Study on synthesis and characterization of a novel pyridine imide ligated rare earth metal complex C₂₈H₅₁N₂Ln (THF)_n(CH₂ SiMe₃)₃ (Ln = Sc, Y) and its catalytic performance in polymerization of isoprene

We simply synthesized the pyridine imine rare earth trialkyl Figures (2, 3) by using the isofold scandium trialkyl complex Sc₃(THF)_2.5(CH₂SiMe₃) and the Yttrium trialkyl complex Y(THF)_2.5(CH₂SiMe₃)₃ with the pyridine imine derivative ligand (1: C₂₈H₅₁N₂Sc (THF) (CH₂SiMe₃)₃; 2: C₂₈H₅₁N₂Y(THF)_0.625(CH₂SiMe₃)₃. In situ, nuclear magnetic resonance (NMR) showed that for pyridine imine rare earth trialkyl Figures (2, 3), different feed ratios of borate [Ph₃C] [B(C₆F₅)₄] to catalyst and different feed sequences of borate and alkyl aluminum can produce different catalytic active species. These catalytic active species can realize high activity (4.08 × 10⁴g·mol_Sc⁻¹·h⁻¹), high selectivity, and narrow molecular weight distribution (1.4) polymerization of conjugated diene such as isoprene.