Synthesis and characterization of transition metal stabilized carbocations of the types [CP*(CO)2Fe{μ-(CnH2n-1}M(CO)xCp]PF6 (x=2, M = Fe or Ru; x=3, M = W, Cp* = η5-C5(CH3)5; Cp = η5-C5H5; n=3-6) and [Cp(CO)2Ru{μ-(CnH2n-1)}W(CO)3Cp]PF6 (n=3-5) and the crystal structures of the complexes [Cp*(CO)2Fe(CH2)3Ru(CO)2Co], [Cp*(CO)2Fe(CH2)5Ru(CO)2Cp], [Cp*(CO)2Fe-(CH2)5W(CO)3Cp], and [Cp(CO)2Ru(CH2)5W(CO)3Cp]

The mixed-ligand complexes [Cp*(CO)(2)Fe(CH2)(n)M(CO)(x)Cp] (x = 2, M = Fe or Ru; x = 3, M = W, Cp* = eta(5)-C-5(CH3)(5); Cp = eta(5)-C5H5; n = 3-6), type I, react with one equivalent of the hydride abstractor Ph3CPF6 to give the transition metal-stabilized carbocation complexes [Cp*(CO)(2)Fe{mu-(CnH2n-1)}M(CO)(x)Cp]PF6. Similarly the new heterobimetallic complexes [Cp(CO)(2)Ru{mu-(CnH2n-1)}W(CO)(3)Cp], type II, react with Ph3CPF6 to give the carbocation complexes [CP(CO)(2)Ru{mu-(CnH2n-1)}W(CO)(3)Cp]PF6. Spectroscopic data show that hydride abstraction selectively takes place from the methylene group beta to the metal atom attached to the Cp* ligand in type I complexes. In type II complexes, the reaction is totally metalloselective with hydride abstraction occurring at the CH2 beta to the ruthenium metal centre. All products have been characterized by IR, H-1, C-13 NMR spectroscopy and elemental analysis. H-1 and C-13 NMR data clearly show that in the carbocation complexes one metal is sigma-bonded to the alkanediyl carbocation while the other is bonded to the cationic end in a eta(2)-fashion forming a chiral metallacylopropane type structure. The molecular structures of the cationic metallacyclic complexes [Cp*(CO)(2)Fe{mu-(C3H5)}Fe(CO)(2)Cp]PF6 [E.O. Changamu, H.B. Friedrich, M. Rademeyer, Acta Crystallogr., Sect. E 62 (2006) m442.] and [Cp*(CO)(2)Fe(mu-C3H5)Ru-(CO)(2)Cp]PF6 [H.B. Friedrich, E.O. Changamu, M. Rademeyer, Acta Crystallogr., Sect. E 62 (2006) m405.] have been confirmed by single crystal X-ray crystallography and reported elsewhere. The structures of the precursor complexes [Cp*(CO)(2)Fe(CH2)(3)Ru-(CO)(2)Cp] (1), [Cp*(CO)(2)Fe(CH2)(5)Ru-(CO)(2)Cp] (2), [Cp*(CO)(2)Fe(CH2)(5)W(CO)(3)Cp] (3), and [Cp(CO)(2)Ru (CH2)(5)W(CO)(3)Cp] (4), have been confirmed by single crystal X-ray crystallography. The structure of [Cp*(CO)(2)Fe(CH2)(3)Ru(CO)(2)Cp] is compared with that of its corresponding cationic complex, [Cp*(CO)(2)Fe(mu-(C3H5)}Ru(CO)(2)Cp]PF6. (c) 2007 Elsevier B.V. All rights reserved.