A novel tripodal ligand with organosulfur alligator clips for depositionof tetrairon(III) single-molecule magnets on gold

A propeller-like tetrairon(III) complex functionalized with two 1,2-dithiolan-3-yl groups was synthesized and magnetically characterized. The compound has formula [Fe4(thioctic)2(dpm)6] and was specifically designed to be grafted on gold surfaces. It was prepared by reacting [Fe4(OMe)6(dpm)6] (Hdpm = dipivaloylmethane) with a new tripodal ligand, H3thioctic, obtained by esterification of 2,2-bis(hydroxymethyl)-propane-1,3-diol with (±)-α-lipoic acid (also known as thioctic acid). Direct current and alternating current magnetic measurements revealed single-molecule magnet behaviour with an effective anisotropy barrier of 14.0(1) K resulting from a high spin (S = 5) ground state and an easy-axis anisotropy.