SYNTHESIS, CHARACTERIZATION AND SOME REACTIONS OF ORGANOMETALLIC COMPLEXES CONTAINING BRIDGING DITHIONITE LIGAND

Article abstract of DOI:10.1016/S0022-328X(00)88559-9

A novel organometallic dithionite complex, <η⁵-C5H5Fe(CO)2SO2>2, in which the -S(O)2S(O)2- ligand bridges two iron atoms has been synthesized by four methods: treatment of Na<η⁵-C5H5Fe(CO)2> with a large excess of SO2, insertion of SO2 into <η⁵-C5H5Fe(CO)2>2SO2, reaction of <η⁵-C5H5Fe(CO)2>2Hg with SO2 and irradiation of <η⁵-C5H5Fe(CO)2>2 in the presence of SO2.Of the four preparative routes, photolysis proved to be the most general one and also afforded the analogous complexes 2 (M = Mn or Re) from 2 and SO2.However, irradiation of <η⁵-C5H5M(CO)3>2 (M = Mo or W) and SO2 yielded <η⁵-C5H5M(O)S>2 instead.The new dithionite complexes were characterized by elemental analysis and infrared and NMR spectroscopy.Photolysis of each of <η⁵-C5H5Fe(CO)2SO2>2 and 2 resulted in loss of SO2 to produce <η⁵-C5H5Fe(CO)2>2SO2 plus <η⁵-C5H5Fe(CO)2>2 and 2, respectively.The complex <η⁵-C5H5Fe(CO)2SO2>2 reacted with alkyl iodides (RI) on heating to give η⁵-C5H5Fe(CO)2I and η⁵-C5H5Fe(CO)2, and underwent alkylation by (C2H5)3OPF6 to yield η⁵-C5H5Fe(CO)2, among other products.However, no reductive cleavage of <η⁵-C5H5Fe(CO)2SO2>2 occurred with KH.