0000000000445224
AUTHOR
Yasunori Yoshida
Pyrrolide-imine benzyl complexes of zirconium and hafnium: synthesis, structures, and efficient ethylene polymerization catalysis
Abstract A series of pyrrolyl-imines HL1–6 was prepared by the condensation of pyrrole-2-carboxyaldehyde with different amines. The reaction of 2 equiv of pyrrolyl-imine with tetrabenzyl complexes of hafnium and zirconium M(CH2Ph)4 (M=Hf or Zr) gave dibenzyl complexes (L3–6)2M(CH2Ph)2, which were characterized by NMR spectroscopy and crystal structure analysis. NMR spectra of the complexes with secondary alkyl substituents at the imine nitrogen (isopropyl: 3a, 4-tert-butylcyclohexyl: 4a and 4b) suggest that rapid racemization between Δ and Λ configurations occurs in solution on the NMR time scale. The complexes with pyrrolide-imine ligands with a tertiary alkyl group such as tert-butyl (5a …
Efficient ethylene polymerisation catalysis by a cationic benzyl hafnium complex containing pyrrolide-imine ligandsElectronic supplementary information (ESI) available: experimental and spectroscopic details. See http://www.rsc.org/suppdata/dt/b2/b209582c/
A dibenzyl hafnium(IV) complex containing pyrrolide-imine chelate ligands was synthesized and investigated as an ethylene polymerisation catalyst.