Wenjuan Zhang, Shaofeng Liu, Wenhong Yang
Nov 5, 2012
Citations
0
Influential Citations
38
Citations
Journal
Organometallics
Abstract
Stoichiometric reactions of YCl3(THF)3 with potassium 2-((arylimino)methyl)quinolin-8-olates or 2-(1-(arylimino)ethyl)quinolin-8-olates in THF solution gave the mononuclear LYCl2(DMSO)2 complexes 1–5 in the presence of DMSO and a representative dinuclear complex 6 in the absence of DMSO. All yttrium complexes were fully characterized by NMR measurements and elemental analysis, and the crystal structures of complexes 1 and 4–6 were determined by single-crystal X-ray diffraction. The structures indicate coordination number seven around the yttrium center and pentagonal bipyramidal geometries. The complexes all feature diapical YCl2 moieties and one tridentate organic ligand in the equatorial plane. Upon reaction of the yttrium precatalysts 1–6 with LiCH2Si(CH3)3 alone or with LiCH2Si(CH3)3 together with BnOH, the ring-opening polymerization (ROP) of e-caprolactone (e-CL) occurred with high efficiency. Depending on conditions, the ROP of e-CL produced polycaprolactone with narrow molecular distribution and i...