Aluminium salophen and salen initiators in the ring-opening polymerisation of rac-lactide and rac-β-butyrolactone: Electronic effects on stereoselectivity and polymerisation rates
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چکیده
منابع مشابه
Salalen aluminium complexes and their exploitation for the ring opening polymerisation of rac-lactide.
In this paper we report the first use of Al(III) salalen complexes for the ring opening polymerisation of rac-lactide. Polylactides with narrow polydispersities (PDIs range from 1.04-1.65) and moderate degrees of stereoselectivity were formed. Eight salalen Al(III) complexes have been prepared and fully characterised by solution-state NMR spectroscopy and, where appropriate, single crystal X-ra...
متن کاملRobust chiral zirconium alkoxide initiators for the room-temperature stereoselective ring-opening polymerisation of rac-lactide.
Chiral Schiff bases (1H to 4H) and a series of their Group 4 metal alkoxide complexes [(R-1)2Ti(O(i)Pr)2, (R-2)2Ti(O(i)Pr)2, (R-1)(2)Zr(O(i)Pr)2, (R-2)2Zr(O(i)Pr)2, (R-3)2Zr(O(i)Pr)2, (R-4)2Zr(O(i)Pr)2, (S-1)2Zr(O(i)Pr)2 and (rac-1)2Zr(O(i)Pr)2] have been prepared and characterised by 1H, and 13C NMR spectroscopy. In solution, both Lambda and Delta isomers were observed, suggesting a low degree...
متن کاملHeterogeneous catalysts for the controlled ring-opening polymerisation of rac-lactide and homogeneous silsesquioxane model complexes.
In this communication we report, for the first time, the ring-opening polymerisation in the melt of rac-lactide with heterogeneous catalysts. Homogeneous model systems based on silsesquioxanes have been prepared for comparison.
متن کاملMonomeric Ti(IV) homopiperazine complexes and their exploitation for the ring opening polymerisation of rac-lactide
BACKGROUND The area of biodegradable/sustainable polymers is one of increasing importance in the 21st Century due to their positive environmental characteristics. Lewis acidic metal centres are currently one of the most popular choices for the initiator for the polymerisation. Thus, in this paper we report the synthesis and characterisation of a series of monometallic homopiperazine Ti(IV) comp...
متن کاملSynthesis and rac-lactide ring-opening polymerisation studies of new alkaline earth tetrahydroborate complexes.
Reaction of K[HC(C(Me)NAr')(2)] (Ar' = 2,6-C(6)H(3)(i)Pr(2)) with Mg(BH(4))(2) afforded the pseudo four-coordinate tetrahydroborate complex Mg{HC(C(Me)NAr')(2)}(BH(4))(THF) (1). The corresponding reaction of Ca(BH(4))(2)(THF)(2) or Sr(BH(4))(2)(THF)(2) gave the pseudo five-coordinate analogues M{HC(C(Me)NAr')(2)}(BH(4))(THF)(2) (M = Ca (2) or Sr (3)). All three compounds 1-3 have been structura...
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ژورنال
عنوان ژورنال: Journal of Organometallic Chemistry
سال: 2013
ISSN: 0022-328X
DOI: 10.1016/j.jorganchem.2013.08.023