Zirconium bis-indenyl compounds. Synthesis and X-ray crystallography study of 1- and 2-substituted bis(R-indenyl)zirconium dichloride metallocenes

摘要

A series of 1- and 2-substituted indenylligandswere prepared and used in the synthesis of [1-R-Ind]~ZrCI2 [R = Me (2b), Et 4b), 'Pr (5b), 'Bu (6b), SiMe-, (8b), Ph (lOb). Hz (12b). I-Naph (14b)] and [2-R-Ind]~ZrCI~ [R = Me (Ib), Et (3b), SiMe-, (7b), Ph 9b), Hz (lIb), l-Naph (IJb)] metallocenes. An X-ray crystallographic study of 4b and lOb showed the complexes to be the racemic liastereomers (4b. both the R.R and S,S-enantiomers and lOb, the S,S-enantiomer). The X-ray data together with NMR spectral lata revealed that the size of the substituent influenced the orientation the two indenyl ligands of the metallocenes. The 4b liastereomers are both found to crystallize with their ecthyl groups syn (bis-central) with respect to each other whereas the larger >henyl groups in lOb results in an anti (bis-Iateral) orientation of the indenyl ligands.