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Trinuclear gold-catalyzed site-selective alkylation of peptides

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Science china chemistry 2024年

作者： Qingyun Fang Chengyihan Gu Yinghan Chen Wencheng yan Yong Liang Weipeng Li Chengjian Zhu Jie Han Jin Xie state key laboratory of coordination chemistry Jiangsu Key Laboratory of Advanced Organic MaterialsChemistry and Biomedicine Innovation Center (ChemBIC)School of Chemistry and Chemical EngineeringNanjing University Green Catalysis Center College of ChemistryZhengzhou University state key laboratory of Natural Medicines China Pharmaceutical University

Selective modification of peptides has always been a challenging *** selective alkylation of peptides can alter the biological activity and physical properties of molecules,and it has gained significant research *** herein disclose an intriguing gold-catalyzed alkylation of peptides using bench-stable unactivated alkyl bromides under photoredox catalysis.A wide range of structurally diverse primary,secondary and tertiary alkyl bromides serve as effective coupling partners to precisely connect with the α-C(sp3)–H in glycine residue of *** protocol demonstrates an exceptionally broad scope for alkyl halides and excellent tolerance for a wide range of useful functional groups.A series of relay transformations to construct cyclic peptides,to proceed click reaction and to realize peptide fluorescence labeling further enhance its synthetic *** addition,mechanistic studies and density functional theory (DFT) calculations reveal an inner-sphere and subsequent outersphere single electron transfer (SET) mechanism.

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Syntheses and Crystal Structures of Five Sr^(Ⅱ)-Ln^(Ⅲ)(Ln=Nd,Pr,Er) Heterometallic coordination Polymers

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Chinese Journal of Structural chemistry 2013年第12期32卷 1859-1867页

作者： CAO yan-Yuan CHEN yan-Mei LIU Wei LI Ya-hong key laboratory of Organic Synthesis of jiangsu Province College of ChemistryChemical Engineering and Materials ScienceSoochow University

Five novel SrⅡ-LnⅢ heterometallic coordination polymers based on pyridine-2,6- dicarboxylic acid （H2pda） and imidazole （im）, namely, [LnSr（pda）3（H2O）5]-Him·C2H5OH·3H2O （Ln = Nd （1）; Pr （2））, [Ln2Sr（pda）6（H2O）5]-4Him·C2H5OH·5H2O （Ln = Nd （3）; Pr （4））, and [ErSr（pda）3（H2O）4].Him-3.5H2O （5）, have been prepared and structurally characterized. X-ray crystallographic analyses revealed that these complexes display three varieties of l-D chain structures. Several types of hydrogen bonding interactions are found for 1-5, which connect the 1 -D chain structures to form 2-D suoramolecular networks.

关键词： heterometallic coordination polymers strontium lanthanide crystal structure

chemical inhomogeneity inhibits grain boundary fracture:A comparative study in CrCoNi medium entropy alloy

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Journal of Materials Science & Technology 2023年第22期153卷 228-241页

作者： Fuhua Cao yan Chen Hai-Ying Wang Lan-hong Dai state key laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China school of engineering Science University of Chinese Academy of SciencesBeijing 101408China school of Future Technology University of Chinese Academy of SciencesBeijing 100049China

Grain boundary(GB)fracture is arguably one of the most important reasons for the catastrophic failure of ductile polycrystalline *** is of interest to explore the role of chemical distribution on GB defor-mation and fracture,as GB segregation becomes a key strategy for tailoring GB *** we report that the inhomogeneous chemical distribution effectively inhibits GB fracture in a model CoCrNi medium entropy alloy compared to a so-called‘average-atom’*** deformation kinematics combined with electronic behavior analysis reveals that the strong charge redistribution ability in chemical disor-dered CrCoNi GBs enhances shear deformation and thus prevents GB crack formation and *** on the GBs with different chemical components and chemical distributions suggest that not only disordered chemical distribution but also sufficient“harmonic elements”with large electronic flexibility contribute to improving the GB fracture *** study provides new insight into the influence mechanism of GB chemistry on fracture behavior,and yields a systematic strategy and criterion,from the atoms and electrons level,forward in the design of high-performance materials with enhanced GB fracture resistance.

关键词： Fracture chemical inhomogeneity Grain boundary Medium entropy alloy

Synthesis of cationic hyperbranched multiarm copolymer and its application in self-reducing and stabilizing gold nanoparticles

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Science china chemistry 2010年第5期53卷 1113-1120页

作者： Zhai, Shuo hong, Haiyan Zhou, YongFeng yan, DeYue state key laboratory of Metal Matrix Composites College of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China

A novel hyperbranched multiarm copolymer of HBPO-star-PDEAEMA with a hydrophobic poly(3-ethyl-3-(hydroxymethyl) oxetane)(HBPO) core and many cationic poly(2-(N,N-diethylamino) ethyl methacrylate)(PDEAEMA) arms has been synthesized through an atom transfer radical polymerization(ATRP) method,and been applied to spontaneously reduce and stabilize gold nanoparticles(AuNPs) in water without other additional *** size of the nanoparticles could be effectively controlled at about 4 nm,and the nanoparticles are extremely stable in solution without aggregation even for one *** was found that solution pH and the molar ratio of N/Au have certain effects on the size and stability of *** work provides a simple method for the synthesis of uniform and highly stable AuNPs.

关键词： gold nanoparticles hyperbranched polymers self-reduction stabilization

Studies of n-Octanol/water Partition Coefficients (lgK_(ow)) for Organophosphate Compounds by Density Functional Theory

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Chinese Journal of Structural chemistry 2007年第3期26卷 367-373页

作者： LIU hong-Xia WANG Zun-Yao ZHAI Zhi-Cai LIU hong-yan WANG Lian-Sheng Department of Material and chemical engineering Guilin Institute of Technology Guangxi 541004 China school of Biological and chemical engineering Jiaxing University Zhejiang 314001 China state key laboratory of Pollution Control and Resources Reuse School of the Environment Nanjing University Nanjing 210093 China

Optimized calculation of 35 dialkyl phenyl phosphate compounds （OPs） was carded out at the B3LYP/6-31G^＊ level in Gaussian 98 program. Based on the theoretical linear solvation energy relationship （TLSER） model, the obtained parameters were taken as theoretical descriptors to establish the novel QSPR model for predicting n-octanol/water partition coefficients （lgKow） of OPs. The new model achieved in this work contains three variables, i.e., molecular volume （Vm）, dipole moment of the molecules （μ） and enthalpy （H^0）. For this model, R^2 = 0.9167 and SD = 0.31 at large t values. In addition, the variation inflation factors （VIF） of variables are all close to 1.0, suggesting high accuracy of the predicting model. And the results of cross-validation test （q^2 = 0.8993） and method validation also showed the model of this study exhibited optimum stability and better predictive power than that from semi-empirical method. The model achieved can be used to predict IgKow of congeneric compounds.

关键词： organophosphate compounds (OPs) n-octanol/water partition coefficients (Kow) quantitative structure-property relationship (QSPR) density functional theory (DFT)

The Effect of Trifluoroacetic Acid on Molecular Weight Determination of Polyesters:An in Situ NMR Investigation

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Chinese Journal of Polymer Science 2021年第12期39卷 1590-1596页

作者： yan-yan Tu Xue-Ting Wan Jie Huan Xiang Zhu Xiao-hong Li Ying-Feng Tu state and Local Joint engineering laboratory for Novel Functional Polymeric Materials College of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhou 215123China

Due to the poor solubility of aromatic polyesters in comm on orga nic solve nts,trifluoroacetic acid is usually used as a co-solve nt to increase their solubility for ***,only few studies have reported the side reactions induced by *** present here the application of in situ 1H-NMR techniques to explore its effect on the hydroxyl end-groups,which are usually used for the molecular weight determination of polyesters by end-group estimation *** bis(2-hydroxyethyl)terephthalate(BHET)as model compound,quantitative NMR results show the peak integration of hydroxyethyl end-groups decreased with time via a pseudo-first-order kinetics in d-trifluoroacetic acid/d-chloroform mixture solvent(1:10,V:V).This is due to the esterification of hydroxyethyl groups with trifluoroacetic acid,revealed by the H-^(13)C gradient-enhanced heteronuclear multiple bond correlation(gHMBC)*** mixtures of dimethyl terephthalate and BHET with different molar ratios were used to represent poly(ethylene terephthalate)(PET)with different degrees of polymerization,and the effect of trifluoroacetic acid on the estimation of hydroxyethyl groups and subsequent molecular weight determination of polyesters was *** results show that if a relative error of 5%is allowed,the NMR measurements must be finished within 1.3 h of solution preparation at 25℃ in the mixture solve *** results were confirmed in PET sample,while in poly(ethyle ne adipate),the obtained esterifaction con stant is faster that those in aromatic *** results can be applied to other polymer systems with alcohol functionalized groups,and used as a guideline for the characterization of polyesters and polyethers by end-group estimation method.

关键词： Polyesters NMR spectroscopy Trifluoroacetic acid Molecular weight

Superlubricity by polyimide-induced alignment

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Friction 2023年第9期11卷 1690-1707页

作者： Xinlei GAO Hao CHEN hong yan Chengrui HUANG Li WU Tingting WANG school of Materials Science and engineering Hubei UniversityWuhan 430062China school of chemical and Environmental engineering Wuhan Polytechnic UniversityWuhan 430023China state key laboratory of chemical Resource engineering College of ChemistryBeijing University of Chemical TechnologyBeijing 100029China school of chemistry and Environmental engineering Wuhan Institute of TechnologyWuhan 430074China

We have investigated the lubrication alignment behavior of point–plane contact and plane–plane contact between the GCr15 steel and polyimide(PI)friction pair using nematic liquid crystals(LCs)as the *** this system,rubbing orients the macromolecular PI molecules,and the oriented PI molecules induce alignment of the LC molecules in contact with or close to the oriented PI *** LC molecules are aligned in the wear scar grooves of the PI film,and alignment extends to the GCr15-steel *** of the LC molecules is correlated with the strong interaction force between the PI and LC molecules,the stable coordination structure of the LCs and GCr15 steel,and the weak interaction between the LC *** performed simulations of the pretilt angle of PI and LCs and discussed the relationship between the pretilt angle and the friction *** to the small pretilt angle between PI and the LCs,the LC molecules orient almost parallel to the PI material,which is beneficial for superlubricity of this type of friction system.

关键词： superlubricity polyimide liquid crystal alignment

Multifunctional catalytic sites regulation of atomic-scale iridium on orthorhombic-CoSe_(2)for high efficiency dual-functional alkaline hydrogen evolution and organic degradation

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Journal of Energy chemistry 2024年第5期92卷 271-281页

作者： Jingjing Huang Chenglin Zhong yanjie Xia Jia Liu Guizhen Li Chao yang Jiahong Wang Qian Wang Zhenbao Zhang Feng yan Jianghua Wu Yu Deng Zhenjiang Zhou Xingchen He Paul K.Chu Woon-Ming Lau Xue-Feng Yu College of chemistry and chemical engineering Linyi UniversityLinyi 276005ShandongChina Shenzhen engineering Center for the Fabrication of Two-Dimensional Atomic Crystals Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055GuangdongChina National laboratory of Solid state Microstructures Jiangsu Key Laboratory of Artificial Functional MaterialsCollege of Engineering and Applied Sciences and Collaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093JiangsuChina College of Biosystems engineering and Food Science Zhejiang UniversityHangzhou 310058ZhejiangChina Department of Physics Department of Materials Science and EngineeringDepartment of Biomedical EngineeringCity University of Hong KongTat Chee AvenueKowloonHong KongChina

The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was *** hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) *** the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co *** was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting *** was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.

关键词： Orthorhombic-CoSe_(2) Multifunctional sites design Hydrogen evolution reaction Synergistically catalyze Methylene blue oxidation

Synthesis and Photoelectric Properties of New Pr-bonded Polymers by coordination of Isopropyloxide and Bipyridine Unit

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Chinese Journal of Polymer Science 2017年第3期35卷 342-353页

作者： wei lv 王文 chun-lei zhang yan zhao hong-yu zhen 凌启淡 College of chemistry and chemical engineering College of Materials Science and EngineeringFujian Normal University Fujian Key Laboratory of Polymer Materials Fuzhou 350007 China

A series of novel praseodymium（Pr）-bonded polymers were successfully synthesized via the coordination reaction and palladium-catalyzed Suzuki coupling reaction of 2,7-dibromo-9,9’-dioctylfluorene and different amounts of 5,5’-dibromo-2,2’-bipyridine. The resulting polymers were characterized by;H-NMR and GPC. The photoluminescence（PL） and electroluminescence（EL） properties of the resulting polymers were studied to explore the effects of the Pr triisopropyloxide. The results showed that the incorporation of Pr into the polymers caused better coplanarity and effective intermolecular or intramolecular interaction, leading to the higher emission intensity at long-wavelength. Further, it was also found that the emission light color could be tuned from blue to green by introduction of a small amount of Pr into the polymer main chain. A single-layer green emitting EL device based on PF（Bipy Pr）6 with 6 mol% Pr content was fabricated. The device had a low turn-on voltage of 6 V, a brightness of 705.3 cd·m;, the maximum luminous efficiency of 1.53 cd·A;and the maximum power efficiency of 0.69 lm·W;.

关键词： Polyfluorene Praseodymium Light-emitting polymers Bipyridine