Zirconium complexes of bipyrrolidine derived salan ligands for the isoselective polymerisation of rac-lactide.
نویسندگان
چکیده
Herein we report the synthesis and characterisation of a series of Zr(IV) 2,2'-bipyrrolidine-salan derived complexes and their exploitation for the ring opening polymerisation of rac-lactide to afford highly isotactically enriched polymers.
منابع مشابه
Metal influence on the iso- and hetero-selectivity of complexes of bipyrrolidine derived salan ligands for the polymerisation of rac-lactide.
In this paper we have prepared a series of Ti(iv), Hf(iv) and Al(iii) complexes based on bipyrrolidine salan pro-ligands. The Hf(iv) complexes have all been characterised in the solid-state, the chiral ligands coordinate to Hf(iv) in an α-cis manner whereas the meso ligand coordinates in a β-cis geometry. The Hf(iv) complexes are all active for the ROP of rac-lactide in the melt, with the fluxi...
متن کاملMetal influence on the iso- and hetero-selectivity of complexes of bipyrrolidine derived salan ligands for the polymerisation of rac-lactide† †Electronic supplementary information (ESI) available: Full experimental data and crystal data in the .cif format. CCDC 1401694–1401702. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c5sc01819f Click here for additional data file. Click here for additional data file. Click here for additional data file.
In this paper we have prepared a series of Ti(IV), Hf(IV) and Al(III) complexes based on bipyrrolidine salan proligands. The Hf(IV) complexes have all been characterised in the solid-state, the chiral ligands coordinate to Hf(IV) in an a-cismanner whereas themeso ligand coordinates in a b-cis geometry. The Hf(IV) complexes are all active for the ROP of rac-lactide in the melt, with the fluxiona...
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The first synthesis of Salan ligands assembled around the chiral 2,2'-bipyrrolidine backbone is described; as chelation to a metal can only occur via specific faces of the two pyrrolidine nitrogens, these ligands lead to predetermined chirality at metal centres of octahedral titanium and zirconium complexes.
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Phenylenediamine bis(phenolate) binds in the reduced dianionic form to titanium and zirconium alkoxides giving either mononuclear or bridging dinuclear complexes depending on the metal precursors; the fluxional mononuclear titanium complex is found to exhibit extremely high activity in polymerisation of rac-lactide in the melt.
متن کاملNovel Ti(IV) and Zr(IV) complexes and their application in the ring-opening polymerisation of cyclic esters.
A series of group 4 amine tris(phenolate) complexes have been prepared and characterised by single crystal X-ray diffraction and multinuclear NMR spectroscopy. It was found that the ligands afforded monomeric titanium complexes and dimeric zirconium structures in the solid-state. The complexes have been tested for the ring-opening polymerisation of rac-lactide under both solution and melt condi...
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عنوان ژورنال:
- Chemical communications
دوره 50 100 شماره
صفحات -
تاریخ انتشار 2014