학술논문
Reaction of B(C6F5)3 with zirconium and hafnium benzyl diene complexes. The crystal and molecular structures of Cp″Zr(C6F5){η4-CH2CMeCHCHB(C6F5)2} and [Cp″Hf(2,3-Me2C4H4)(OEt2)][PhCH2B(C6F5)3] [Cp″ 4;= 4;1,3-(SiMe3)2C5H3]
Document Type
Article
Author
Source
Journal of the Chemical Society, Dalton Transactions; May 21, 1999, Vol. 1999 Issue: 10 p1663-1668, 6p
Subject
Language
ISSN
03009246
Abstract
The zirconium and hafnium diene complexes Cp″MCl(η4-CH2CMeCR1CH2) react with benzylmagnesium chloride to give the benzyl complexes Cp″M(η4-CH2CMeCR1CH2)(CH2Ph) (M 4;= 4;Zr, R1 4;= 4;Me or H; M 4;= 4;Hf, R1 4;= 4;Me) which react with B(C6F5)3 selectively under benzyl abstraction to give the zwitterionic products Cp″M(η4-diene){ηn-PhCH2B(C6F5)3}. The zirconium derivative exists as a mixture of two isomers which interchange via ring-flipping of the diene ligand, whereas the Hf compound is rigid. The isoprene analogue Cp″Zr(CH2CMeCHCH2){PhCH2B(C6F5)3} decomposes at room temperature under C–H activation and C6F5 migration from boron to zirconium to give toluene and the structurally characterised boryldiene complex Cp″Zr(C6F5){CH2CMeCHCHB(C6F5)2}. In the hafnium (but not zirconium) complexes, the [PhCH2B(C6F5)3]– anion is displaced by CH2Cl2. The addition of diethyl ether leads to the ionic compound [Cp″Hf(2,3-Me2C4H4)(OEt2)]+[PhCH2B(C6F5)3] which was characterised by X-ray diffraction.