Cyclic Hydroborate Complexes of Metallocenes III. Syntheses and Structures of Zirconocene Boracyclohexane Derivatives Cp<sub>2</sub>Zr(X){(μ-H)<sub>2</sub>BC<sub>5</sub>H<sub>10</sub>} (X = H, CH<sub>3</sub>, H<sub>2</sub>BC<sub>5</sub>H<sub>10</sub>)
作者:Fu-Chen Liu、Jianping Liu、Edward A. Meyers、Sheldon G. Shore
DOI:10.1021/ic9803917
日期:1998.6.1
In reactions of Cp2ZrCl(mu-H)(2)BC5H10}, 1, with LiH, Cl- is replaced to produce Cp2ZrH(mu-H)(2)BC5H10}, 2. Reaction of 1 with K[H2BC5K10] yields Cp2Zr(mu-H)(2)BC5H10}(2), 4 The methyl-substituted compound Cp2Zr(CH3)(mu-H)(2)BC5H10}, 3, is prepared from the reaction of Cp2ZrCl(CH3) with K[H2BC5H10]. The synthetic route for the preparation of 3 prevents side reactions that occur in the direct alkylation of zirconocene organohydroborate complexes. Proton NMR spectra of 2 at elevated temperatures indicate that intramolecular hydrogen exchange occurs among Zr-H-B hydrogens, terminal H on Zr, and Cp hydrogens. The structures of 2, 3, and 4 are reported. Crystal data for 2: space group Abm2 (No. 39), a = 11.423(2) Angstrom, b = 14.138(3) Angstrom, c = 9.025(5) Angstrom, Z = 4. Crystal data for 3: space group Pbca (No. 61), a = 8.469(4) Angstrom, b = 16.828(9) Angstrom, c = 21.897(8) Angstrom, Z = 8. Crystal data for 4: space group C2/c (No. 15), a = 16.222(7) Angstrom, b = 9.434(2) Angstrom, c = 13.131(5) Angstrom, beta = 102.97(3)degrees, Z = 4.