Lithiation and alkylation reactions of the tri-phosphaferrocenes, [Fe(η5-P3C2tBu2)(η5-C5R5)], (R = H and Me): Crystal and molecular structures of the LiFe(η4-P2C2tBu2PnBu)(η5-C5Me5)2 dimer, [Fe(η4-P2C2tBu2PnBuMe)(η5-C5Me5)] and cis-[PtCl2(PMe3)Fe(η4-P2C2t

Treatment of the 1,2,4-tri-phosphaferrocenes, [Fe(η5-P3C2tBu2)(η5-C5R5)], (R = H; Me) with nBuLi leads to alkylation of one of the two adjacent ring phosphorus atoms to afford the corresponding lithium salts LiFe(η4-P2C2tBu2PnBu)(η5-C5R5)2 (R = H; Me). A single crystal X-ray diffraction study reveals that LiFe(η4-P2C2tBu2PnBu)(η5-C5Me5)2 exhibits an unusual dimeric structure in the solid state. Treatment of the lithium salts with MeI gives the monomeric zwitterion complexes [Fe(η4-P2C2tBu2PnBuMe)(η5-C5R5)], (R = H; Me). The molecular structure of [Fe(η4-P2C2tBu2PnBuMe)(η5-C5Me5)] and the platinum(II) complex cis-[PtCl2(PMe3)Fe(η4-P2C2tBu2PnBuMe)(η5-C5H5)] have also been determined by single crystal X-ray diffraction studies.