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Na Liu - One of the best experts on this subject based on the ideXlab platform.
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Self-assembly and fluorescence emission of UV-responsive azobenzene-containing helical poly(Phenyl Isocyanide) copolymers
Polymer Chemistry, 2020Co-Authors: Hui Zou, Li Zhou, Yong-yuan Chen, Xiao-hua Hou, Na LiuAbstract:Azobenzene (Azo)-containing Phenyl Isocyanide (AzoPI, monomer 1) was synthesized via the combination of Williamson etherification and a transesterification reaction, and it could be polymerized to afford poly-1n with the Phenyl alkyne–Pd(II) complex as the initiator in a living/controlled manner. Since the obtained poly-1n was living, helical copolymers were obtained through the polymerization of oligo polyethylene glycol group-functionalized Phenyl Isocyanide (monomer 2) using poly-140 as the macroinitiator. The obtained copolymers were optically active and exhibited light-responsive properties. The poly(140-b-2m) copolymers were amphiphilic and could self-assemble into supramolecular aggregates in aqueous solutions. The TEM results showed that poly(140-b-220) self-assembled to form hollow spindly aggregates with an average length of ∼430 nm and an average diameter of ∼160 nm, while poly(140-b-240) self-assembled into wormlike micelles with an average length of ∼280 nm and an average width of ∼48 nm, and poly(140-b-280) self-assembled into spherical micelles with an average diameter of ∼82 nm. Meanwhile, when α-cyclodextrin (α-CD) was added into the aqueous solution of poly(140-b-240), the wormlike micelles of poly(140-b-240) changed into spherical micelles of the poly(140-b-240)/α-CD complex with an average diameter of ∼104 nm. What's more, due to the UV-response of Azo groups, irregular aggregates of poly(140-b-240) and poly(140-b-240)/α-CD were observed upon UV irradiation. In the meantime, the fluorescence emission of Azo groups was unexpectedly observed in THF solution. When water was added into the THF solution, the intensity of the fluorescence emission became higher. Moreover, the fluorescence intensity increased with the increase in the ratio of water to THF.
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polymerization amplified stereoselectivity pass of asymmetric michael addition reaction and aldol reaction catalyzed by helical poly Phenyl Isocyanide bearing secondary amine pendants
Macromolecules, 2018Co-Authors: Ling Shen, Xiao-hua Hou, Na LiuAbstract:A novel enantiopure Phenyl Isocyanide (1) carrying tert-butyloxycarboryl (Boc) protected l-prolinol ester was designed and synthesized. Living polymerization of 1 using a alkyne–Pd(II) catalyst afforded helical poly-1ms in high yields with controlled molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns). Removing the protecting Boc groups on the l-prolinol ester pendants lead to the formation of helical poly-2m, which showed high optical activity owing to the preferred left-handed helix of polyIsocyanide main chain. The poly-2ms showed excellent catalytic ability on asymmetric Michael addition reaction. Both the enantiomeric excess (ee) and diastereomeric ratio (dr) values of the product were linearly correlated to the Mn and optical activity of poly-2m. Increasing the Mn of poly-2ms will amplify the stereoselectivity of the asymmetric Michael addition reaction until the Mn reached to 44.9 kDa, revealing the polymerization amplified stereoselectivity (PASS) behavior of the asymmetric ...
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a facile synthetic route to multifunctional poly 3 hexylthiophene b poly Phenyl Isocyanide copolymers from aggregation induced emission to controlled helicity
Macromolecules, 2018Co-Authors: Na Liu, Hui ZouAbstract:New synthetic methods are of great significance in enabling access to valuable compounds and materials. Although conjugated poly(3-hexylthiophene) (P3HT) has been widely investigated, P3HT copolymers containing functional groups (such as amino, imino, hydroxyl, etc.) are rarely reported because of inherent synthetic difficulties. Here P3HT copolymers bearing diverse functional pendants, which cannot be obtained by the direct block copolymerization of the corresponding monomers, were designed and facilely synthesized through the postpolymerization modification method. First, P3HT-b-poly(Phenyl Isocyanide) (P3HT-b-PPI) with pentafluoroPhenyl (PFP) ester was prepared in one-pot using Ni(dppp)Cl2 as the catalyst. Then, through the postpolymerization modification of the copolymer with alcohols and amines, P3HT-b-PPIs copolymers bearing defined functional groups were facilely obtained. The introduction of functional pendants endowed P3HT-b-PPIs copolymers with diverse functionalities. When pyrene pendants were ...
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Enantiomer-selective Living Polymerization of rac -Phenyl Isocyanide Using Chiral Palladium Catalyst
Chinese Journal of Polymer Science, 2018Co-Authors: Jian Huang, Hui Zou, Ling Shen, Na LiuAbstract:We report the polymerization of Phenyl Isocyanides with the chiral palladium(II) initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic Isocyanide monomer (rac-1), and enantiomerically unbalanced polymerization of the monomer was found, providing substantial evidence for the enantiomer-selective polymerization of rac-1 mediated through chiral catalyst. A comparison between the enantiomerically pure monomers, 4-isocyanobenzoyl-L-alanine decyl ester (1s) and 4-isocyanobenzoyl-D-alanine decyl ester (1r), revealed a drastic discrepancy in the reactivity ratio of their homopolymerizations. It turned out that the monomer reactivity ratio of 1s was higher than that of 1r with chiral ligands. The results clearly demonstrated the inclination for incorporation of the 1s enantiomer during the polymerization process and thus resulted in the enantiomer-selective polymerization in this system. The effects of the catalyst chirality on the optically active properties of polymerization were investigated, and it was concluded that the formation of higher-ordered conformation with a handed helicity might be attributed to the chiral induction of chiral palladium(II) catalyst. Moreover, the polymers obtained through the enantiomer-selective polymerization of the enantiomerically pure monomer were with a significant improvement of the optical activity if the chirality of the monomer and the catalyst matched with each other.
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Combination of RAFT and Pd(II)-Initiated Isocyanide Polymerizations: A Versatile Method for Facile Synthesis of Helical Poly(Phenyl Isocyanide) Block and Star Copolymers
Macromolecules, 2018Co-Authors: Zhi-qiang Jiang, Song-qing Zhao, Na LiuAbstract:We report a new method for facile synthesis of block and star copolymers composed of helical poly(Phenyl Isocyanide) and polyacrylate segments via combination of Pd(II)-initiated Isocyanide polymerization and reversible addition–fragmentation chain transfer (RAFT) controlled radical polymerization. First, an alkyne–Pd(II) complex containing benzyl trithiocarbonate substituent was designed and synthesized. The Pd(II) moiety of the complex can catalyzed the living polymerization of Phenyl Isocyanides, while the benzyl trithiocarbonate unit can be used as a chain transfer agent for RAFT polymerization. Upon combination of the two living polymerizations, a series of block copolymers containing poly(Phenyl Isocyanide) and polyacrylate, poly(aryl vinyl) blocks with expected molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns) can be facilely prepared under controlled manner. Some of these block copolymers exhibited interesting self-assembly and stimuli-responsive properties. Taking advanta...
Jun Yin - One of the best experts on this subject based on the ideXlab platform.
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Synthesis of Unimolecular Micelles with Incorporated Hyperbranched Boltorn H30 Polyester modified with Hyperbranched Helical Poly(Phenyl Isocyanide) Chains and their Enantioselective Crystallization Performance.
Macromolecular rapid communications, 2017Co-Authors: Zhi-huang Zhang, Chen-yang Qiao, Jian Zhang, Wen-ming Zhang, Jun YinAbstract:Here, the fabrication of unimolecular micelles functionalized with helical polymeric chains as a chiral nucleating agent in enantioselective crystallization is reported. Starting from a fractionated hyperbranched polyester (Boltorn H30), the ring-opening polymerization of l-lactic acid (LLA) and subsequent terminal-group modification affords the alkyne-Pd(II)-anchored hyperbranched macroinitiator (H30-PLLA-Pd). By taking advantage of a Pd(II)-catalyzed living polymerization of chiral pendant modified l- or d-Phenyl Isocyanide (PI) monomers, well-defined chiral unimolecular micelles (H30-PLLA-PPI) grafted with radiating helical PPI coronas of one predominant screw sense are obtained. The resultant chiral materials demonstrate excellent application in the enantioselective crystallization of racemic threonine in water, and a 92% enantiomeric excess value of the residual solution is obtained. It is believed this present proof of concept and methodology are facile and powerful for preparing novel and versatile chiral materials with different topological structures, not only applicable to PPI but also to other types of polymers.
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High-Efficiency Cell-Penetrating Helical Poly(Phenyl Isocyanide) Chains Modified Cellular Tracer and Nanovectors with Thiol Ratiometric Fluorescence Imaging Performance
Macromolecules, 2017Co-Authors: Xin Han, Jian Zhang, Chen-yang Qiao, Wen-ming Zhang, Jun YinAbstract:In order to precisely tail the endocytosis process and determine the internal location of drug carriers in cells, fluorescent tracers with high sensitivity and versatility are one of the most powerful tools. Nevertheless, conventional single fluorescent probes always suffered from the interference of background fluorescence or the lack of long-time monitoring capability, resulting in the low resolution and efficiency. To overcome this drawback, nanocarriers capable of multicolor fluorogenic and ratiometric properties became an urgently needed solution. In this contribution, starting from pentafluoroPhenyl ester (PFP)- and tetraPhenylethene (TPE)-functionalized Phenyl Isocyanide (PI) monomers as well as l-hydrophilic (HP) PI monomers, a type of well-defined amphiphilic block copolymer, P(PFPPI-co-TPEPI-co-HPPI)-b-HPPPI, with controlled molecular weights and tunable compositions was prepared through sequential living copolymerization with Phenylethynyl Pd(II) complex as a single catalyst in one pot. Disulfi...
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Grafting polymerization of single-handed helical poly(Phenyl Isocyanide)s on graphene oxide and their application in enantioselective separation
Journal of Polymer Science Part A: Polymer Chemistry, 2017Co-Authors: Yi Xiao, Zhi-qiang Jiang, Jun Yin, Hui-qing Wang, Hao Zhang, Ya-qi Wang, Yuan-yuan ZhuAbstract:We herein report a “grafting from” strategy to immobilize optically active helical poly(Phenyl Isocyanide)s onto graphene oxide (GO) nanosheets. After covalently bounding alkyne-Pd(II) initiator onto GO nanosheets, the designed GO/polymer composites P1@GO and P1-b-P2@GO featuring single-handed helical poly(Phenyl Isocyanide)s growing from GO nanosheets were prepared by sequential addition of the chiral and achiral Isocyanide monomers. Post-synthetic hydrolysis rendered P1-b-P3@GO to improve the hydrophilicity. The successful covalent bonding of poly(Phenyl Isocyanide)s chains onto GO nanosheets was certified by several cross evidences including scan emission microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Circular dichroism spectra proved that the chiral information was introduced through the grafted single-handed helical polymer chains successfully. In addition, the resulting GO/polymer composites were explored as a chiral additive to induce enantioselective crystallization of racemic organic molecules. Preferential formation of rod-like L-alanine crystals was induced by composites bearing right-handed helical poly(Phenyl Isocyanide)s. The enantiomeric excess value of the induced crystals reached 76%, displaying the potential in future applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2092–2103
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High-Efficiency Cell-Penetrating Helical Poly(Phenyl Isocyanide) Chains Modified Cellular Tracer and Nanovectors with Thiol Ratiometric Fluorescence Imaging Performance
2017Co-Authors: Xin Han, Jian Zhang, Chen-yang Qiao, Wen-ming Zhang, Jun YinAbstract:In order to precisely tail the endocytosis process and determine the internal location of drug carriers in cells, fluorescent tracers with high sensitivity and versatility are one of the most powerful tools. Nevertheless, conventional single fluorescent probes always suffered from the interference of background fluorescence or the lack of long-time monitoring capability, resulting in the low resolution and efficiency. To overcome this drawback, nanocarriers capable of multicolor fluorogenic and ratiometric properties became an urgently needed solution. In this contribution, starting from pentafluoroPhenyl ester (PFP)- and tetraPhenylethene (TPE)-functionalized Phenyl Isocyanide (PI) monomers as well as l-hydrophilic (HP) PI monomers, a type of well-defined amphiphilic block copolymer, P(PFPPI-co-TPEPI-co-HPPI)-b-HPPPI, with controlled molecular weights and tunable compositions was prepared through sequential living copolymerization with Phenylethynyl Pd(II) complex as a single catalyst in one pot. Disulfide bonds were then introduced by the exchange reaction between PFP units and cystamine (Cys; a degradable cross-linker). The resultant P(CysPI-co-TPEPI-co-HPPI)-b-HPPPI copolymers showed a time-dependent disruption in the conditions mimicking the intracellular reducing environment and an aggregation-caused quenching (ACQ) optical behavior that they were emissive when single chain dispersed but became nonfluorescent if the polymer chains were aggregated. Thanks to such a unique optical phenomenon, nanocarriers capable of fluorescence ratiometric property could be constructed after incorporating another solvatochromic dye, Nile red (NR), in water. This new class of core cross-linked NR@P(CysPI-co-TPEPI-co-HPPI)-b-HPPPI micelles not only exhibited excellent fluorescence ratiometric cell imaging ability but also possessed rapid cell membrane permeability due to the PEGylated single left-handed helical PPI corona and exposed the real-time disintegration of nanocarriers in front of us. Fatal and irreversible damage to cancer cells could be achieved by the high-efficiency delivery of chemotherapeutic agents. We speculate that these newly developed fluorescent integrated nanocarriers can potentially be utilized as a promising approach to cancer diagnosis and therapy
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A facile synthetic route to stereoregular helical poly(Phenyl Isocyanide)s with defined pendants and controlled helicity
Polymer Chemistry, 2017Co-Authors: Jun Yin, Xin Han, Li ZhouAbstract:The living polymerization of a pentafluoroPhenyl (PFP) ester-functionalized Phenyl Isocyanide (1) using an alkyne–Pd(II) initiator affords well-defined poly(Phenyl Isocyanide)s with controlled molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns). Post-polymerization modification of these polymers using alcohols and amines formed poly(Phenyl Isocyanide)s with defined ester and amide pendants. However, the polymers are optically inactive even when chiral alcohols and amines were used in the post-modification reactions. Interestingly, living polymerization of 1 using the Pd(II) initiator can be carried out in the presence of alcohols and amines in one-pot. Such one-pot polymerizations lead to the formation of well-defined helical poly(Phenyl Isocyanide)s in high yields with defined pendants through the linkage of an ester or amide. Remarkably, optically active helical poly(Phenyl Isocyanide)s with preferred handedness were facilely obtained when chiral alcohols and amines were used in one-pot polymerizations. The optical activities of the afforded helical polyIsocyanides were relatively high and comparable to those prepared via polymerization of the corresponding enantiopure Phenyl Isocyanide monomers bearing chiral ester or amide groups.
Yuan-yuan Zhu - One of the best experts on this subject based on the ideXlab platform.
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Optically Active Helical PolyIsocyanides Bearing Chiral Phosphine Pendants: Facile Synthesis and Application in Enantioselective Rauhut-Currier Reaction
Chinese Journal of Polymer Science, 2017Co-Authors: Li Zhou, Na Liu, Jian Huang, Ling Shen, Yuan-yuan ZhuAbstract:Three novel enantiopure Phenyl Isocyanide monomers with BH3-protected phosphine functional group were designed and synthesized. Polymerization of these monomers using a alkyne-Pd(II) complex as a catalyst led to the formation of respective helical polyIsocyanides in high yields with controlled molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns). Removing the protecting BH3 groups afforded helical poly(Phenyl Isocyanide)s bearing phosphine pendants. Thanks to the chiral induction of monomer, the isolated helical polyIsocyanides showed high optical activity, as revealed by circular dichroism (CD) and absorption spectroscopies and polarimetry. The helical structures of these polymers were quite stable in various organic solvents with different polarities and in a wide temperature range. Moreover, these helical polymers could be used as organocatalysts and showed good performance in enantioselective cross Rauhut-Currier reaction. The enantiomeric excess (ee) values of the isolated products of cross Rauhut-Currier reaction could be up to 90%. The polymer organocatalysts could be easily recovered from the reaction mixtures and reused at least five times in the reaction without significant loss of their enantioselectivities and catalytic activities.
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Grafting polymerization of single-handed helical poly(Phenyl Isocyanide)s on graphene oxide and their application in enantioselective separation
Journal of Polymer Science Part A: Polymer Chemistry, 2017Co-Authors: Yi Xiao, Zhi-qiang Jiang, Jun Yin, Hui-qing Wang, Hao Zhang, Ya-qi Wang, Yuan-yuan ZhuAbstract:We herein report a “grafting from” strategy to immobilize optically active helical poly(Phenyl Isocyanide)s onto graphene oxide (GO) nanosheets. After covalently bounding alkyne-Pd(II) initiator onto GO nanosheets, the designed GO/polymer composites P1@GO and P1-b-P2@GO featuring single-handed helical poly(Phenyl Isocyanide)s growing from GO nanosheets were prepared by sequential addition of the chiral and achiral Isocyanide monomers. Post-synthetic hydrolysis rendered P1-b-P3@GO to improve the hydrophilicity. The successful covalent bonding of poly(Phenyl Isocyanide)s chains onto GO nanosheets was certified by several cross evidences including scan emission microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Circular dichroism spectra proved that the chiral information was introduced through the grafted single-handed helical polymer chains successfully. In addition, the resulting GO/polymer composites were explored as a chiral additive to induce enantioselective crystallization of racemic organic molecules. Preferential formation of rod-like L-alanine crystals was induced by composites bearing right-handed helical poly(Phenyl Isocyanide)s. The enantiomeric excess value of the induced crystals reached 76%, displaying the potential in future applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2092–2103
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Solvent-Induced White-Light Emission of Amphiphilic Rod–Rod Poly(3-triethylene glycol thiophene)-block-poly(Phenyl Isocyanide) Copolymer
2016Co-Authors: Na Liu, Jun Yin, Ying Wang, Dengfeng Liu, Yuan-yuan ZhuAbstract:A class of amphiphilic rod–rod diblock copolymers composed of hydrophilic π-conjugated poly(3-triethylene glycol thiophene) (P3(TEG)T) and hydrophobic rigid-rod-like poly(Phenyl Isocyanide) (PPI) was synthesized in one pot via mechanistically distinct, sequential block copolymerization with Ni(dppp)Cl2 as a single catalyst. The hydrophilic P3(TEG)T homopolymer self-assembled into well-defined nanoparticles in THF and methanol with different dimensions and exhibited orange-light emission in THF and red-light emission in methanol. Interestingly, the resultant P3(TEG)T-b-PPI block copolymers were found to self-assembled into various well-defined supramolecular structures, such as nanofibrils in THF, micelles in methanol, and vesicles in 3/2 mixtures of THF and methanol. The assemblies of these block copolymers in solutions exhibited unique light emissions with the emission color spanned widely from orange red to blue depending on self-assembled morphology and solvents used. White light emission can be readily achieved through the control of self-assembled morphologies by variation on the solvent composition. Moreover, the light emissions of the block copolymers were completely reversible, demonstrating the tunable emissions were indeed ascribed to the morphological transitions of the block copolymer
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polypeptide b poly Phenyl Isocyanide hybrid rod rod copolymers one pot synthesis self assembly and cell imaging
Macromolecular Rapid Communications, 2015Co-Authors: Sheng-yu Shi, Na Liu, Yuan-yuan Zhu, Yunsheng Ding, Weiwei Chen, Jun YinAbstract:Hybrid rod-rod diblock copolymers, poly(γ-benzyl L-glutamate)-poly(4-cyano-benzoic acid 2-isopropyl-5-methyl-cyclohexyl ester) (PBLG-PPI), with determined chirality are facilely synthesized through sequential copolymerization of γ-benzyl-L-glutamate N-carboxyanhydride (BLG-NCA) and Phenyl Isocyanide monomers bearing chiral menthyl pendants using a Ni(cod)(bpy) complex as the catalyst in one-pot. Circular dichroism and absorption spectra reveal that each block of the block copolymers possesses a stable helical conformation with controlled helicity in solution due to the induction of chiral pendants. The two diastereomeric polymers self-assemble into helical nanofibrils with opposite handedness due to the different chiral induction of the L- and D-menthyl pendants, confirmed by transmission electron microscopy (TEM). Deprotection of the benzyl groups of the PBLG segment affords biocompatible amphiphilic diblock copolymers, poly(L-glutamic acid)-poly(4-cyano-benzoic acid 2-isopropyl-5-methyl-cyclohexyl ester) (PLGA-PPI), that can self-assemble into well-defined micelles by cosolvent induced aggregation. Very interestingly, a chiral rhodamine chromophores RhB(D) can be selectively encapsulated into the chiral polymeric micelles, which is efficiently internalized into living cells when directly monitored with a confocal microscope. This contribution will be useful for developing novel rod-rod biocompatible hybrid block copolymers with a controlled helicity, and may also provide unique chiral materials for potential bio-medical applications.
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Facile synthesis of stereoregular helical poly(Phenyl Isocyanide)s and poly(Phenyl Isocyanide)-block-poly(L-lactic acid) copolymers using alkylethynylpalladium(II) complexes as initiators
Polymer Chemistry, 2015Co-Authors: Jia-li Chen, Zhi-qiang Jiang, Na Liu, Jun Yin, Yuan-yuan ZhuAbstract:The development of novel synthetic methods for the facile preparation of well-defined stereoregular helical polyIsocyanides and their block copolymers in a living/controlled fashion is of great interest. In this contribution, a family of air-stable alkylethynyl Pd(II) complexes was unexpectedly found to promote the living polymerization of Phenyl Isocyanide, affording poly(Phenyl Isocyanide)s with controlled molecular weights, narrow molecular weight distributions and high stereoregularity. Interestingly, such alkylethynyl Pd(II) complexes exhibit very high helix-sense-selectivity in the living polymerization of an optically active Phenyl Isocyanide bearing an L-alanine pendant with a long decyl chain, and a single handed helical poly(Phenyl Isocyanide) with controlled helical sense was selectively produced. Moreover, a Pd(II) complex bearing a hydroxyl group can initiate the living polymerization of both Phenyl Isocyanide and L-lactide in one-pot, leading to the formation of well-defined poly(Phenyl Isocyanide)-b-poly(L-lactic acid) copolymers in high yields with controlled molecular weights and tunable compositions. Although the two monomers were polymerized via distinct mechanisms, the block copolymerization was revealed to proceed under living/controlled manners.
Zhi-qiang Jiang - One of the best experts on this subject based on the ideXlab platform.
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Combination of RAFT and Pd(II)-Initiated Isocyanide Polymerizations: A Versatile Method for Facile Synthesis of Helical Poly(Phenyl Isocyanide) Block and Star Copolymers
Macromolecules, 2018Co-Authors: Zhi-qiang Jiang, Song-qing Zhao, Na LiuAbstract:We report a new method for facile synthesis of block and star copolymers composed of helical poly(Phenyl Isocyanide) and polyacrylate segments via combination of Pd(II)-initiated Isocyanide polymerization and reversible addition–fragmentation chain transfer (RAFT) controlled radical polymerization. First, an alkyne–Pd(II) complex containing benzyl trithiocarbonate substituent was designed and synthesized. The Pd(II) moiety of the complex can catalyzed the living polymerization of Phenyl Isocyanides, while the benzyl trithiocarbonate unit can be used as a chain transfer agent for RAFT polymerization. Upon combination of the two living polymerizations, a series of block copolymers containing poly(Phenyl Isocyanide) and polyacrylate, poly(aryl vinyl) blocks with expected molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns) can be facilely prepared under controlled manner. Some of these block copolymers exhibited interesting self-assembly and stimuli-responsive properties. Taking advanta...
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Synthesis of core cross-linked star polymers carrying helical poly(Phenyl Isocyanide) arms via “core-first” strategy and their surface chiral recognition ability
Polymer, 2018Co-Authors: Qian Wang, Zhi-qiang Jiang, Li Zhou, Jian Huang, Na LiuAbstract:Abstract A norbornene functionalized alkyne-Pd(II) complex was designed and synthesized, which copolymerized with a bisnorbornene cross linker via ring-opening metathesis polymerization (ROMP) afforded a cross-linked Pd(II) macroinitiator. Living polymerization of Phenyl Isocyanides with the Pd(II) macroinitiator lead to the formation of well-defined core cross-linked star polymer carrying helical poly(Phenyl Isocyanide)s arms. Because of the living nature of Pd(II)-initiated Phenyl Isocyanide polymerization, a series of star polymers with controlled structure and tunable compositions was readily prepared. Optically active star polymers with excess of one handed helical arms were obtained by using enantiopure Phenyl Isocyanide monomers. Such star polymer exhibited excellent chiral recognition ability. The contact angle of the star polymer is strongly dependent on the chirality of the D/L-Phenylglycinol droplets. The enantioselective surface recognition can be further applied to the chiral resolution of racemic D/L-Phenylglycinol. The enantiomeric excess (ee) of the isolated enantiomer is up to 75%. The chiral star polymers can also be used to induce enantioselectively crystallization of racemic Boc-alanine. The ee value of the induced enantiomer can be up to 91%.
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Combination of RAFT and Pd(II)-Initiated Isocyanide Polymerizations: A Versatile Method for Facile Synthesis of Helical Poly(Phenyl Isocyanide) Block and Star Copolymers
2018Co-Authors: Zhi-qiang Jiang, Song-qing Zhao, Na LiuAbstract:We report a new method for facile synthesis of block and star copolymers composed of helical poly(Phenyl Isocyanide) and polyacrylate segments via combination of Pd(II)-initiated Isocyanide polymerization and reversible addition–fragmentation chain transfer (RAFT) controlled radical polymerization. First, an alkyne–Pd(II) complex containing benzyl trithiocarbonate substituent was designed and synthesized. The Pd(II) moiety of the complex can catalyzed the living polymerization of Phenyl Isocyanides, while the benzyl trithiocarbonate unit can be used as a chain transfer agent for RAFT polymerization. Upon combination of the two living polymerizations, a series of block copolymers containing poly(Phenyl Isocyanide) and polyacrylate, poly(aryl vinyl) blocks with expected molecular weights (Mns) and narrow molecular weight distributions (Mw/Mns) can be facilely prepared under controlled manner. Some of these block copolymers exhibited interesting self-assembly and stimuli-responsive properties. Taking advantage of this synthetic approach, core cross-linked star block copolymer carrying polyacrylate-block-polyIsocyanide arms can be readily prepared through the copolymerization with a cross-linker, ethylene glycol dimethacrylate. Moreover, miktoarm star copolymers carrying helical polyIsocyanides and polyacrylates arms can also be prepared under controlled manner
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One-Pot Synthesis, Stimuli Responsiveness, and White-Light Emissions of Sequence-Defined ABC Triblock Copolymers Containing Polythiophene, Polyallene, and Poly(Phenyl Isocyanide) Blocks
Macromolecules, 2017Co-Authors: Na Liu, Li Yang, Zhi-qiang JiangAbstract:A family of sequence-defined ABC triblock copolymers composed of poly(3-hexylthiophene) (P3HT), poly(hexadecyloxylallene) (PHA), and poly(Phenyl Isocyanide) (PPI) blocks were facilely synthesized in one pot using Ni(II) complex as a single catalyst. Although the monomers of the three blocks are different than each other and were polymerized under distinct polymerization mechanisms, the one-pot sequential block copolymerization was revealed to proceed in a living/controlled chain-growth manner. The sequence of the blocks can be facilely tuned through the variation on the order of monomer feed additions. Thus, a series of triblock copolymers with defined sequences, controlled molecular weights (Mns), narrow molecular weight distributions (Mw/Mns), and tunable compositions can be readily prepared just by varying the initial feed ratios of monomers to the catalyst. Taking advantage of this synthetic method, amphiphilic triblock copolymers containing hydrophobic P3HT, hydrophilic poly(triethylene glycol allene...
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Grafting polymerization of single-handed helical poly(Phenyl Isocyanide)s on graphene oxide and their application in enantioselective separation
Journal of Polymer Science Part A: Polymer Chemistry, 2017Co-Authors: Yi Xiao, Zhi-qiang Jiang, Jun Yin, Hui-qing Wang, Hao Zhang, Ya-qi Wang, Yuan-yuan ZhuAbstract:We herein report a “grafting from” strategy to immobilize optically active helical poly(Phenyl Isocyanide)s onto graphene oxide (GO) nanosheets. After covalently bounding alkyne-Pd(II) initiator onto GO nanosheets, the designed GO/polymer composites P1@GO and P1-b-P2@GO featuring single-handed helical poly(Phenyl Isocyanide)s growing from GO nanosheets were prepared by sequential addition of the chiral and achiral Isocyanide monomers. Post-synthetic hydrolysis rendered P1-b-P3@GO to improve the hydrophilicity. The successful covalent bonding of poly(Phenyl Isocyanide)s chains onto GO nanosheets was certified by several cross evidences including scan emission microscopy, atomic force microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. Circular dichroism spectra proved that the chiral information was introduced through the grafted single-handed helical polymer chains successfully. In addition, the resulting GO/polymer composites were explored as a chiral additive to induce enantioselective crystallization of racemic organic molecules. Preferential formation of rod-like L-alanine crystals was induced by composites bearing right-handed helical poly(Phenyl Isocyanide)s. The enantiomeric excess value of the induced crystals reached 76%, displaying the potential in future applications. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 2092–2103
Qian Wang - One of the best experts on this subject based on the ideXlab platform.
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Fabrication of thermoresponsive magnetic micelles from amphiphilic poly(Phenyl Isocyanide) and Fe3O4 nanoparticles for controlled drug release and synergistic thermochemotherapy
Polymer Chemistry, 2021Co-Authors: Qian Wang, Jing Xiao, Jianwen Huang, Lige Qiu, Meixiao Zhan, Weizhong YuanAbstract:The drug-loaded micelles self-assembled from co-poly(Phenyl Isocyanide), Fe3O4 and DOX demonstrated thermoresponsiveness and magnetic hyperthermia for synergistic thermochemotherapy.
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Facile Synthesis of Optically Active and Thermoresponsive Star Block Copolymers Carrying Helical PolyIsocyanide Arms and Their Thermo-Triggered Chiral Resolution Ability
ACS Macro Letters, 2018Co-Authors: Qian Wang, Ben-fa Chu, Jia-hong Chu, Na LiuAbstract:A left-handed helical poly(Phenyl Isocyanide) bearing a norbornene unit and a Pd(II) complex on each terminus was prepared. The norbornene terminus was core cross-linked with a bisnorbornene linker via ring-opening metathesis polymerization (ROMP), yielding a star polymer carrying left-handed helical arms decorated with Pd(II) units at the exterior. The optical activities of the helical arms were maintained after the cross-linking reaction. The Pd(II) units on the surface of the star polymer were chain extended with a new Phenyl Isocyanide bearing three hydrophilic triethylene glycol monomethyl chains, which afforded an amphiphilic star block copolymer carrying helical arms. Such a star block copolymer showed excellent thermoresponsiveness with the lower critical solution temperature (LCST) around 55 °C. This optically active and thermoresponsive star polymer can enantioselectively capture the S-enantiomer of racemic methyl benzyl alcohol solution at a temperature lower than the LCST and precipitated when...
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Synthesis of core cross-linked star polymers carrying helical poly(Phenyl Isocyanide) arms via “core-first” strategy and their surface chiral recognition ability
Polymer, 2018Co-Authors: Qian Wang, Zhi-qiang Jiang, Li Zhou, Jian Huang, Na LiuAbstract:Abstract A norbornene functionalized alkyne-Pd(II) complex was designed and synthesized, which copolymerized with a bisnorbornene cross linker via ring-opening metathesis polymerization (ROMP) afforded a cross-linked Pd(II) macroinitiator. Living polymerization of Phenyl Isocyanides with the Pd(II) macroinitiator lead to the formation of well-defined core cross-linked star polymer carrying helical poly(Phenyl Isocyanide)s arms. Because of the living nature of Pd(II)-initiated Phenyl Isocyanide polymerization, a series of star polymers with controlled structure and tunable compositions was readily prepared. Optically active star polymers with excess of one handed helical arms were obtained by using enantiopure Phenyl Isocyanide monomers. Such star polymer exhibited excellent chiral recognition ability. The contact angle of the star polymer is strongly dependent on the chirality of the D/L-Phenylglycinol droplets. The enantioselective surface recognition can be further applied to the chiral resolution of racemic D/L-Phenylglycinol. The enantiomeric excess (ee) of the isolated enantiomer is up to 75%. The chiral star polymers can also be used to induce enantioselectively crystallization of racemic Boc-alanine. The ee value of the induced enantiomer can be up to 91%.
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Facile Synthesis of Optically Active and Thermoresponsive Star Block Copolymers Carrying Helical PolyIsocyanide Arms and Their Thermo-Triggered Chiral Resolution Ability
2018Co-Authors: Qian Wang, Ben-fa Chu, Jia-hong Chu, Na LiuAbstract:A left-handed helical poly(Phenyl Isocyanide) bearing a norbornene unit and a Pd(II) complex on each terminus was prepared. The norbornene terminus was core cross-linked with a bisnorbornene linker via ring-opening metathesis polymerization (ROMP), yielding a star polymer carrying left-handed helical arms decorated with Pd(II) units at the exterior. The optical activities of the helical arms were maintained after the cross-linking reaction. The Pd(II) units on the surface of the star polymer were chain extended with a new Phenyl Isocyanide bearing three hydrophilic triethylene glycol monomethyl chains, which afforded an amphiphilic star block copolymer carrying helical arms. Such a star block copolymer showed excellent thermoresponsiveness with the lower critical solution temperature (LCST) around 55 °C. This optically active and thermoresponsive star polymer can enantioselectively capture the S-enantiomer of racemic methyl benzyl alcohol solution at a temperature lower than the LCST and precipitated when the temperature was higher than the LCST, leaving the R-enantiomer in the solution. The enantiomeric excess (ee) of the isolated enantiomer is up to 75%
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Helix-Sense-Selective and Enantiomer-Selective Living Polymerization of Phenyl Isocyanide Induced by Reusable Chiral Lactide Using Achiral Palladium Initiator
Macromolecules, 2015Co-Authors: Jia-li Chen, Zhi-qiang Jiang, Na Liu, Jun Yin, Li Yang, Qian Wang, Yunsheng DingAbstract:Polymerization of Phenyl Isocyanide using achiral Pd(II) initiator with the presence of chiral l- or d-lactide (l-LA or d-LA) as additive was found to proceed in helix-sense-selective manner. The polymerization of achiral Phenyl Isocyanide, 4-isocyanobenzoyl-2-aminoisobutyric acid decyl ester (1) by this method produced optically active helical poly-1m(L), whose chirality was solely come from the helical conformation without containing of any other chiral atoms. The added chiral LA can be facilely recovered and reused in the helix-sense-selective polymerizations without significantly loss of its chiral induction, and the chiral economy of the polymerization is high. When enantiomerically pure Phenyl Isocyanide bearing an R- or S-alanine pendent with a long n-decyl chain (1r or 1s) were polymerized by this method, the polymerization was found to proceed in a highly enantiomer-selective manner with one of the enantiomers preferentially polymerized over the antipode by a factor of 3.6. Single-handed helical ...