HALOALKYL COMPLEXES OF THE TRANSITION-METALS .8. THE SYNTHESIS AND PROPERTIES OF [CPW(CO)3CH2X] (X = OCH3, CL, BR, I) AND THEIR REACTIVITY WITH NEUTRAL DONOR LIGANDS

The complexes [CpW(CO)3CH2X] (Cp = eta5-C5H5, X = Cl, Br, I) have been prepared. Their reactions with a series of tertiary phosphines, amine s, SMe2 and AsPh3 in THF, CH3CN, CH2Cl2 and MeOH have been investigate d. Two types of cationic products, namely the ylide complexes [CPW(CO) 3CH2L]+ and the disubstituted complexes [CpWL2(CO)2]+, were obtained, the outcome depending on the halide (X), the pK(a), cone angle and con centration of the ligand (L). and the solvent used. These variables we re also found to have significant influence on the reaction rates. The reactions of [CPW(CO)3CHX] with L were found to be significantly slow er than those of the analogous [CpFe(CO)2CH2X] complexes with the same ligands.