New Mono- and Polynuclear Iron Silylene and Stannylene Complexes

The mono- and dinuclear stannylene reagents [Sn(μ-NtBu)2SiMe2] (4) and [Sn(OtBu)(μ-OtBu)]2 (6) were reacted with the amine-stabilized bis(dimethylamino)silylene complex [Fe{Si(NMe2)2(NHMe2)}(CO)4] (1), but no insertion or substitution product was detected.
However, reaction of the hydridoiron silyl complex [HFe{Si(OMe)3}(CO)3(dppm-P)] with 4
afforded the ion pair 7, in which the Fe−H proton has migrated to a nitrogen atom of 4, and
with 6 by initial transfer of the Fe−H proton to a tBuO group to give the bimetallic stannylene
complex [(OC)3{(MeO)3Si}Fe(μ-dppm)Sn(OtBu)] (8), in which the Sn atom has a distorted-trigonal-pyramidal coordination. The tin(II) compound 6 also reacted with [Fe2(CO)9] to afford
the new tin−iron complex [Fe(CO)4Sn(OtBu)(μ-OtBu)]2 (9), which contains a central Sn2O2
planar core. In contrast, reaction of 4 with [Fe2(CO)9] yielded [(OC)4Fe{μ-Sn(μ-NtBu)2SiMe2}]2
(10), which contains a central, planar Sn2Fe2 core. All compounds were characterized by
multinuclear NMR spectroscopy, and the molecular structures of 1, 8·THF, and 9 (triclinic
(9a) and monoclinic (9b) forms) were determined by X-ray diffraction.