Synthesis And Characterization Of Homoleptic Aryloxy And Sulfonamido Lanthanide(la/Gd) Complexes And Their Catalytic Behavior

In this thesis, a series of homoleptic aryloxy and sulfonamido rare earth metal complexes were designed and synthesized based on ortho amino phenol and N-substituted para toluene sulfonamide ligands. The complexes obtained were characterized by elemental analysis, nuclear magnetic resonance(NMR), infrared spectrum and X-ray single crystal diffraction. The catalytic properties and mechanism of the complexes on the ring-opening polymerization of ?-caprolactone have also been studied. The research work includes the following two parts:Part one: synthesis and characterization of homoleptic aryloxy rare earth metal complexes and their application as catalyst in the polymerization of ?-caprolactone.Five nitrogen containing aryloxy ligands [2,4-tBu2-6-CH2NMe2-PhOH(HA), 2,4-tBu2-6-CH2NEt2-PhOH(HB), 2,4-tBu2-6-CH2Py-PhOH(HC), 2-tBu-4-Me-6-CH2Py-PhOH(HD), 4-tBu-2,6-(CH2Py)2-PhOH(HE)] were obtained by Mannich reaction. Ten homoleptic aryloxy rare earth metal complexes [LaA3(2a), GdA3(2b), LaB3(2c), GdB3(2d), LaC3(2e), GdC3(2f), LaD3(2g), GdD3(2h), LaE3(2i), GdE3(2j)] were synthesized by amine elimination reaction of aryloxy ligands with Ln[N(SiMe3)2]3(Ln = La, Gd) in a ratio of 3:1. X-ray single crystal structure analysis showed that complexes 2c and 2e both are octahedral mononuclear metal complexes. The catalytic properties and mechanism of aryloxy rare earth metal complexes on the ring-opening polymerization of ?-caprolactone have been studied and discussed as well.Part two: synthesis and characterization of homoleptic sulfonamido rare earth metal complexes and their application as catalyst in the polymerization of ?-caprolactone.Five sulfonamide ligands [TsNHiPr, TsNHtBu, TsNHPh, TsNHPhMe-p, TsNHPhOMe-p] were obtained by amidation reaction of paratoluensulfonyl chloride and primary amine. Ten homoleptic sulfonamido rare earth metal complexes [(TsNiPr)3La(3a),(TsNiPr)3Gd(3b),(TsNtBu)3La(3c),(TsNtBu)3Gd(3d),(TsNPh)3La(3e),(TsNPh)3Gd(3f),(TsNPhMe-p)3La(3g),(TsNPhMe-p)3Gd(3h),(TsNPhOMe-p)3La(3i),(TsNPhOMe-p)3Gd(3j)] were synthesized by amine elimination reaction of sulfonamide ligands with Ln[N(SiMe3)2]3(Ln = La, Gd) in a ratio of 3:1. X-ray single crystal structure analysis showed that complex 2c is a pentagon double cone dinuclear metal complex. The catalytic properties and mechanism of sulfonamido rare earth metal complexes on the ring-opening polymerization of ?-caprolactone have been studied and discussed as well.