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Differentiation Effect of Pentacoordinate Phosphorus on Carbohydrate Reaction
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作者 Yong JU Yi CHEN +1 位作者 Yu Fen ZHAO (Bioorganic Phosphorus Chemistry Laboratory. Department of Chemistry.Tsinghua University. Beijing 100084) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第5期387-388,共2页
The reaction between D-glucose, D-ribose and 2, 2,2-trimethoxy-4, 5-diphenyl-2, 2-dihydro-1, 3, 2-dioxaphospholene were investigates by P-31 NMR and FAB-MS. The results showed that there were a lot of differences in t... The reaction between D-glucose, D-ribose and 2, 2,2-trimethoxy-4, 5-diphenyl-2, 2-dihydro-1, 3, 2-dioxaphospholene were investigates by P-31 NMR and FAB-MS. The results showed that there were a lot of differences in the reactions via pentacoordinate phosphorus compound, and it should give it significant clue to the metabolism of carbohydrate phosphate in nature. 展开更多
关键词 CARBOHYDRATE pentacoordinate oxyphosphorane biomimic mechanism
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Synthesis of Aminoacyl Adenylate Pentacoordinated Phosphorus Compounds
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《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期197-197,共1页
关键词 LI Synthesis of Aminoacyl Adenylate pentacoordinated Phosphorus Compounds
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Pentacoordinated Spirophosphoranes from Amino Acid Sodium Salts
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作者 Hai Yan LU Nan Jing ZRANG Yu Fen ZRAO(Bioorganic Phosphorus Chemistry Laboratory, Dcyartinen of ChemistryTsinghua Uhiverslty, Beijing, 100084) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第5期397-400,共4页
The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques. The results show... The reactions of 2-chloro-1,3,2-dioxaphospholane with various sodium salts of amino acids to afford the pentacoordinated spirophosphoranes containing amino acid were studied by NMR spectra techniques. The results showed that natural alpha-amino acids had greater ability than beta-amino acids to form the pentacoordinated species, which is important in the biosynthesis and prebiotic synthesis of of oligopeptides and proteins. 展开更多
关键词 pentacoordinated Spirophosphoranes from Amino Acid Sodium Salts LI
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Formation of Oligosaccharide from Monosaccharide by Pentacoordinate Oxyphosphorane
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作者 Dong Yan QIN Yong JU +2 位作者 Yu GUO Yu Fen ZHAO Qin Zhu WANG(Bioorganic Phosphorus Chemistry Labothory, Department of Chemistry, Tsinghua University, Beijing 100084) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第4期303-304,共2页
Oxyphosphorane reacted with glucose to give disaccharide which was confirmed by FAB-MS and C-13-NMR. The mechanism for formation of oligosaccharides through the participation of phosphorus was proposed.
关键词 Formation of Oligosaccharide from Monosaccharide by pentacoordinate Oxyphosphorane
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Synthesis and Characterization of Stereoismers of Pentacoordinated Phosphorus Compounds
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《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期206-206,共1页
关键词 Synthesis and Characterization of Stereoismers of pentacoordinated Phosphorus Compounds
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Pentacoordinate Phosphoranes as Versatile Reagents in Fluoroalkylation Reactions
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作者 Huanhuan Song Weihao Li +7 位作者 Xiaoying Wang Kaiteng Wang Jingwen Li Shuai Liu Pin Gao Xin-Hua Duan Jinbo Hu Mingyou Hu 《CCS Chemistry》 CSCD 2024年第1期165-176,共12页
A general method for the synthesis of bench-stable bis(difluoromethyl)pentacoordinate phosphoranes has been developed.The reaction is rapid,operationally simple,and easily scalable.The pentacoordinate phosphoranes can... A general method for the synthesis of bench-stable bis(difluoromethyl)pentacoordinate phosphoranes has been developed.The reaction is rapid,operationally simple,and easily scalable.The pentacoordinate phosphoranes can generate both difluoromethyl radical(·CF_(2)H)and difluorocarbene(:CF_(2))intermediates.Thus,a variety of fluoroalkylation transformations havebeen achieved by·CF_(2)H,such asoxidativedifluoromethylation of electron-deficient heterocycles,nickel/photoredox dual-catalyzed difluoromethylation of aryl bromides,and photoredox difluoromethylation of alkenes,or by:CF_(2),such as gem-difluorocyclopropanation of alkenes,base-promoted difluoromethylation of heteroatom nucleophiles,Pd-catalyzed difluoromethylation of arylboronic acids,and Cu-mediated trifluoromethylation of aryl iodides(via:CF_(2) and recombined CF_(3)-).These fluoroalkylation methods have been successfully applied to late-stage fluoroalkylation of drugs and drug-like molecules. 展开更多
关键词 pentacoordinate phosphorane difluoromethyl radical DIFLUOROCARBENE DIFLUOROMETHYLATION FLUOROALKYLATION
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The role of pentacoordinate Al^(3+)sites of Pt/Al_(2)O_(3)catalysts in propane dehydrogenation
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作者 Yan Wang Chunlei Pei +3 位作者 Xianhui Wang Guodong Sun Zhi-Jian Zhao Jinlong Gong 《Fundamental Research》 CSCD 2024年第6期1480-1487,共8页
Pentacoordinate Al^(3+)(Al^(3+)_(penta))sites on alumina(Al_(2)O_(3))could anchor and stabilize the active site over the cata-lyst surface.The paper describes the specific effect of Al^(3+)_(penta) sites on the struct... Pentacoordinate Al^(3+)(Al^(3+)_(penta))sites on alumina(Al_(2)O_(3))could anchor and stabilize the active site over the cata-lyst surface.The paper describes the specific effect of Al^(3+)_(penta) sites on the structure and the catalytic performance of Al_(2)O_(3)supported Pt catalysts by modulating the quantity of Al^(3+)_(penta) sites.The Al^(3+)_(penta) site content of Al_(2)O_(3)exhibits a volcano-type profile as a function of calcination temperature due to the structural rearrangement.The loading of Pt and subsequent calcination can consume a significant portion of Al^(3+)_(penta) sites over the Al_(2)O_(3)support.We further find that,when the calcination temperature of the impregnated Al_(2)O_(3)is higher than the cal-cination temperature of Al_(2)O_(3)precursor,the structural rearrangement of Al^(3+)_(penta) sites could make Pt partially buried in Al_(2)O_(3).Consequently,this partially buried structure leads to relatively low conversion but high stability for propane dehydrogenation.This work further elucidates the stabilization mechanism of the Al^(3+)_(penta) site over Al_(2)O_(3)support. 展开更多
关键词 Propane dehydrogenation Anchoring effect Pt/Al_(2)O_(3) pentacoordinate Al^(3+)sites Metal-support interaction
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High-throughput theoretical exploration of multifunctional planar MBenes: Magnetism, topology, superconductivity, and anode applications
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作者 Xiaodong Lv Ting Han +3 位作者 Rong Liu Fengyu Li Jian Gong Zhongfang Chen 《Advanced Powder Materials》 2025年第3期78-89,共12页
Pursuing new two-dimensional(2D)materials has been a hot topic in materials science,driven by their potential for diverse applications.Recent research has unveiled stable planar hypercoordinate motifs with unconventio... Pursuing new two-dimensional(2D)materials has been a hot topic in materials science,driven by their potential for diverse applications.Recent research has unveiled stable planar hypercoordinate motifs with unconventional geometric arrangements and bonding patterns that facilitate the synthesis of new 2D materials with diverse applications.Among these,yet the design of 2D transition metal systems featuring planar pentacoordinate boron(ppB)is particularly intriguing.Here we address this gap by proposing a novel family of transition metal boride monolayers(MBenes)composed of ppB and heptacoordinate M motifs.The novelty of our MBenes stems from their distinct atomic arrangements and bonding configurations,setting them apart from traditional 2D materials.High-throughput calculations identified 10 stable MBenes(with the stoichiometry of MB,M=Cr,Fe,Co,Ni,Cu,Mo,Pd,Ag,Pt,Au)with exceptional thermodynamic,dynamic,thermal,and mechanical stabilities attributed to strong BB covalent bonds and MB ionic interactions.Notably,five of these MBenes(M=Ni,Pd,Pt,Ag,Au)hold high promise as topological superconducting materials with superconducting transition temperatures of 2.4-5.2 K.This discovery not only enriches the family of topological superconducting materials but also opens new avenues for quantum device development.Meanwhile,FeB monolayer exhibits robust ferromagnetic properties with a high Curie temperature of~750 K,which is particularly significant for spintronics applications.In addition,NiB and CuB MBenes demonstrate extremely low sodium diffusion barriers(about 30 and 90 meV)and high sodium storage capacities(788 and 734 mAh g1,respectively),making them promising anode materials for sodium-ion batteries(SIBs).This study expands the selection of electrode materials for SIBs and mitigates some existing limitations in battery technology.Overall,these findings underscore the multifunctional potential of MBenes,positioning them as transformative materials for quantum computing,spintronics,and energy storage applications. 展开更多
关键词 MBenes Planar pentacoordinate boron Stability FERROMAGNETIC Topological superconducting Anode materials
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Theoretical observation of hexaatomic molecules containing pentacoordinate planar carbon 被引量:6
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作者 LUO Qiong State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China 《Science China Chemistry》 SCIE EI CAS 2008年第11期1030-1035,共6页
The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic fac... The smallest molecules up to date containing a D5h pentacoordinate planar carbon (PPC) atom, CBe5 and CBe54-, are presented by means of ab initio calculations. To gain a better understanding about which electronic factors contribute to their stabilization, natural bond orbital (NBO) analysis and the nucleus independent chemical shifts (NICS) were calculated. The data reported here suggest that D5h CBe5 is σ aromaticity in nature, while in D5h CBe54- π aromaticity is dominating. The classical octet rule is well satisfied in both molecules, and is one of the fundamental reasons to understand the stability of the pentagon structures. The Be5 ring serves as σ donor in D5h CBe5, and π-acceptor in D5h CBe54-. The D5h CBe54- possessing 18 valence electrons with a closed-shell electron configuration is the most plau-sible candidate for experimental detection. 展开更多
关键词 pentacoordinate PLANAR CARBON Be5 ring ab INITIO
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High population and dispersion of pentacoordinated Al~Ⅴ species on the surface of ?ame-made amorphous silica-alumina 被引量:3
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作者 Zichun Wang Yijiao Jiang +9 位作者 Xianfeng Yi Cuifeng Zhou Aditya Rawal James Hook Zongwen Liu Feng Deng Anmin Zheng Michael Hunger Alfons Baiker Jun Huang 《Science Bulletin》 SCIE EI CAS CSCD 2019年第8期516-523,共8页
Pentacoordinated Al(Al~Ⅴ)species in silica-alumina are promising to promote the formation of acid sites or act as surface defects for tailoring single-atom catalysts.However,pentahedral coordination(Al~Ⅴ)is rarely o... Pentacoordinated Al(Al~Ⅴ)species in silica-alumina are promising to promote the formation of acid sites or act as surface defects for tailoring single-atom catalysts.However,pentahedral coordination(Al~Ⅴ)is rarely observed in conventionally prepared silica-alumina.Here,we show that high population and dispersion of Al~Ⅴ species on the surface of amorphous silica-alumina(ASA)can be achieved by means of flame spray pyrolysis.High resolution TEM/EDX,high magnetic-field NMR and DFT calculations are employed to characterize the structure of as-prepared ASAs.Solid-state ^(27)Al multi-quantum MAS NMR experiments show that most of the Al~Ⅴspecies are formed independently from the alumina phase and are accessible for vip molecules on the surface.Upon water adsorption,these Al~Ⅴ species are transformed to Al~Ⅵ species,structurally similar to surface Al~Ⅳ species,as confirmed by DFT calculations.The outstanding catalytic activity of as-synthesized ASA is demonstrated using the in situ H/D exchange reaction with deuterated benzene as an example.The Al~Ⅴ-rich ASA provides a much lower activation energy(~30 kJ/mol)than that reported for zeolite H-ZSM-5(~60 kJ/mol).The superior catalytic performance is attributed to the high Al~Ⅴcontent promoting the surface active sites in ASA.The knowledge gained on the synthesis of Al~Ⅴ-rich ASAs and the nature of aluminum coordination in these materials could pave the way to more efficient silica-alumina based catalysts. 展开更多
关键词 AMORPHOUS SILICA-ALUMINA pentacoordinated Al~Ⅴ SPECIES 27Al multiple quantum magic-angle-spinning NMR H/D exchange
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Electrospray Ionization Mass Spectra of Amino Acid Methyl Ester 5′-Phosphoramidates of 2′,3′-Isopropylideneuridine
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作者 CHEN Wei-zhu GAO Yu-xing +2 位作者 BAI Yong-gang HAN Da-xiong ZHAO Yu-fen 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2006年第6期732-737,共6页
Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode dectrospmy ionization mass spectrometry(ESIMS) in combination with multistage tandem mass spectrometry. The fragmentation... Amino acid methyl ester phosphates were synthesized and determined by using positive-ion mode dectrospmy ionization mass spectrometry(ESIMS) in combination with multistage tandem mass spectrometry. The fragmentation pathways were investigated, and it was observed that most fragment ions contained the phosphoryl group. It was interesting to observe that the fragmentation pathways of the protonated molecule show some differences when compared with those of the sodium ion adduct. The methoxy group of amino acid methyl ester can migrate from the carbonyl group to the phosphoryl group in the sodium ion adduct. 展开更多
关键词 ESIMS Fragmentation pathway Methoxy group rearrangement pentacoordinated phosphorus intermediate Amino acid methyl ester 5'-phosphoramidate of nucleoside
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Color center-richγ-Al_(2)O_(3)promotes propane dehydrogenation
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作者 Yu Wang Xiang Wang +6 位作者 Mengfei Qiao Qingyuan Wu Kunlong Liu Xiaodong Yi Ruixuan Qin Gang Fu Nanfeng Zheng 《Science China Chemistry》 SCIE EI CAS CSCD 2024年第12期4134-4141,共8页
The Pt Sn/Al_(2)O_(3)catalyst is commonly used in commercial propane dehydrogenation(PDH)processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at ... The Pt Sn/Al_(2)O_(3)catalyst is commonly used in commercial propane dehydrogenation(PDH)processes,but it faces challenges in the deactivation and periodic regeneration due to metal aggregation and coke deposition at high temperatures.Although Al_(penta)^(3+)has been proven to be beneficial for enhancing catalytic stability,bottom-up synthesis protocols usually restrict their applications.Here,a facile post-treatment approach using acetic acid was applied to create color centers(electrons trapped within oxygen vacancies)onγ-Al_(2)O_(3).Notably,the content of Al_(penta)^(3+)was enriched to 18.3%.Then,the pre-established Pt Sn clusters were loaded.The electrons facilitated the formation of ultrafine Pt Sn nanoparticles(~2 nm),and the Al_(penta)^(3+)sites prevented the sintering of Pt Sn by constructing the strong Al_(penta)^(3+)–O–Sn bonds.Furthermore,the catalytic durability of the catalyst prepared by conventional impregnation methods was remarkably extended from 186 h for the color center-free sample to 1,000 h using the HAc–Al_(2)O_(3)support.This facile post-modification was further successfully extended to commercial Al_(2)O_(3)pellets without altering their mechanical properties,highlighting its potential in industrial applications. 展开更多
关键词 catalytic stability pentacoordinate Al^(3+) PtSn catalyst metal-support interaction mechanical strength
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Decrypting the Influence of Axial Coordination on the Electronic Microenvironment of Co-N_(5)Site for Enhanced Electrocatalytic Reaction
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作者 Bingyu Huang Senhe Huang +7 位作者 Chenbao Lu Longbin Li Judan Chen Ting Hu Dirk Lützenkirchen-Hecht Kai Yuan Xiaodong Zhuang Yiwang Chen 《CCS Chemistry》 CSCD 2023年第8期1876-1887,共12页
Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configura... Metal porphyrins are star molecules that possess welldefined coordination metal centers for versatile catalytic reactions.However,most previous work has focused on the correlations between in-plane symmetric configuration of metal-N_(4)sites and their catalytic performance.Addressing the catalytic contribution of additional axial coordination to such symmetric configuration remains a challenge.Theoretical calculations revealed that axially anchoring an extra pyridine on the tetra-coordinated cobalt porphyrin(Co-N4)to construct penta-coordinated cobalt porphyrin(Co-N_(5))renders cobalt a higher electron density,thereby favoring the rate-determining O_(2)adsorption/activation and reducing the oxygen electroreduction barrier.Therefore,a well-defined Co-N_(5)site is rationally introduced into the azo-linked polymer framework for a fundamental structure-catalytic performance correlation study.As-prepared Co-N_(5)catalyst exhibits a 26 mV positive shift in half-wave potential compared with the pyridine-free Co-N_(4)counterpart,discloses a markedly higher power density(141.4 mW cm^(−2)),and possesses better long-term durability(over 160 h cycles)in a Zn-air battery.Moreover,such a Co-N_(5)catalyst also showcases potential applications for CO_(2)reduction with high CO_(2)-to-CO conversion faradic efficiency and better selectivity than the Co-N_(4)counterpart because coordination of the fifth pyridine evokes electronic localization that suppresses a competitive side reaction.This work proves the positive electrocatalytic contribution of axial penta-coordination on well-defined metalporphyrin-based catalysts and offers atomic understanding of the structure-performance correlation on single atom catalysts for future catalyst design. 展开更多
关键词 PORPHYRIN axial coordination pentacoordination structureactivity correlation oxygen reduction reaction
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