Synthesis Of Magnetic Nanoparticles-supported Biden-tate Phosphine Palladium(Ⅱ) Complex And Its Catalytic Properties In Carbonylative Polycondensation

This thesis consists of three parts:Part one: we started with the commercially available magnetic nanoparticles Fe₃O₄ , which reacted with the tetraethyl silicate（TEOS） to prepare silica-coated Fe₃O₄ （Fe₃O₄ @SiO₂ ）. The latter was treated with the triethoxysilyl-functionalized bidentate phosphine ligand and followed by the reaction with Pd Cl₂ to give a novel magnetic nanoparticles-supported bidentate phosphine palladium（Ⅱ） complex（Fe₃O₄ @SiO₂ -2P-Pd Cl₂）. The new heterogeneous palladium catalyst was characterized by elemental analysis, transmission electron microscopy（TEM） and energy dispersive spectroscopy（EDS）. Then, we applied this catalyst in the carbonylative polycondensation of 1,3-diiodobenzene, 4,4’-oxydianiline and CO（1atm） to prepare aromatic polyamides. It was found that this heterogeneous palladium catalyst has as high catalytic activity as homogeneous Pd Cl₂（PPh3）2 and can be recycled several times without significant loss of activity.Part two: Firstly, several aromatic diiodides containing ether ketone linkages were prepared by simple procedures, including 4,4’-bis（3-iodobenzoyl）diphenyl ether, 4,4’-bis（3-iodophenoxy）benzophenone, and 1,4-bis[4-（3-iodophenoxy）benzoyl]naphthalene. Then, we investigated the carbonylative polycondensation of aromatic diiodides containing ether ketone linkages, aromatic diamines with CO（1atm） using Fe₃O₄ @ SiO₂ -2P-Pd Cl₂ as catalyst. The polymers obtained were characterized by FT-IR, 1H NMR, 13 C NMR, etc. and their properties were also determined. The results showed that this heterogeneous palladium catalyst exhibited high catalytic activity and could be recycled several times without significant loss of activity and high molecular weight（Mn = 21402⁶7671） polymers could be prepared. These polymers were soluble in most of the polar solvents such as NMP, DMF and DMAc, and had Tgs of 174-233 oC, tensile strengths of 72.8⁸2.6 MPa, Young’s moduli of 1.95⁶.99 GPa and elongations to break of 2.4⁷.7%. Besides, these polymer films had good light transmission performance, and the light transmittances（λ = 600 nm） were almost above 80%.Part three: Firstly, several novel aromatic diamines monomers containing 2,6-diphenyl-4-arylpyridine moieties were prepared by simple procedures, including 4,4’-[4-（4-（trifluoromethyl）phenyl）pyridine-2,6-diyl]dianiline, 4,4’-（4-（[1,1’-biphenyl]-4-yl）pyridine-2,6-diyl）dianiline, 4,4’-[4-（naphthalen-2-yl）pyridine-2,6-diyl]dianiline, 4,4’-[4-（naphthalen-1-yl）pyridine-2,6-diyl]dianiline. Then, we investigated the carbonylative polycondensation of these aromatic diamines monomers with aromatic diiodides containing ether ketone linkages under CO（1 atm） in the presence of Fe₃O₄ @SiO₂ -2P-Pd Cl₂, affording a series of novel aromatic polyamides. The structures of these polymers were characterized by FT-IR, 1H NMR, 13 C NMR, etc. and their properties were also determined. The results indicated that this heterogeneous palladium catalyst showed high catalytic activity and could be recycled several times without significant loss of activity and high molecular weight（Mn = 27944⁸0244） polymers could be prepared. These polymers were soluble in most of the polar solvents such as NMP, DMF and DMAc, and had Tgs of 224-257 oC, tensile strengths of 86.4¹13.7 MPa, Young’s moduli of 2.42⁶.99 GPa and elongations to break of 2.9⁶.8%. In addition, these polymer films had good light transmission performance, and the light transmittances（λ = 600 nm） were almost above 80%.