Synthesis and solid-state structural characterization of bis (thiocyanatemercury)tetracarbonyliron

Abstract

The bis (thiocyanatemercury)tetracarbonyliron, [Fe(CO) 4(HgSCN) 2], was prepared from [Fe(CO) 5] and Hg(SCN) 2, and studied by IR spectroscopy and X-ray diffraction. The compound crystallizes in the tetragonal space group I4, 1/ a. The unit cell, with dimensions of a = 13.778(3), c = 13.234(3) Å, V = 2512.3(9) Å 3, contains four molecules. The iron atom is octahedrally coordinated by four carbonyl groups and two mercury atoms in cis positions. The coordination of the mercury atoms is distorted square-planar, since, besides mercury-iron and mercury—sulphur bonds, there are also mercury—mercury and mercury-nitrogen interactions. The FeHg distance is 2.506(5)Å and the HgFeHg angle is 78.0(1)°.