Magnetic Ordering (<i>T</i><sub>c</sub> = 90 K) Observed for Layered [Fe<sup>II</sup>(TCNE<sup>•-</sup>)(NCMe)<sub>2</sub>]<sup>+</sup>[Fe<sup>III</sup>Cl<sub>4</sub>]<sup>-</sup> (TCNE = Tetracyanoethylene)

[Fe(TCNE)(NCMe)<sub>2</sub>][FeCl<sub>4</sub>] is isolated from the reaction of TCNE and FeCl<sub>2</sub>(NCMe)<sub>2</sub> and orders as a ferrimagnet below 90 K and is the initial member of a new class of magnets. It is the first metal−TCNE magnet with direct bonding between metal ion and [TCNE]<sup>•-</sup> whose structure has been determined, and it possesses a novel planar μ<sub>4</sub>-[TCNE]<sup>•-</sup> spin coupling unit bonded to four Fe<sup>II</sup>'s, with an axial pair of MeCNs. The [Fe<sup>III</sup>Cl<sub>4</sub>]<sup>-</sup> anion occupies sites between the [Fe<sup>II</sup>(TCNE<sup>•-</sup>)(NCMe)<sub>2</sub>]<sup>+</sup> layers. [Fe(TCNE)(NCMe)<sub>2</sub>][FeCl<sub>4</sub>] has a coercive field of 1730 Oe and a remnant magnetization of 7500 emuK/mol at 50 K.