Dicarbonyl(pyrazine-1,3-dithiolato-κ2S,S′)bis(trimethylphosphane-κP)iron(II)

The title compound, [Fe(C4H2N2S2)(C3H9P)(2)(CO)(2)], was obtained as a mononuclear by-product during the treatment of [Fe-2(mu-S2C4N2H2)(CO)(6)] in excess trimethylphosphane. The Fe atom is six-coordinated by two thiolate S atoms, two phosphane P atoms and two carbonyl C atoms in a distorted octahedral geometry. The average Fe-C(O) distance (1.771 angstrom) is relatively shorter than that of its parent hexacarbonyldiiron compound, and differs by 0.511 angstrom from the average Fe-P(Me)(3) distance. The five-membered FeC2S2 chelate ring plane is close to being perpendicular to the P/Fe/P plane [86.5 (2)degrees].