| Abstract
| - Cp2ZrH{(μ-H)2BC4H8} was prepared by hydride transfer to Cp2ZrCl2 and to Cp2ZrCl{(μ-H)2BC4H8}. The benzyl-substituted complexes Cp2Zr(CH2Ph){(μ-H)2BX} (X = C4H8, C5H10) were prepared from the reactions of Cp2ZrCl(CH2Ph) with [H2BC4H8]- and [H2BC5H10]-, respectively, which eliminate the side reaction found in the direct alkylation of zirconocene organohydroborate complexes.
- Three procedures were developed for the preparation of Cp2ZrH{(μ-H)2BC4H8}, 1. It can be prepared from thereaction of Cp2ZrCl2 with K[H2B2(μ-H)(μ-C4H8)2] in a 1:2 molar ratio; the reaction of Cp2ZrCl{(μ-H)2BC4H8}with K[H2B2(μ-H)(μ-C4H8)2] in a 1:1 molar ratio; and the reaction of Cp2ZrCl{(μ-H)2BC4H8} with LiH in a 1:1molar ratio. Although the first and second procedures imply the possible synthesis of Cp2Zr{(μ-H)2BC4H8}2, thiscompound is not formed. The preferential formation of 1 instead of Cp2Zr{(μ-H)2BC4H8}2 is probably due togreater thermal stability of 1. The benzyl-substituted compounds, Cp2Zr(CH2Ph){(μ-H)2BC4H8}, 2, and Cp2Zr(CH2Ph){(μ-H)2BC5H10}, 3, were prepared from the reactions of Cp2ZrCl(CH2Ph) with [H2BC4H8]- and[H2BC5H10]-, respectively. This preparative route eliminates the side reaction observed in the direct alkylation ofzirconocene organohydroborate complexes. The structures of 1−3 are also reported. Crystal data for 1: spacegroup Pnam, a = 9.836(2) Å, b = 10.186(2) Å, c = 13.393(3) Å, Z = 4. Crystal data for 2: space group Pbca,a = 8.3882(10) Å, b = 16.6669(10) Å, c = 27.0063(10) Å, Z = 8. Crystal data for 3: space group P21/n, a =9.674(2) Å, b = 14.047(2) Å, c = 14.512(3) Å, β = 102.53(2)°, Z = 4.
|
