CUMULATED DOUBLE-BOND SYSTEMS AS LIGANDS .11. DINUCLEAR AND TRI-NUCLEAR IRON COMPLEXES RESULTING FROM THE REACTION OF [FE2(CO)9]WITH R-N=S=N-R(R=T-C4H9,4-MEC6H4) - CRYSTAL AND MOLECULAR-STRUCTURE OF [FE2(CO)6[RNC(O)S]], [FE3(CO)9(RNS)S] AND [FE3(CO)9(RN)S]

Reaction of RNSNR (R = t-C4H9, 4-MeC6H4) with (Fe2(CO)9[leads to the rupture of one or two NS double bonds as evidenced by the formation of a number of complexes containing RNS, RN and S fragments. In the case of R = t-C4H9 and 4-MeC6H4 the RNS fragment behaves as a four-electron donor ligand, with the NS bond still double, and as a six-electron donor ligand with the NS bond single, bridging two iron atoms in [Fe2(CO)7(RNS)] and [Fe2(CO)6(RNS)], respectively. Insertion of CO into the NS bond of [Fe2(CO)6(RNS)] yields [Fe2(CO)6{RNC(O)S}]; a crystal structure determination has been carried out for the product with R = 4-MeC6H4. Heating of the solid complex affords azotoluene, which is also isolated from the reaction mixtures. In the case of R = t-C4H9[Fe2(CO)6S2], [Fe3(CO)9S2] and [Fe3(CO)9(RNS)S] are also formed. A crystal structure determination of the last compound reveals a prismane type structure, in which both a six-electron donor RNS fragment and a four-electron donor S atom are linked to the three iron atoms. For R = 4-MeC4H4 a different trinuclear iron complex [Fe3(CO)9(RN)S] was isolated, and the structure was established by a crystal structure determination; a nitrene fragment (RN) as well as a S atom are both triply bridging to a non linear array of three iron atoms of the Fe3(CO)9 skeleton. © 1979.