SYNTHESES AND CHARACTERIZATION OF OSPT2(MU-CO)(MU-I)(2)(CO)(2)(PPH3)(3) AND OS-2(MU-I)(2)(CO)(6-N)(PPH3)(N)(N=1, 2) IN THE SOLID-STATE AND SOLUTION

The reaction of Os-2(CO)(6)(mu-I)(2) with Pt(dba)(PPh3)(2) or Pt(PhCCP h)(PPh3)(2) affords three novel complexes Os-2(CO)(6-n)(mu-I)(2)(PPh3) (n) [n = 1 (2), n = 2 (4)] and OsPt2(CO)(2)(mu-CO)(mu-I)(2)(PPh3)(3) ( 3). 2 and 3 were characterized by X-ray analysis. The isotopically pur e Os-187(2)(CO)(6)(mu-I)(2) was also used in the synthesis of the corr esponding complexes 2'-4' to study their structures in solution. It wa s determined that the OsPt2(CO)(2)(mu-CO)(mu-I)(2)(PPh3)(3) cluster is symmetric in solution whereas in the solid-state it has an asymmetric structure which may be explained by the different disposition of the mu-I ligands around the OsPt2-triangle. (1)J(Os-Os), (2)J(Os-P), (1)J( Pt-Pt), (1)J(Pt-P), and (2)J(P-P) coupling constants have been determi ned. (C) 1997 Elsevier Science S.A.