Hydrolysis of Me3SiCH2 groups on a double-chelating bis(ferrocenediyl)diphosphine coordinating to a Pt(0) center

Abstract The double-chelating diphosphine ligand PCH 2 SiMe 3 -bridged [1.1]ferrocenophane ( 1 ), in which two phosphorus donor atoms are doubly linked with two ferrocene groups and with a Me 3 SiCH 2 group on each phosphorus center, was reacted with [Pt(PPh 3 ) 3 ] to form the tricoordinated Pt(0) complex [Pt( 1 )(PPh 3 )]. Refluxing of this complex with another equivalent of 1 in THF inadvertently containing traces of water was found to successively hydrolyze the four Me 3 SiCH 2 groups of [Pt( 1 ) 2 ] to eventually form [Pt( 2 ) 2 ], in which all the initial Me 3 Si groups of [Pt( 1 ) 2 ] were replaced with hydrogens. The molecular structure of [Pt( 2 ) 2 ], as determined by X-ray analysis, shows stereochemical congestion between the two ligands. Since hydrolysis in refluxing THF did not proceed at all for both the free ligand 1 and the Pt(II) complex [PtCl 2 ( 1 )], the stereochemical congestion of the Pt(0) complexes having two double-chelating diphosphine ligands is probably responsible for the observed hydrolysis.