Reactions of bis(trifluoromethyl)phosphine with some organocobalt complexes
Abstract
The reaction of (CF3)2PH with the complex [Co2(CO)8] can lead either to [Co(CO)3{P(CF3)2}]2 or a polymeric red solid, depending on the presence or absence of solvent. With [Co(CO)3NO], the monomeric complex [Co(CO)2(NO){P(CF3)2H}] is formed in high yield which on pyrolysis gives [Co(CO)(NO){P(CF3)2}]2 and [Co(NO)2{P(CF3)2}]3. When (CF3)2PH is heated (80 °C) with a mixture of the complexes [Co(CO)3NO] and [Fe(CO)2(NO)2], [Co(CO)2(NO){P(CF3)2H}] is again produced. At higher temperatures, the products include [FeCo-(CO)(NO)3{P(CF3)2}2]3. A complex reaction occurs between (CF3)2PH and [(cp)Co(CO)2](cp =π-cyclopentadienyl), giving [Co(CO)3{P(CF3)2}]2, [(cp)Co{P(CF3)2}]2, and [(cp)Co(CO){P(CF3)2}Co(CO)3]; at the same time, reduction of the co-ordinated cp ligand to C5H6 is followed by addition of the phosphine or of hydrogen to give C5H7P(CF3)2 and C5H8 respectively as additional products. Spectroscopic data for all the complexes prepared are discussed and reaction mechanisms proposed.