HOMO-BRIDGED AND HETERO-BRIDGED MIXED-VALENCE DINUCLEAR COMPLEXES WHICH CONTAIN THE FRAGMENT RH(C6F5)(3)

The reaction of the anionic mononuclear rhodium complex [Rh(C6F5)(3)Cl (Hpz)](-) (Hpz=pyrazole, C3H4N2) with methoxo or acetylacetonate compl exes of Rh or Ir led to the heterodinuclear anionic compounds [(C6F5)( 3)Rh(mu-Cl)(mu-pz)M(L(2))] [M = Rh, L(2)=cyclo-octa-1,5-diene, COD (1) , tetrafluorobenzobarrelene, TFB (2) or (CO)(2) (4); M=Ir, L(2)=COD (3 )]. The complex [Rh(C6F5)(3)(Hbim)](-) (5) has been prepared by creati ng [Rh(C6F5)(3)(acac)](-) with H(2)bim (acac=acetylacetonate; H(2)bim= 2,2'-biimidazole), Complex 5 also reacts with Rh or Ir methoxo, or wit h Pd acetylacetonate, complexes affording the heterodinuclear complexe s [(C6F5)(3)Rh(mu-bim)M(L(2))](-) [M=Rh, L(2)=COD (6) or TFB (7); M=Ir , L(2)=COD (8); M=Pd, L(2)=eta(3)-C3H5 (9)]. With [Rh(acac)(CO)(2)], c omplex 5 yields the tetranuclear complex [{(C6F5)(3)Rh(mu-bim)Rh(CO)(2 )}(2)](2-). Homodinuclear Rh-III derivatives [{Rh(C6F5)(3)}(2)(mu-L)(2 )](2-) [L(2)=OH, pz (11); OH, (SBU)-B-t (12); OH, SPh (13); bim (14)] have been obtained by substitution of one or both hydroxo groups of th e dianion [{Rh(C6F5)(3)(mu-OH)}(2)](2-) by the corresponding ligands. The reaction of [Rh(C6F5)(3)(Et(2)O)(x)] with [PdX(2)(COD)] produces n eutral heterodinuclear compounds [(C6F5)(3)Rh(mu-X)(2)Pd(COD)] [X=Cl ( 15); Br (16)]. The anionic complexes 1-14 have been isolated as the be nzyltriphenylphosphonium (PBzPh(3)(+)) salts.