TRAPPING OF A PHENYL GROUP BY A RUTHENIUM CLUSTER DURING DEPHENYLATION OF COORDINATED CH2(PPH2)(2) (DPPM)

Pyrolysis of {Ru-3(mu-dppm)(CO)(9)}(n)(dppa) (n = 1 or 2) afforded mu( 3)-eta(1):eta(2):P-C2PPh2)(mu-PPh2)(Ph)(CO)(6), containing an Ru-3 cha in bridged by a dephenylated dppm ligand and by C2PPh2 and PPh2 ligand s derived from the dppa ligand. The phenyl group from the dppm ligand has been trapped by one of the Ru atoms to give a rare example of a cl uster-bound sigma-Ph group. The molecular structure of a(1),eta(2)-CCH P(O)Ph-2}(mu-PPh2)(mu-dppm)(CO)(6), obtained on one occasion from the mono-cluster complex, is also described. (C) 1997 Elsevier Science S.A .