Preparation of cyclopentadienylrhodium(I) compounds with a dangling CH2C5H5 unit and their use as starting materials for the synthesis of hetero-bimetallic RhTi and RhZr complexes

A series of cyclopentadienylrhodium(I) complexes of the general composition [(η5-C5H4CH2C5H5)Rh(L)(L′)] (L=L′=C2H4, C8H14; L=PiPr3, L′=C2H4, CPh2, CCCPh2; L=SbiPr3, L′=CPh2) with a dangling CH2C5H5 unit at the π-bonded five-membered ring has been prepared from the corresponding rhodium(I) precursors and NaC5H4CH2C5H5 in THF. The compound [(η5-C5H4SiMe2C5H5)Rh(PhC≡CPh)(PiPr3)] has similarly been obtained and characterized by single-crystal X-ray diffraction analysis. Deprotonation of [(η5-C5H4CH2C5H5)Rh(L)2] and [(η5-C5H4CH2C5H5)Rh(L)(L′)] with either nBuLi or NaN(SiMe3)2 affords the corresponding anions which react with [(η5-C5H5)MCl3] (M=Ti, Zr) to give hetero-bimetallic RhTi and RhZr complexes with the dianion [(η5-C5H4)2CH2]2− as the bridging ligand. Treatment of the dinuclear tetrachloro compound [{CH2(η5-C5H4)2}{RhCl2(PiPr3)}{TiCl2(η5-C5H5)}], obtained from the related alkyne complex [{CH2(η5-C5H4)2}{Rh(PhC≡CPh)(PiPr3)}{TiCl2(η5-C5H5)}] and HCl, with methyllithium leads to the formation of the tetramethyl derivative [{CH2(η5-C5H4)2}{Rh(CH3)2(PiPr3)}{Ti(CH3)2(η5-C5H5)}]. On a similar route, the hetero-bimetallic dimethyl compound [{CH2(η5-C5H4)2}{Rh(CPh2)(CO)}{Zr(CH3)2(η5-C5H5)}] has been prepared.