New ferrocenylmethylphosphines – Preparation, characterisation and coordination chemistry of PH(CH2Fc)2, P(CH2Fc)3 [Fc = Fe(η5-C5H5)(η5-C5H4)] and their derivatives

The new ferrocenylmethylphosphines PH(CH2Fc)2 (1) [Fc = Fe(η5-C5H5)(η5-C5H4)] and P(CH2Fc)3 (2) and the phosphonium salt [P(CH2Fc)3(CH2OH)]I (3) were synthesised from P(CH2OH)3 and [FcCH2NMe3]I. [P(CH2Fc)(CH2OH)3]Cl (4) was obtained from P(CH2Fc)(CH2OH)2, CH2O and HCl. The new phosphines and phosphonium salts were fully characterised by NMR and IR spectroscopy and MS. [Mo(CO)6] reacts with 1 to give [Mo(CO)5{PH(CH2Fc)2}] (5) in high yield, but attempts to employ 2 as a ligand failed. The reaction of [P(CH2Fc)3(CH2OH)]I (3) and [PH(CH2Fc)3]I (obtained in situ from 3 and Na2S2O5) with [WI2(CO)3(NCMe)2] gave the complex salts [P(CH2Fc)3(CH2OH)][WI3(CO)4] (6) and [PH(CH2Fc)3][WI3(CO)4] (7), respectively. [P(CH2Fc)4]I (8) was synthesized from PH2CH2Fc and [FcCH2NMe3]I. Crystal structures were obtained for 1, 3–8.

Graphical abstractNew ferrocenylmethylphosphines PH(CH2Fc)2 (1) [Fc = Fe(η5-C5H5)(η5-C5H4)], P(CH2Fc)3 (2), and phosphonium salts [P(CH2Fc)3(CH2OH)]I (3), [P(CH2Fc)(CH2OH)3]Cl (4) and [P(CH2Fc)4]I (8) were prepared. Reactions with transition metal complexes showed that 2 is too bulky to coordinate in octahedral complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide