Half-Sandwich Iron Complexes With A Silanol-Functionalized Cyclopentadienyl Ligand

The complexes [(X)R2Si-C5H4](OC)(2)Fe-R' (X = OMe, H; R = Me, iPr, Ph; R' = Me, SiMe3) (4a-e) are synthesized from the corresponding silyl-functionalized iron anions Li[Fe(CO)(2)(C5H4-SiR2X)] (X = H, OMe; R = Me, iPr, Ph) (2b-e) by treatment with methyl iodide or chlorotrimethylsilane, respectively. Hydrolysis of (XMe2Si-C5H4)(OC)(2)Fe-R (X = OMe, Cl; R = Me, SiMe3) (4a, 5a, b) or reaction of (HMe2Si-C5H4)(OC)(2)Fe-R [R = Me (4b), SiMe3 (4c)] with Co-2(CO)(8) followed by treatment with H2O yields the silanols [(HO)Me2Si-C5H4](OC)(2)Fe-R [R = Me (6a), SiMe3 (6b)]. 6a,b undergo condensation reactions with chlorodimethylsilane or titanocene dichloride, respectively, to yield the iron fragment-substituted disiloxanes (HMe2SiOMe2Si-C5H4)(OC)(2)Fe-R [R = Me (7a), SiMe3 (7b)] or the heterosiloxanes [(Cl)Cp2TiOMe2Si-C5H4](OC)(2)Fe-R [R = Me (Sa), SiMe3 (Sb)].