Advances in Polynuclear Iron(II), Iron(III) and Cobalt(II) Spin‐Crossover Compounds

Abstract

Abstract This review describes the recent advances made in the syntheses, structures (including the use of synchrotron sources and variable‐temperature crystal structures and PXRD determinations of unit cell axes), magnetism, and photomagnetism of dinuclear and 1‐D chain spin‐crossover compounds of (primarily) iron(II), iron(III) and cobalt(II). It focuses on the work of the author's group and also includes a discussion of related work by other groups. In particular, the early and ongoing work by Kahn, Real, Gütlich and co‐workers on bipyrimidine‐bridged Fe II dinuclear materials has been extended by us and others to include many other new bridging and capping ligands. This had led to a fuller understanding of the spin transitions that involve HS‐HS, HS‐LS and LS‐LS pair states. The same is being achieved for new 1‐D chain materials, and notable advances include structural observation of ordered and disordered metal centres and corresponding spin states. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)