REACTIONS OF THE UNSATURATED DIHYDRIDES [MN2(MU-H)2(CO)6(MU-L2)] (L2 = (ETO)2POP(OET)2, PH2PCH2PPH2) WITH PHOSPHINES CONTAINING P-H BONDS

The unsaturated dihydrides [Mn2(mu-H)2(CO)6(mu-L2)] (L2 = (EtO)2POP(OEt)2 (tedip), Ph2PCH2PPh2 (dppm)) react readily at room temperature with PH3, PH2Cy or PHPh2 to give, after elimination of dihydrogen the corresponding saturated mu-hydrido mu-phosphido complexes [Mn2(mu-H)(mu-X)(CO)6(mu-L2)] (X = PH2, PHCy, PPh2) in high yield. Reactions with the dppm bridged dihydride are slower than those with the tedip bridged complex. A general reaction pathway is proposed. The structures of the new complexes are discussed on the basis of infrared and NMR (H-1, P-31) data, which in the case of [Mn2(mu-H)(mu-PHCy)(CO)6(mu-tedip)], reveal the presence of two isomers derived from the two possible orientations of the P-H hydrogen atom relative to the pyrophosphite ligand.