Four aluminum, zinc, and aluminum/zinc heterometallic complexes 1-4 stabilized by o-phenylenediamine bridged poly (phenolato) ligands were synthesized and characterized. It was found that the reaction sequence has significant influence on the formation of the Al-Zn heterometallic complex AlZnL 1 Me (4), which was prepared through successive complexation of poly (phenol) with ZnEt 2 and AlMe 3 . The catalytic behaviors of complexes 1-4 for the ring-opening polymerization of cyclohexene oxide (CHO) were investigated, and the heterometallic complex 4 showed significantly enhanced activity (TOF up to 410 min À1 ). Kinetic study was conducted; the activation energy (E a ) for formation of PCHO using 4 was determined to be 58.0 ± 6.5 kJ mol À1 .

A series of lanthanide alkoxo complexes supported by ONNO salalen ligands were synthesized and characterized. A one-pot reaction of LH)) with LnCp 3 (THF) in a 1:1 molar ratio followed by the addition of 1 equiv of ROH (R = Bn, i Pr, and CF 3 CH 2 ), afforded the dimeric lanthanide alkoxo complexes 5), and [L 2 Yb(μ-OCH 2 CF 3 )] 2 (6) in good isolated yields. All these lanthanide complexes were characterized by elemental analysis and FT-IR spectroscopy. In addition, complex 1 has been characterized by NMR spectroscopy. Singlecrystal X-ray diffraction analysis of complexes 1, 2, 5, and 6 showed that these lanthanide alkoxo complexes are dimeric in the solid state. Complexes 1−6 showed good activity toward the homopolymerization of rac-butyrolactone (rac-BBL) to give atactic PHB, and ionic radii of central metals have profound influence on the polymerization. The polymerization behavior of L-lactide (L-LA) initiated by complex 2 was also explored. The kinetic study revealed that the polymerizations of rac-BBL and L-LA initiated by salalen lanthanide akoxide are first order for both the monomer and the initiator concentrations. Furthermore, it was found that complexes 1 and 2 showed good activity in the copolymerization of L-LA and rac-BBL, affording gradient copolymers.

The reactivities of benzoxazine functionalized amine bridged bis(phenol)s L n H 2 (n = 1-3) with rare earth metal complexes were explored, founding that both the aryl substituents of the ligand and the rare earth metals have profound influences on reaction outcomes. Reactions of L Keywords