A zirconocene(IV) chloro-alkyl and dialkyl containing chiral α-cabon atoms, [Zr(η-C5H5)2(R*)(X)][R*= CH(SiMe3)C6H4Me-o, X = Cl or R*]: synthesis, stereoisomerism, and d1 reduction products

Abstract

Reactions of [Zr(η-C₅H₅)₂Cl₂] with LiR*(tmeda)[R*= CH(SiMe₃)C₆H₄Meo, tmeda = Me₂NCH₂CH_2–NMe₂] under different conditions yield [Zr(η-C₅H₅)₂(Cl)R*](3), and the diastereoisomers meso-(2a) and rac-(2b)[Zr(η-C₅H₅)₂R*₂], the latter of which is prepared from (2a) by photolysis or thermolysis; [Zr(η-C₅H₅)₂R*(thf)_x](x= 0–2) is obtained and characterised by e.s.r. spectroscopy in tetrahydrofuran (thf) solution by (a) Na [C₁₀H₈]–thf reduction of complex (2a), (2b), or (3)[via the radical anion of (3), itself accessible by reversible one-electron reduction of (3)], or (b) Na–Hg–thf-reduction of (3).