NEW η-ALLYL η-CYCLOPENTADIENYLCOBALT CATIONS

Article abstract of DOI:10.1016/S0022-328X(00)86754-6

is a good precursor for the preparation of some new cationic complexes as the iodide can easily be replaced; thus addition of PEt3 to the iodo-complex (R=H) gives ⁺.The reactions of (R=H or 2-Me) with AgBF4 give solutions containing the coordinatively unsaturated species ⁺.The presence of traces of water leads to the formation of ⁺.The addition of monodentate ligands L=PEt3, PPh3, AsPh3, SbPh3, CNCH3 and bidentate ligands L-L=Ph2PCH2CH2PPh2(dppe) and o-C6H4(AsMe2)2(diars), gives, respectively mononuclear ⁺ and binuclear ligand-bridged <(2-Me-η-C3H4)(η-C5H5)Co-L-L-Co(2-Me-η-C3H4)(η-C5H5)>²⁺ complexes.Crystals of ^+- are monoclinic, space group P2₁/c, with a 7.858(3), b 10.262(4), c 15.078(4) Angstroem, β 98.36(1)^o.The molecular structure contains the cobalt atom bonded to planar 2-Me-allyl and cyclopentadienyl substituents, which are almost parallel with the H2O molecule in a staggered conformation with respect to the 2-Me group.