Synthesis, structure and properties of syn-bis(μ-N-methylpiperidine-4-thiolate tricarbonyl iron)

The reaction of Fe3(CO)12 with N-methyl-4- mercaptopiperidine gives the title compound. Crystals are monoclinic, space group P21/c with a = 12.922(2), b = 14.784(5), c = 13.607(2) Å, β = 112.41(1)°. With Z = 4 the calculated density is 1.49 g cm-3. Solution of the structure by direct methods led to a final weighted R factor of 0.029 for 2270 independent reflections. The FeFe bond length is 2.534(1) Å and the S···S distance of 2.940(1) suggests bonding interactions. By heating upon reflux in toluene during 10 h, the IR spectrum of the chromatographed solution indicates the syn isomer formation. The reaction with CH3I and HClO4 produces the methylation and protonation, respectively, of the nitrogen atoms of the piporidine rings giving rise to the formation of the [Fe(μ-(CH3)2NC5H9S)(CO)3]2I2·2H2O and [Fe(μ-HCH3NC5H9S)(CO)3]2·H2O·CH3OH compounds. © 1986.