The Library
Non-planar co-ordination of C-2-symmetric biaryl-bridged Schiff-base ligands: well expressed chiral ligand environments for zirconium
Tools
Tools
Tools
UNSPECIFIED (1999) Non-planar co-ordination of C-2-symmetric biaryl-bridged Schiff-base ligands: well expressed chiral ligand environments for zirconium. JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS (22). pp. 4069-4076. ISSN 0300-9246
Full text not available from this repository.Abstract
The C-2-symmetric Schiff-base proligand (H2L1) synthesized by condensation of 2,2'-diamino-6,6'-dimethylbiphenyl and 3,5-di-tert-butylsalicylaldehyde reacted in its deprotonated form with [MCl4(THF)(2)] (M=Zr or Hf) to give [(MLCl2)-Cl-1]. The molecular structures of these complexes show that they belong to the hitherto unknown cis-cis class of quadridentate Schiff-base complex. Most importantly, the two chloride ligands occupy mutually cis co-ordination sites in a well expressed chiral ligand environment that is structurally analogous to that of the ansa-metallocenes. Alkylations of the zirconium complex were unsuccessful, but an unstable complex [ZrL1(CH2Ph)(2)] was synthesized from H2L1 and Zr(CH2Ph)(4). Amido complexes [ZrL1(NR2)(2)] (R=Me or Et; R-2=HBut) were synthesized by substitution reactions of [(ZrLCl2)-Cl-1] and by reaction of H2L1 with Zr(NR2)(4). The reactions of [ZrL1(NR2)(2)] (R=Me or Et) with SiH(OEt)(3) and SiMe3Cl gave [ZrL1(OEt)(2)] and [(ZrLCl2)-Cl-1] respectively. The reaction of [(ZrLCl2)-Cl-1] with LiOPh gave [ZrL1(OPh)(2)]. The molecular structure of the latter confirms that it also has the cis-cis structure and also indicates the presence of edge-face arene interactions between the phenoxide ligands and the salicylidene units. The reaction of [(ZrLCl2)-Cl-1] with LiAlH4 in pyridine (py) led to reduction in situ of the imine groups and elimination of both chloride ligands to give a complex containing the quadruply deprotonated reduced form of L-1, i.e. [ZrL2(py)(2)]. This complex is also formed by reaction of H4L2 with Zr(NR2)(4) in pyridine.
| Item Type: | Journal Article |
|---|---|
| Subjects: | Q Science > QD Chemistry |
| Journal or Publication Title: | JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS |
| Publisher: | ROYAL SOC CHEMISTRY |
| ISSN: | 0300-9246 |
| Date: | 1999 |
| Number: | 22 |
| Number of Pages: | 8 |
| Page Range: | pp. 4069-4076 |
| Publication Status: | Published |
| URI: | http://wrap.warwick.ac.uk/id/eprint/13965 |
Data sourced from Thomson Reuters' Web of Knowledge
Actions (login required)
 |
View Item |
