摘要
A series of sodium 2-arylimino-8-quinolates,C1-C8,differing in both the nature of the aryl and quinolate substituents,was prepared and characterized by ^(1)H/^(13)C NMR spectroscopy and elemental analysis.Their X-ray structures reveal multimetallic assemblies adopting a variety of structural cores all based on Na-O repeat units:cubic and tetrametallic for C1,C2 and C4,hexagonal prismatic and hexametallic for C3 and C5,and for tetrametallic C7’a core resembling a cyclooctatetraene-type tub-shape.In the presence of BnOH,C1-C8 exhibit good activities towards the ring-opening polymerization(ROP)of rac-lactide,affording amorphous polylactides with broad molecular weight distributions.Furthermore,the substituent variation within the ligand frame of C1-C8 affects the catalytic activities of the ROP with the least sterically hindered system,C1,yielding the highest conversion.
基金
supported by the National Natural Science Foundation of China(no.51273202 and U1362204)
the Chinese Academy of Sciences for a Visiting Scientist Fellowship.
