(1.5- a)V(II)a[Co(III)(CN)6]a [V(III)(CN)6](1-a)(BF4)(0.10).(0.35)MeCN (3), and (NEt4)(0.20)V(III)[Ni(II)(CN)4](1.6).(0.10)MeCN (4) compositions. Compounds 2-4 do not magnetically order as a consequence of diamagnetic cyanometalate anions being present, i.e., [Fe(II)(CN)6](4-), [Co(III)(CN)6](3-), and [Ni(II)(CN)4](2-). Incorporation of [V(III)(CN)6](3-) into PB-type materials is synthetically challenging because of the lability of the cyanovanadate(III) anion.