Molecular self-assembly is crucially fundamental to nature.However,the aqueous self-assembly of polymers is still a challenge.To achieve self-assembly of block copolymers [(polyacrylic acid-block-polyethylene glycol-b...Molecular self-assembly is crucially fundamental to nature.However,the aqueous self-assembly of polymers is still a challenge.To achieve self-assembly of block copolymers [(polyacrylic acid-block-polyethylene glycol-block-polyacrylic acid(PAA68-b-PEG86-b-PAA68)] in an aqueous phase,manganese oxide(MnO2) is first generated to drive phase separation of the PAA block to form the PAA68-b-PEG68-b-PAA68/MnO2 polymeric assembly that exhibits a stable structure in a physiological medium.The polymeric assembly exhibits vesicular morphology with a diameter of approximately 30 nm and high doxorubicin(DOX) loading capacity of approximately 94%.The transformation from MnO2 to Mn2+caused by endogenous glutathione(GSH)facilitates the disassembly of PAA68-b-PEG68-b-PAA68/MnO2 to enable its drug delivery at the tumor sites.The toxicity of DOXloaded PAA68-b-PEG68-b-PAA69/MnO2 to tumor cells has been verified in vitro and in vivo.Notably,drug-loaded polymeric vesicles have been demonstrated,especially in in vivo studies,to overcome the cardiotoxicity of DOX.We expect this work to encourage the potential application of polymer self-assembly.展开更多
Bismuth-based compounds with high capacity and durability are still challenging in Li-ion batteries(LIBs).In this article,Bi_(2)S_(3)nanorods hosted on reduced graphene oxide nanosheets(Bi_(2)S_(3)/rGO,BSG)are success...Bismuth-based compounds with high capacity and durability are still challenging in Li-ion batteries(LIBs).In this article,Bi_(2)S_(3)nanorods hosted on reduced graphene oxide nanosheets(Bi_(2)S_(3)/rGO,BSG)are successfully prepared using molecular precursor pyrolysis strategy.1D nanorod architecture possesses preeminent kinetic characteristics,shortening the ion diffusion path and increasing the contact area between electrode and electrolyte.The large specific surface area and charge polarization of rGO at the interface promote charge transfer.The capacity of material(BSG-400)reaches 558.4 m Ah g^(-1)at 0.2 A g^(-1)after 200 cycles.The anode properties of the composite outperform those of pristine Bi_(2)S_(3).The introduction of graphene enables the interfacial interaction between rGO and Bi_(2)S_(3).The closely contact interface improves the conductivity and lithium storage performances of Bi_(2)S_(3).The regulatory effect of rGO on the electronic density of states and band gap of Bi_(2)S_(3)has been demonstrated by theoretical calculation.The synthetic approach has the advantages of universality,simple operation procedure,and strong repeatability.This research provides some ideas for the preparation of other metal sulfides/rGO nanomaterials and their application in battery research.展开更多
Comprehensive Summary,We herein report a simple ether-directed iridium-catalyzed site-and enantioselective C(sp^(2))-H borylation of benzhydryl ethers for the first time.Various chiral benzhydryl ethers were obtained ...Comprehensive Summary,We herein report a simple ether-directed iridium-catalyzed site-and enantioselective C(sp^(2))-H borylation of benzhydryl ethers for the first time.Various chiral benzhydryl ethers were obtained with high enantioselectivities in the presence of a tailor-made chiral bidentate boryl ligand.We found that the kinetic resolution relay significantly amplified the enantioselectivity.The synthetic utility of the current method was demonstrated by gram-scale C—H borylation and C—B bond transformations.展开更多
The sustainable development of synthetic reactions catalyzed by earth-abundant metals is one of the principal goals in homogeneous catalysis.However,so far most of the protocols are still plagued by sophisticated liga...The sustainable development of synthetic reactions catalyzed by earth-abundant metals is one of the principal goals in homogeneous catalysis.However,so far most of the protocols are still plagued by sophisticated ligands,hazardous activators,high catalyst loading(1—10 mol%)and/or multistep synthesis of the metal complexes in the process development.Consequently,the development of earth-abundant metal catalysts with high activity from commercially available metal salts is highly desirable for practical utilization of base metal catalyzed synthetic methodology.Herein,we report the catalyst generated in situ from a mixture of catalytic amounts of Ni(acac)_(2)(as low as 0.005 mol%)and CsF,which is found highly active for Markovnikov-selective hydroboration of vinylarenes,including 1,1-disubstituted vinylarenes and internal olefins,affording a wide range of secondary and tertiary alkyl boronates in excellent yields.Mechanistic experiments indicate that the key to the success of this catalysis is the use of CsF,which in combination with pinacolborane acts as an effective activator for Ni(acac)_(2),probably generating metastable Ni nanoparticles in situ that demonstrate high activity in the catalytic hydroboration(TON up to 18800).展开更多
基金financial support from the National Natural Science Foundation of China(21704093)Project funded by China Postdoctoral Science Foundation(2018M632795)+1 种基金Supports Plan for College Science and Technology Innovation Team of Henan Province(16IRTSTHN001)Science&Technology Innovation Talent Plan of Henan Province(174200510018)。
文摘Molecular self-assembly is crucially fundamental to nature.However,the aqueous self-assembly of polymers is still a challenge.To achieve self-assembly of block copolymers [(polyacrylic acid-block-polyethylene glycol-block-polyacrylic acid(PAA68-b-PEG86-b-PAA68)] in an aqueous phase,manganese oxide(MnO2) is first generated to drive phase separation of the PAA block to form the PAA68-b-PEG68-b-PAA68/MnO2 polymeric assembly that exhibits a stable structure in a physiological medium.The polymeric assembly exhibits vesicular morphology with a diameter of approximately 30 nm and high doxorubicin(DOX) loading capacity of approximately 94%.The transformation from MnO2 to Mn2+caused by endogenous glutathione(GSH)facilitates the disassembly of PAA68-b-PEG68-b-PAA68/MnO2 to enable its drug delivery at the tumor sites.The toxicity of DOXloaded PAA68-b-PEG68-b-PAA69/MnO2 to tumor cells has been verified in vitro and in vivo.Notably,drug-loaded polymeric vesicles have been demonstrated,especially in in vivo studies,to overcome the cardiotoxicity of DOX.We expect this work to encourage the potential application of polymer self-assembly.
基金Financial supports from the National Natural Science Foundation of China(no.21401168)Dalian Institute of Chemical Physics(no.N-19-11)
文摘Bismuth-based compounds with high capacity and durability are still challenging in Li-ion batteries(LIBs).In this article,Bi_(2)S_(3)nanorods hosted on reduced graphene oxide nanosheets(Bi_(2)S_(3)/rGO,BSG)are successfully prepared using molecular precursor pyrolysis strategy.1D nanorod architecture possesses preeminent kinetic characteristics,shortening the ion diffusion path and increasing the contact area between electrode and electrolyte.The large specific surface area and charge polarization of rGO at the interface promote charge transfer.The capacity of material(BSG-400)reaches 558.4 m Ah g^(-1)at 0.2 A g^(-1)after 200 cycles.The anode properties of the composite outperform those of pristine Bi_(2)S_(3).The introduction of graphene enables the interfacial interaction between rGO and Bi_(2)S_(3).The closely contact interface improves the conductivity and lithium storage performances of Bi_(2)S_(3).The regulatory effect of rGO on the electronic density of states and band gap of Bi_(2)S_(3)has been demonstrated by theoretical calculation.The synthetic approach has the advantages of universality,simple operation procedure,and strong repeatability.This research provides some ideas for the preparation of other metal sulfides/rGO nanomaterials and their application in battery research.
基金the National Natural Science Foundation of China(92256302 and 91956116)the Natural Science Foundation of Jiangsu Province(BK20211092)+1 种基金the Major Program of the Lanzhou Institute of Chemical Physics,CAS(No.ZYFZFX-9)Lanzhou Institute of Chemical Physics for generous financial support.
文摘Comprehensive Summary,We herein report a simple ether-directed iridium-catalyzed site-and enantioselective C(sp^(2))-H borylation of benzhydryl ethers for the first time.Various chiral benzhydryl ethers were obtained with high enantioselectivities in the presence of a tailor-made chiral bidentate boryl ligand.We found that the kinetic resolution relay significantly amplified the enantioselectivity.The synthetic utility of the current method was demonstrated by gram-scale C—H borylation and C—B bond transformations.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(No.21821002).
文摘The sustainable development of synthetic reactions catalyzed by earth-abundant metals is one of the principal goals in homogeneous catalysis.However,so far most of the protocols are still plagued by sophisticated ligands,hazardous activators,high catalyst loading(1—10 mol%)and/or multistep synthesis of the metal complexes in the process development.Consequently,the development of earth-abundant metal catalysts with high activity from commercially available metal salts is highly desirable for practical utilization of base metal catalyzed synthetic methodology.Herein,we report the catalyst generated in situ from a mixture of catalytic amounts of Ni(acac)_(2)(as low as 0.005 mol%)and CsF,which is found highly active for Markovnikov-selective hydroboration of vinylarenes,including 1,1-disubstituted vinylarenes and internal olefins,affording a wide range of secondary and tertiary alkyl boronates in excellent yields.Mechanistic experiments indicate that the key to the success of this catalysis is the use of CsF,which in combination with pinacolborane acts as an effective activator for Ni(acac)_(2),probably generating metastable Ni nanoparticles in situ that demonstrate high activity in the catalytic hydroboration(TON up to 18800).
