Synthesis Of Aminophenoxy Lanthanide Complexes And Their Catalytic Behavior For The Ring-opening Polymerization Of1,4-dioxan-2-one

Fourteen lanthanide complexes were synthesized and structurally characterizedusing2kinds of aminophenoxy ligands3,5-But2-2-(OH)C6H2CH2-8-NH-(2-Me-C9H5N)([NO]1H2) and3,5-But2-2-(OH)C6H2CH2-NH-(2,4-Cl2-C6H3)([NO]2H2) as ancillary ligands. Thecatalytic behavior of lanthanide amides supported by phenoxy(quinolinyl)amideligand for the polymerization of1,4-dioxan-2-one (PDO) and the copolymerization ofPDO and-CL were expored. The catalytic behavior of neutral phenoxyamidolanthanide amido complexes supported by3,5-But2-2-(OH)C6H2CH2-NH-(2,4-Cl2-C6H3) for the polymerization of rac-lactidewas also studied. The main results are as following:1. Amine elimination reactions of Ln[N(SiMe3)2]3with [NO]1H2in a1:1molarratio in hexane gave homoleptic lanthanide complexes[NO]13Ln2(Ln=Yb(1), Sm(2),Nd(3), La(4)). Complexes1-4were characterized by elemental analysis, IR, singlecrystal X-ray diffraction, and NMR spectroscopy in the case of complex4.2. The amine elimination reaction of [NO]1H2with Eu[N(SiMe3)2]3in a4:3molar ratio afforded the mixed-valent trinuclear complex L4EuIII2EuII(5). Complex5has been well characterized by elemental analysis, IR and single crystal X-raydiffraction.3. Amine elimination reactions of Ln[N(SiMe3)2]3with [NO]2H2in a1:2molarratio in toluene gave homoleptic lanthanide complexes {H[NO]2}3Ln (Ln=Yb(6),Sm(7)). Complexes6,7were characterized by elemental analysis, IR and singlecrystal X-ray diffraction.4. Amine elimination reactions of Ln[N(SiMe3)2]3(-Cl)Li(THF)3with [NO]2H2 in a1:1molar ratio in toluene gave the neutral phenoxyamido lanthanide amidocomplexes {[NO]2LnN(SiMe3)2}2(Ln=Yb(8), Y(9)，Sm(10)). Complexes8-10werecharacterized by IR, elemental analysis, single crystal X-ray diffraction and NMRspectroscopy in the case of complex9. Structural determination revealed thatcomplexes8-10have an unsolvated dimeric structure.5. Amine elimination reactions of Nd[N(SiMe3)2]3(-Cl)Li(THF)3with [NO]2H2in a0.8:1molar ratio in toluene did not give the neutral phenoxyamido neodymiumamide {[NO]2NdN(SiMe3)2}2, but the bimetallic neodymium-lithium amido complex[NO]22Nd[N(SiMe3)2][Li(THF)]2(11) was isolated. So the simple amine eliminationreactions of lithium aminophenolate[2,4-Cl2C6H3NHCH2(3,5-tBu2C6H2-2-O)Li(THF)]2withLn[N(SiMe3)2]3(-Cl)Li(THF)3in THF in a2:1molar ratio at-10C were used to getthe bimetallic lanthanide-lithium amido complexes [NO]22Nd[N(SiMe3)2][Li(THF)]2(11) and [NO]22La[N(SiMe3)2][Li(THF)]2(12). Complexes11,12were characterizedby IR, elemental analysis, single crystal X-ray diffraction in the case of complexe11and NMR spectroscopy in the case of complexe12.6. Amine elimination reactions of Ln[N(SiMe3)2]3(-Cl)Li(THF)3with [NO]2H2in a1:2molar ratio in toluene gave the lithium-lanthanide complexes[NO]2Y{H[NO]2}2Li(THF)(Ln=Y(13), Sm(14)). Complexes13,14werecharacterized by IR, elemental analysis, single crystal X-ray diffraction and NMRspectroscopy in the case of complexe13.7. The behavior for the ring-opening polymerization of PDO initiated bylanthanide amides supported by phenoxy(quinolinyl)amide ligand[3,5-But2-2-O-C6H2CH2N-8-C9H6N]Ln[N(SiMe3)2](DME)(Ln=Sm, Nd, La) wasstudied. These lanthanide amides can catalyze the ring-opening polymerization ofPDO at60oC with high activity. It was also founded that[3,5-But2-2-O-C6H2CH2-N-C9H6N]Nd[N(SiMe3)2](DME) can well initiate thecopolymerization of PDO and-CL under mild conditions. The obtained copolymersshowed the properties of random copolymer. 8. The behavior for the ring-opening polymerization of rac-lactide initiated bylanthanide Complexes {[NO]2LnN(SiMe3)2}2(Ln=Yb(8), Y(9)， Sm(10)) wasinitially studied. It was founded that they can initiate the polymerization of rac-lactideat room temperature with moderate activity and middle stereoselectivity, and the valueof Pr varys from0.70to0.78.