ZIRCONOCENE HYDRIDES WITH COORDINATED SULFONATES

The synthesis of Cp2ZrH(OSO2R) and Cp2ZrBH4(OSO2R) (R = Me, Bu-1, (CF2 )(7)CF3, Ph, p-tolyl, p-C6H4Cl, m-C6H4CF3, m-C6H4NO2 (ZrBH4 only), 3,5 -C6H4(CF3)(2)) is described. The Hammett constants of the aryl substit uents correlate well with the B-11 NMR shift in Cp2ZrBH,(OSO2R) (R = a ryl sulfonate). Hexene insertion into the Zr-H bond of Cp2ZrH(OSO2CF3) (1) is fast and reversible: reaction of Cp(2)Zrhexyl(OSO2CF3) with 2- butyne gives Cp2ZrCMe=CHMe(OSO2CF3) and 1-hexene. Treatment of 1 with styrene leads to a kinetically controlled mixture of Cp2ZrCH2CH2Ph(OSO 2CF3) and Cp2ZrCHCH3Ph(OSO2CF3) that equilibrates with a first-order r ate law. The rate is independent of added styrene. Olefin insertion in to the Zr-C bond was not found.