Synthesis of ansa-Dimethylsilanediyl−dicyclopentadienyl− zirconacyclopent-3-yne, Me2Si(η5-C5H4)2Zr(η4-H2C4H2), and Its Reactions with Ni(0) and B(C6F5)3
摘要:
The synthesis and reactions of ansa-dimethylsilanediyl-dicyclopentadienyl-zirconacyclopent-3-yne, Me2Si(eta(5)-C5H4)(2)Zr(eta(4)-H2C4H2) (7), are described. Complexation by Ni(0) complexes gives an external coordination of the triple bond and formation of the complex Me2Si(eta(5)-C5H4)(2)Zr[mu(eta(4)-H2C4H2)]Ni(PPh3)(2) (8), representing a mu-"cis"-complexation of 1,2,3-butatrienes, which is described and compared with the coordination of similar complexes. The reaction of complex 7 with B(C6F5)(3) results in ring opening of the 1-zirconacyclopent-3-yne and formation of the zwitterionic complex [Me2Si(eta(5)-C5H4)(2)Zr](+)-CH2CCCH2-[B-(C6F5)(3)] (9), with the but-2-yne-1,4-diyl ligand bridging the zirconocenium center and the formed boranate. All complexes were characterized by X-ray analysis.