Synthesis, structures and some reactions of Ru(Ctriple bond; length of mdashCCtriple bond; length of mdashCFc)(PP)Cp (PP = dppm, dppe) and related compounds

The compounds Ru(Ctriple bond; length of mdashCCtriple bond; length of mdashCFc)(PP)Cp [PP = dppe (1), dppm (2)], have been obtained from reactions between RuCl(PP)Cp and FcCtriple bond; length of mdashCCtriple bond; length of mdashCSiMe3 in the presence of KF (1) or HCtriple bond; length of mdashCCtriple bond; length of mdashCFc and K[PF6] (2), both with added dbu. The dppe complex reacts with Co2(CO)6(L2) [L2 = (CO)2, dppm] to give 3, 4 in which the Co2(CO)4(L2) group is attached to the outer Ctriple bond; length of mdashC triple bond. The PPh3 analogue of 3 (5) has also been characterised. In contrast, tetracyanoethene reacts to give two isomeric complexes 6 and 7, in which the cyano-olefin has added to either Ctriple bond; length of mdashC triple bond. The reaction of RuCl(dppe)Cp with HCtriple bond; length of mdashCCtriple bond; length of mdashCFc, carried out in a thf/NEt3 mixture in the presence of Na[BPh4], gave [Ru{Ctriple bond; length of mdashCC(NEt3)double bond; length as m-dashCHFc}(dppe)Cp]BPh4 (8), probably formed by addition of the amine to an (unobserved) intermediate butatrienylidene [Ru(double bond; length as m-dashCdouble bond; length as m-dashCdouble bond; length as m-dashCdouble bond; length as m-dashCHFc)(dppe)Cp]+. The reaction of I2 with 8 proceeds via an unusual migration of the alkynyl group to the Cp ring to give [RuI(dppe){η-C5H4Ctriple bond; length of mdashCC(NEt3)double bond; length as m-dashCHFc}]I3 (9). Single-crystal X-ray structural determinations of 1, 2 and 4–9 are reported.