| One mixed-valent organolanthanide complex and four divalent organolanthanide complexes supported by amine bisphenolate and amine-amine bisphenolate ligands respectively were first synthesized and well characterized. One cationic trivalent organolanthanide complex was also synthesized and characterized. The molecular structure of the six noval complexes pressed here were determined by X-ray diffraction. The catalytic behaviors of these organolanthanide complexes for polymerization of ε-CL were investigated. 1. Reactions of Ln[N(SiMe3)2]2(THF)2 (Ln=Sm, Yb, Eu) with nitrigon-bridged biphenolate ligands L1, L2(L1 = nBuN(CH2-2-HO-3,5-C6H2(tBu)2)2, L2 = Me2NCH2CH2N(CH2-2-HO-3,5-C6H2(tBu)2)2 respectively in 1:1 molar ratio gave one mixed-valent product for Sm, [nBuN(CH2-2-O-3,5-C6H2(tBu)2)2]4Sm( Ⅲ)2Sm( Ⅱ) 1, and four divalent product for Yb, [nBuN(CH2-2-O-3,5-C6H2(tBu)2)2]Yb(THF)3 2 ,{[nBuN(CH2-2-HO-3,5-C6H2(tBu)2)2)2]Eu}2 3 ,[Me2NCH2CH2N(CH2-2-O-3,5-C6H2(tBu)2)2)2]Yb(THF)2 4 和{[ Me2NCH2CH2N(CH2-2-O-3,5-C6H2(tBu)2)2)2]Eu}2,5. All these complexes were characterized by elemental analysis, IR spectroscopy, 1H NMR spectroscopy, and the molecular structures of complexes 1, 2, 4 and 5 were further determined by X-ray diffraction. 2. Reactions of Sm(OC6H2tBu2-2,6-Me-4)3(THF)2 with AgBPh4 gave cationic trivalent product (ArO)2Sm(DME)2.BPh4 6 which was characterized by elemental analysis, IR spectroscopy, 1H NMR spectroscopy and X-ray diffraction. 3. The polymerizations of ε-CL initiated by complexes 3, 4 and 5 were investigated. It was found that the divalent complex of [Me2NCH2CH2N(CH2-2-O-3,5-C6H2(tBu)2)2)2]Yb(THF)2 showed very high activity even higher than that for the corresponding complex supported by unbridged phenolate ligand. 4. The catalytic activity of 6 for ring-opening polymerization of ε-CL was also examined and the results show 6 exhibits very high activity even higher than that of corresponding natural (ArO)3Sm. |
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