Adducts of Cyclotriphosphorus Complexes with Cyclopentadienyl Ruthenium Fragments: Synthesis, Solid State Structure and Solution Behaviour

Treatment of the cyclo-P3 complexes [(triphos)M(?3-P3)]- [triphos = 1,1,1-tris(diphenylphosphanylmethyl)ethane; M = Co (1), Rh (2)] with stoichiometric amounts of [CpRu- (CH3CN)2(PR3)]PF6 [R = Ph (3), Me (4), Cy (5)] in CH2Cl2 in the presence of CH3CN yields the bimetallic adducts [{(triphos)M}(?,?3:1-P3){CpRu(CH3CN)(PR3)}]PF6 [M = Co; R = Ph (6), Me (7), Cy (8); M = Rh; R = Ph, (9), Me (10), Cy (11)]. The rhodium derivatives 9 and 11, upon treatment with one equivalent of PMe3, form the complexes [{(triphos)Rh}(?,?3:1- P3){CpRu(PMe3)(PR3}]PF6 [R = Ph (12), Cy (13)]. On standing in CH2Cl2, the rhodium complexes 9 and 10 lose acetonitrile to yield compounds with the formula [{(triphos)Rh}(?,?3:1,1-P3){CpRu(PR3)}]PF6 [R = Ph (14), Me (15)]. All the compounds have been characterised by elemental analyses and, in solution, by 31P and 1H NMR spectroscopy. The 31P{1H} EXSY NMR spectroscopic data at different temperatures of 11 and 14 have highlighted the occurrence of independent dynamic processes that exchange both the triphos and the cyclo-P3 phosphorus nuclei. An X-ray structural investigation carried out on 6 has confirmed the occurrence of the ?,?3:1-ligating behaviour of the cyclo-P3 ligand.