An {Fe16} barrel: Synthesis, structural and magnetic characterisation of an {Fe8} ring and its dimer

The synthesis, structure and magnetic properties of an octametallic iron(III) ring is reported. Alternate edges of the ring are bridged by a hydroxide and two pivalates, or by one pivalate and two phenoxides. By addition of biphenol to the reaction a hexadecametallic iron(III) cage can be made where the 16 metals are arranged in two linked {Fe8} rings. The rings are staggered with respect to one another, and lie on the vertices of an octagonal anti-prism. Magnetic studies on the octametallic ring allows exchange parameters to be obtained. Similar studies on the {Fe16} barrel shows the exchange interactions within the rings to be similar, with a significant paramagnetic impurity present.

Graphical abstractThis paper reports a very unusual {Fe16} cage based on two linked octagonal rings. The resulting structure is a octagonal anti-prism. Magnetic measurements are reported on this compound and on a parent {Fe8} ring.Figure optionsDownload full-size imageDownload as PowerPoint slide