Ring-Opening Polymerization of Lactide with Zr Complexes of {ONSO} Ligands: From Heterotactically Inclined to Isotactically Inclined Poly(lactic acid)
作者:Ayellet Stopper、Jun Okuda、Moshe Kol
DOI:10.1021/ma2023364
日期:2012.1.24
prepared by a two-step synthesis. Their [ONSO}Zr(OtBu)2] complexes formed as single diastereomers with different degrees of fluxionality that depended on the substitution pattern of the two phenolate rings. The complexes were active in polymerization of l-lactide and rac-lactide. The tacticity of the poly(lacticacid) prepared fromrac-lactide changed gradually fromheterotactically inclined through atactic
通过两步合成制备了ONSO}型配体新家族的六个成员-四齿-二阴离子亚胺-硫代双(酚盐)配体。它们的[ONSO} Zr(O t Bu)2 ]配合物形成为具有不同通量度的单个非对映异构体,取决于两个酚盐环的取代方式。该配合物在1-丙交酯和外消旋丙交酯的聚合反应中具有活性。由外消旋-丙交酯制备的聚乳酸的立构规整度从杂规倾斜到无规倾斜逐渐变为等规倾斜。最灵活的配合物和最刚性的配合物分别给出了最高程度的异规整度和全同规整度。