| Summary: | 博士 === 國立中興大學 === 化學系所 === 96 === Thirteen novel complexes [(EDBP-H)Na(THF)]2 (1a), [(EDBP-H)Na(Et2O)]2 (1b), [EtZn(EDBP)Na(Et2O)]2 (2), [Na(EDBP)]2Zn(THF)3 (3), [Na(EDBPN)]2Mg(THF)4 (4), [(Et2O)Na(EDBP)Mg(TMAP)]2 (5), [Na(EDBP)Li)]3(Et2O) (6), [(Et2O)Na(EDBP)Li]2Li[N(SiMe3)2] (7), (dppe)Pt(MBS-O) (9a), (dppe)Pt(MBS-NH) (9b), [TBSC]2Li4[THF]4 (11), [TBSC]2Na4[THF]4 (12) and [TBSC]2K4[THF]4 (13) have been synthesized and fully characterized. Complexes 1a, 3, 4, 5, 6, 7, 9a, 9b and 11 have been determined by X-ray single crystal diffraction method. Bimetallic complexes 3, 4 and 6 exhibit well-controlled catalyzed properties in the ring-opening polymerization (ROP) of L-lactide (LLA). The tunable activity could be performed by mixing two different metals forming bimetallic complexes to promote or demote the activity. The Pt complex 9b displays “living” property as an initiator in the ROP of Nξ-carbobenzyloxy-L-lysine N-carboxyanhydride (Z-Lys-NCA), however, complex 9a failed to initiate the ROP reaction of Z-Lys-NCA monomer. Combining the catalytic results of complexes 9a and 9b, the proton migration is the key step in the mechanism for the polymerization reaction of Z-Lys-NCA. Complex 11 shows the “controlled” property in the catalytic ROP reaction of LLA with narrow PDIs and medium to high stereoselectivity in catalytic ROP of rac-lactide. The obtained prepolymers were converted into the polylactides (PLAs) with amino group (-NH2) in the end chain which was used as a macroinitiator for the preparation of polylactides block polypeptide copolymers.
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