Multidentate β-Ketoiminato Nickel, Palladium And Copper Complexes:Synthesis,Characterization And Vinyl Polymerization Of Norbornene

In this dissertation, a series of novel nickel, palladium and copper complexes bearing multidentate β-ketoimine ligands have been synthesized and characterized. The crystal structures of ten complexes have been confirmed by the single crystal X-ray diffraction analysis. These complexes are applied to catalyze vinyl polymerization of norbornene (NB). The catalytic behaviors towards NB are investigated in detail under the polymerization parameters such as Al/M ratio (M=Ni, Pd, Cu), reaction time, reaction temperature and monomer concentration. At the same time, the structures and properties of polynorbornene (PNB) are characterized. The major research works are summarized as follows:1. A tridentate [N,N,O] β-ketoiminato palladium complex has been synthesized and characterized, and the crystal structure has been determined by single crystal X-ray diffraction analysis. In the presence of methylaluminoxane (MAO), the complex displays excellent catalytic activities for NB vinyl polymerization. Under the optimal polymerization conditions, catalytic activity is up to2.18×108gPNB/(molpd·h). The obtained PNBs are insoluble in chlorobenzene solvent, and the viscosity average molecular weights of the polymers not measured.2. Two novel tridentate [O,N,O] di-nuclear nickel complexes2a and2b have been synthesized and characterized. The crystal structures of ligands and complexes have been confirmed by single crystal X-ray diffraction analysis. Upon activation with MAO, the nickel complexes as catalysts for the vinyl polymerization of NB are investigated. The results reveal that the nickel complexes can efficiently catalyze NB polymerization to generate high molecular weight polymers. Complex2b based on phenoxy-imine ligand exhibit higher activities than complex2a bearing β-ketoimine ligand due to the unpliant framework of the phenoxy-imine ligand. Under the optimal reaction conditions, the catalytic activities are up to49.88×106gPNB/(mol2a·h) and53.5l×106gPNB(mol2b·h), respectively.3. The series of nickel, palladium and copper complexes bearing tetradentate [O,N,N,O] β-ketoiminato ligands have been synthesized and characterized, and the crystal structures of the ligands and most of the complexes have been determined by single crystal X-ray diffraction analysis. After activation with MAO, the nickel complexes (3a-3c) can be effectively catalyze NB polymerization and obtain high molecular weight polymers. In addition, two palladium complexes3e and3f also exhibit good catalytic activities, but the resulting polymers show poor solubility in chlorobenzene. Copper complexes (3d-3f) only traces of polymers are generated. Complexes3b and3f are investigated for the polymerization of NB with various polymerization parameters. Under the optimal polymerization conditions, the highest catalytic activities are up to2.45×106gPNB/(molNi·h) and9.97×106gPNB/(molpd·h)...