TRANSITION-METAL SILYL COMPLEXES .50. SYNTHESIS, STRUCTURE AND REACTIVITY OF TRIHYDRIDOSILYL AND TRIHYDRIDOSTANNYL COMPLEXES L3FEH3(ER3) (E=SI, SN)

Photochemical reaction of (CO)2(dppe)Fe(H)(SiR3) with HSiR3 (SiR3 = Si(OMe)3, Si(OEt)3, SiMe3, SiMe2Ph, SiPh3) yields the trihydrido silyl complexes (CO)(dppe)FeH3(SiR3). The analogous complexes (PR'Ph2)3FeH3(ER3) are prepared by reaction of the H-2-complexes (PR'Ph2)3FeH2(H2) with HER3 (ER3 = SiMe3, SiMe2Ph, SiMePh2, SiPh3, Si(Me2)OSi(Me2)H, SnPh3, SnEt3). Additional derivates of (CO)(dppe)FeH3(SiR3) (SiR3 = SiMePh2) and (PR'Ph2)3FeH3(SiR3) (SiR3 = Si(OMe)3, SiH2Ph, SiHPh2, Si(OEt)3, SiMePhCl) are accessible by silane exchange starting from (CO)(dppe)FeH3(SiMe3) and (PR'Ph2)3FeH3(SiMe3). (PBuPh2)3FeH3(SiMePh2) was also prepared from (PBuPh2)3FeH2(N2) and HSiMePh2, and (PBuPh2)3FeH3(SnMe3) from (PBuPh2)3FeH2(H2) and Me3SnCl. The complex (PBuPh2)3FeH3(SnMe3) crystallizes as a toluene solvate in the cubic space group I4BAR3d and shows crystallographically imposed C3-symmetry. The complexes (CO)2(dppe)Fe(H)(SiR3) and (PR'Ph2)3FeH3(ER3) are highly dynamic in solution. Low temperature NMR measurements and the E, Fe, H coupling constants strongly indicate that the exchange mechanism involves eta2-HER3 ligands.