THE REACTIONS OF BIS(ETA-CYCLOPENTADIENYL)DIHYDRIDOMOLYBDENUM AND BIS(ETA-CYCLOPENTADIENYL)TUNGSTEN WITH DIORGANYLMAGNESIUM REAGENTS

The compounds (C5H5)2MH2 (M = Mo, W) do not react with (C5H5)2Mg or (C5Me5)2Mg. The reaction of (C5H5)2MoH2 with (CH3)2Mg in the presence of tmeda, (CH3)2NCH2CH2N(CH3)2, has been monitored by H-1 NMR spectroscopy and yields Mg[Mo(H)(C5H5)2]2(tmeda). A similar compound, Mg[Mo(H)(C5H5)2]2(Et2O)2, is formed from (C5H5)2MoH2 and (CH3)2Mg or [C5H5MgCH3(Et2O)]2 in diethyl ether solution when no tmeda is present. These results are discussed in terms of ligand redistribution equilibria. (C5H5)2WH2 reacts too slowly with (CH3)2Mg for products to be isolated.