Hydrido-silyl complexes,Part VIII. Photochemical reaction of [Fe(CO)3H(PR′3)SiR3] with silanes,HSiR3: Influence of PR′3 and SiR3 on formation and structures of bis-silyl complexes [Fe(CO)3(PR′3)(SiR3)2]

Summary Upon u.v. irradiation of Fe(CO)₄(PR ₃ )] with HSiR₃ (HSiR₃ = HSiMePh₂, PR₃ = PPh₃; HSiR₃ = HSiMe₂Cl, PR₃ = PPh₃ or PMe₂Ph; HSiR₃ = HSiMeCl₂, PR₃ = PPh₃, PMePh₂, PMe₂Ph or PMe₃; HSiR₃ = HSiCl₃, PR₃ = PPh₃, PMePh₂, PMe₂Ph, PMe₃ or PBu ₃ ⁿ ) the corresponding hydridosilyl complexes Fe(CO)₃H(PR₃)SiR₃] are formed. The complexes have themer configuration with acis disposition of the hydride and the silyl ligands. Prolonged irradiation with an excess of silane results in the formation of bis-silyl complexes Fe(CO)₃(PR₃)(SiR₃)₂], if electron density at the metal is not too high. Thus, Fe(CO)₃H(PPh₃)SiMePh₂] and Fe(CO)₃-H(PMe₂Ph)SiMe₂Cl] can be obtained but not the corresponding bis-silyl complexes. Most bis-silyl complexes are obtained asmer-isomers with acis-arrangement of the silyl ligands. Only for Fe(CO)₃(PR₃)(SiCl₃)₂] with small phosphine ligands (PR₃ = PMe₃ or PMe₂Ph) is thefac-isomer formed.Part VII of this series, ref. (1).