An Iron(II) Spin‐Transition Compound with Thiol Anchoring Groups

The synthesis and characterisation of the complex [FeII(L)2](ClO4)2 [L = S‐(4‐{[2,6‐(Dipyrazol‐1‐yl)pyrid‐4‐yl]ethynyl}phenyl) ethanethioate] carrying both a spin‐transition core and acetyl‐protected terminal thiol groups is described. The compound exhibits a reversible, thermally driven solid‐state spin transition at 277 K with a hysteresis loop of ca. 8 K. The unique combination of the bistable spin‐transition property with thiol anchoring groups sets the basis for the investigation of the spin‐transition switching phenomenon at a single‐molecule level. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)