Conductor-insulator phase transitions were first reported by Verwey in 1939 in magnetite (Fe3O4)[1] below TV=125 K and were explained in terms of charge ordering in the octahedral sites of the magnetite lattice. However a full description of this phenomenon remains elusive. Attfield and co-workers[2] have recently shown that the transition is driven by the localization of electrons over Fe3 units in the magnetite sub-lattice. We have conducted a series of investigations of the Fe8 cluster, [Fe8O4(4-Cl-pz)12Cl4]z−, in various oxidation states, the aim being to shed light on the nature of mixed valence in the species where z &gt; 0.[3] The Fe4O4 cubane core shares many common features with magnetite, so we anticipate that this work may also shed light on the processes in the latter. A combination of magnetic susceptibility measurements, Mossbauer and XPS spectroscopies and density functional theory have provided important insights into the nature of mixed valency in [Fe8O4(4-Cl-pz)12Cl4]1− and, most recently, the dianion [Fe8O4(4-Cl-pz)12Cl4]2−. [1] E. J. W. Verwey, Nature (London), 1939,144, 327 [2] M. S. Senn, J. P. Wright & J. P. Attfield , Nature 2012,481, 173 [3] E. M. Zueva, R. Herchel, S. A. Borshch, E. V. Govor, W. M. C. Sameera, Ross McDonald,f John Singleton, Jurek Krzystek, Zdeněk Trávníček, Yiannis Sanakis, J. E. McGrady & R. G. Raptis, Dalton Trans., 2014,43, 11269

Electron localization and delocalization in mixed-valent Fe8(m-O)4 cores

251st National Meeting (2016)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.