End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerizatio...End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.展开更多
A series of new lanthanide-radical complexes [{Ln（hfac）3}2（NITPhlM）2] （Ln = Nd （1）, Eu （2）, Tb （3）, Er （4）; hfac = hexafluoroacetylacetonate; NITPhlM = 2-[4-（1-imidazole）phenyl]-4,4,5,5-tetramethylimida...A series of new lanthanide-radical complexes [{Ln（hfac）3}2（NITPhlM）2] （Ln = Nd （1）, Eu （2）, Tb （3）, Er （4）; hfac = hexafluoroacetylacetonate; NITPhlM = 2-[4-（1-imidazole）phenyl]-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide） have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln（hfac）3 units bridged by the paramagnetic ligands by the means of coor- dination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl ni- troxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior.展开更多
基金Supported by PetroChina Company Limited(2020 B-2711)。
文摘End-functionalization of polydiene rubbers can not only improve its compatibility with inorganic fillers,but also enhance the overall mechanical properties.Nevertheless,for traditional neodymium(Nd)diene polymerization systems,it is highly challenging to achieve such end-functionalizations,because most of polydienyl chains are capped withη3-allyl-Nd moiety during the end of polymerization,which shows very poor reactivity with nucleophile compounds.We launched a new diene polymerization strategy calling coordinative chain transfer polymerization(CCTP)[1].In such a system,all the polydienyl chains are capped withη1-allyl-Al moieties,which reveal greater reactivity with cyclic esters and epoxide compounds,providing an effective manner to prepare polydiene-polyester amphiphilic block copolymers.Inspired by such findings,we now show herein how such types of chain-ends react with isot-hiocyanate to demonstrate an efficient in-situ manner to access end-functionalized polydienes by using CCTP.
基金financially supported by the National Natural Science Foundation of China (20971072, 91122013, 90922032)the Fundamental Research Funds for the Central Universities
文摘A series of new lanthanide-radical complexes [{Ln（hfac）3}2（NITPhlM）2] （Ln = Nd （1）, Eu （2）, Tb （3）, Er （4）; hfac = hexafluoroacetylacetonate; NITPhlM = 2-[4-（1-imidazole）phenyl]-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide） have been prepared and characterized. Single crystal X-ray diffraction analyses reveal that these complexes are isostructural with one-dimensional chain structures. These consist in Ln（hfac）3 units bridged by the paramagnetic ligands by the means of coor- dination of their nitronyl nitroxide groups and imidazole rings. Interestingly, each Ln ion is either bound to two nitronyl ni- troxide groups or to two imidazole units, and the different Ln centers alternate along the chain. Magnetic studies show that complex 3 exhibits a single-chain magnet behavior.
