Synthesis, crystal structure and electronic properties of a 2Fe–2S complex with a bulky thiolato ligand, [NEt4]2[Fe2S2(SC6H2Me3-2,4,6)4]

Abstract

The complex [NEt₄]₂[Fe₂S₂(tmbt)₄](tmbt = 2,4,6-trimethylbenzenethiolate) was synthesised and its molecular structure determined. The crystal system is monoclinic with a= 15.241(6), b= 16.174(5), c= 16.768(6)Å, β= 135.84(2) and Z= 2, in space group P2₁/c. The Fe–S*(S*= inorganic sulphide) bond lengths are 2.195(6) and 2.204(6)Å and the Fe–S(C) are 2.299(8) and 2.318(6)Å. Steric congestion at the thiolate ligands causes rotation of two of the for Fe–S(C) torison angles from the stable staggered position to the restrictedly eclipsed position. The eclipsed Fe–S(C) has a wide Fe–S–C angle [112.35(76)°] with π-bond character and another staggered Fe–S(C) possesses a narrow Fe–S–C angle [104.95(64)°] with less π-bond character.