Objective:Uterine corpus endometrial carcinoma(UCEC),a kind of gynecologic malignancy,poses a significant risk to women’s health.The precise mechanism underlying the development of UCEC remains elusive.Zinc finger pr...Objective:Uterine corpus endometrial carcinoma(UCEC),a kind of gynecologic malignancy,poses a significant risk to women’s health.The precise mechanism underlying the development of UCEC remains elusive.Zinc finger protein 554(ZNF554),a member of the Krüppel-associated box domain zinc finger protein superfamily,was reported to be dysregulated in various illnesses,including malignant tumors.This study aimed to examine the involvement of ZNF554 in the development of UCEC.Methods:The expression of ZNF554 in UCEC tissues and cell lines were examined by qRT-PCR and Western blot assay.Cells with stably overexpressed or knocked-down ZNF554 were established through lentivirus infection.CCK-8,wound healing,and Transwell invasion assays were employed to assess cell proliferation,migration,and invasion.Propidium iodide(PI)staining combined with fluorescence-activated cell sorting(FACS)flow cytometer was utilized to detect cell cycle distribution.qRT-PCR and Western blotting were conducted to examine relative mRNA and protein levels.Chromatin immunoprecipitation assay and luciferase reporter assay were used to explore the regulatory role of ZNF554 in RNA binding motif 5(RBM5).Results:The expression of ZNF554 was found to be reduced in both UCEC samples and cell lines.Decreased expression of ZNF554 was associated with higher tumor stage,decreased overall survival,and reduced disease-free survival in UCEC.ZNF554 overexpression suppressed cell proliferation,migration,and invasion,while also inducing cell cycle arrest.In contrast,a decrease in ZNF554 expression resulted in the opposite effect.Mechanistically,ZNF554 transcriptionally regulated RBM5,leading to the deactivation of the Wingless(WNT)/β-catenin signaling pathway.Moreover,the findings from rescue studies demonstrated that the inhibition of RBM5 negated the impact of ZNF554 overexpression onβ-catenin and p-glycogen synthase kinase-3β(p-GSK-3β).Similarly,the deliberate activation of RBM5 reduced the increase inβ-catenin and p-GSK-3βcaused by the suppression of ZNF554.In vitro experiments showed that ZNF554 overexpression-induced decreases in cell proliferation and migration were counteracted by RBM5 knockdown.Additionally,when RBM5 was overexpressed,it hindered the improvements in cell proliferation and migration caused by reducing the ZNF554 levels.Conclusion:ZNF554 functions as a tumor suppressor in UCEC.Furthermore,ZNF554 regulates UCEC progression through the RBM5/WNT/β-catenin signaling pathway.ZNF554 shows a promise as both a prognostic biomarker and a therapeutic target for UCEC.展开更多
A new coordination polymer [Mn{5-（NO2）sal}2（phen）]n （5-（NO2）sal = 5-nitrosalicylate, phen = 1,10-phenanthroline） was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR and X-ray...A new coordination polymer [Mn{5-（NO2）sal}2（phen）]n （5-（NO2）sal = 5-nitrosalicylate, phen = 1,10-phenanthroline） was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The title complex crystallizes in orthorhombic, space group Pbcn with α = 25.747（8）, b = 13.220（4）, c = 7.009（3） A, V= 2386（1）A^3, Z = 4, R = 0.0427 and wR = 0.0890. The 5-nitrosalicylate anions doubly bridge the Mn（Ⅱ） atoms to form a one-dimensional polymeric chain with repeated eight-membered ring units （Mn-O-C-O）2. The crystal structure is stabilized by intra- and interchain hydrogen bonding interactions. The cyclic voltammetric behavior of the title complex is also reported.展开更多
Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this ...Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this work,a one‐step hydrothermal method was used to manipulate the bimetallic ion intercalation into the interlayer of vanadium oxide.The pre‐intercalated Cu ions act as pillars to pin the vanadium oxide(V‐O)layers,establishing stabilized two‐dimensional channels for fast Zn^(2+) diffusion.The occupation of Mn ions between V‐O interlayer further expands the layer spacing and increases the concentration of oxygen defects(Od),which boosts the Zn^(2+) diffusion kinetics.As a result,as‐prepared Cu_(0.17)Mn_(0.03)V_(2)O_(5−□)·2.16H_(2)O cathode shows outstanding Zn‐storage capabilities under room‐and lowtemperature environments(e.g.,440.3 mAh g^(−1) at room temperature and 294.3 mAh g^(−1)at−60°C).Importantly,it shows a long cycling life and high capacity retention of 93.4%over 2500 cycles at 2 A g^(−1) at−60°C.Furthermore,the reversible intercalation chemistry mechanisms during discharging/charging processes were revealed via operando X‐ray powder diffraction and ex situ Raman characterizations.The strategy of a couple of 3d transition metal doping provides a solution for the development of superior room‐/lowtemperature vanadium‐based cathode materials.展开更多
A novel polymeric zinc（II） complex {[Zn2（TIA）（H2O）3]·（NO3）}n（1, H3TIA = 5-（1H-tetrazol-5-yl）isophthalic acid） has been synthesized in mixed solvents under solvothermal conditions and characterized by ...A novel polymeric zinc（II） complex {[Zn2（TIA）（H2O）3]·（NO3）}n（1, H3TIA = 5-（1H-tetrazol-5-yl）isophthalic acid） has been synthesized in mixed solvents under solvothermal conditions and characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Complex 1 crystallizes in orthorhombic, space group Cmcm with a = 10.4210（6）, b =23.3526（14）, c = 6.9214（4）A, V = 1684.37（17）A^3, Z = 4, C9H4N5O（10）Zn2, Mr = 472.91, Dc = 1.865g/cm^3, F（000） = 932, λ（MoK α） = 2.909 mm^-1, R = 0.0423 and wR = 0.1287. The complex has good thermal stability and excellent photoluminescent property.展开更多
Aqueous rechargeable zinc batteries are getting increasing attention for large-scale energy storage owing to their advantages in terms of cost,environmental friendliness and safety.Here,the layered puckeredγ’-V_(2)O...Aqueous rechargeable zinc batteries are getting increasing attention for large-scale energy storage owing to their advantages in terms of cost,environmental friendliness and safety.Here,the layered puckeredγ’-V_(2)O_(5) polymorph with a porous morphology is firstly introduced as cathode for an aqueous zinc battery system in a binary Zn^(2+)/Li^(+)electrolyte.The Zn‖γ’-V_(2)O_(5) cell delivers high capacities of 240 and190 mAh g^(-1) at current densities of 29 and 147 mA g^(-1),respectively,and remarkable cycling stability in the 1.6 V-0.7 V voltage window(97%retention after 100 cycles at 0.15 A g^(-1)).The detailed structural evolution during first discharge-charge and subsequent cycling is investigated using X-ray diffraction and Raman spectroscopy.We demonstrate a reaction mechanism based on a selective Li insertion in the1.6 V-1.0 V voltage range.It involves a reversible exchange of 0.8 Li^(+)in γ’-V_(2)O_(5) and the same structural response as the one reported in lithiated organic electrolyte.However,in the extended 1.6 V-0.7 V voltage range,this work puts forward a concomitant and gradual phase transformation from γ’-V_(2)O_(5) to zinc pyrovanadate Zn_(3)V_(2)O_(7)(OH)2.2 H_(2)O(ZVO)during cycling.Such mechanism involving the in-situ formation of ZVO,known as an efficient Zn and Li intercalation material,explains the high electrochemical performance here reported for the Zn‖γ’-V_(2)O_(5) cell.This work highlights the peculiar layered-puckeredγ’-V_(2)O_(5) polymorph outperforms the conventionalα-V_(2)O_(5) with a huge improvement of capacity of 240 mAh g^(-1)vs 80 mAh g^(-1) in the same electrolyte and voltage window.展开更多
Zinc chloride is an efficient and safe catalyst in the [3 ＋ 2] cycloaddition reaction of organic nitriles with sodium azide in solventless condition. The corresponding 5-substituted ^1H tetrazoles were obtained under...Zinc chloride is an efficient and safe catalyst in the [3 ＋ 2] cycloaddition reaction of organic nitriles with sodium azide in solventless condition. The corresponding 5-substituted ^1H tetrazoles were obtained under mild conditions. This method can overcome disadvantages such as： the use of toxic metals and expensive reagents, drastic reaction conditions, water sensitivity and the presence of dangerous hydrazoic acid.展开更多
The title compound (C10H12N2O7, Mr = 272.22) crystallizes in triclinic, space group P1 with a = 5.532(2), b = 9.760(4), c = 11.731(5) ?, α = 68.107(7), β = 89.179(7), γ = 77.830(7)o, V = 573.1(4) ?3, Z = 2, Dc = 1....The title compound (C10H12N2O7, Mr = 272.22) crystallizes in triclinic, space group P1 with a = 5.532(2), b = 9.760(4), c = 11.731(5) ?, α = 68.107(7), β = 89.179(7), γ = 77.830(7)o, V = 573.1(4) ?3, Z = 2, Dc = 1.578 g/cm3, F(000) = 284 and μ(MoKa) = 0.136 mm-1. The final R = 0.0400 and wR = 0.0951 for 1468 observed reflections with I > 2σ(I). The title compound is a 1:1 adduct of sarcosine and 5-nitrosalicylic acid. The nitrogen atom of sarcosine is protonated, and the proton is from the carboxyl group of sarcosine and 5-nitrosalicylic acid with the probability of 50 percent for each. The 5-nitrosalicylic acid and sarcosine molecule of the title adduct are ABAB arranged along the c axis. There exist a lot of hydrogen bonds in the structure, linking sarcosine and 5-nitrosalicylic acid to form a three-dimensional network.展开更多
The title adduct (C18H24N4O12, Mr = 488.41) crystallizes in monoclinic, space group P21/c with a = 4.0514(19), b = 25.193(11), c = 10.751(5) ?, β = 95.070(8)o, V = 1093.0(9) ?3, Z = 4, Dc = 1.484 g/cm3, F(000) = 51...The title adduct (C18H24N4O12, Mr = 488.41) crystallizes in monoclinic, space group P21/c with a = 4.0514(19), b = 25.193(11), c = 10.751(5) ?, β = 95.070(8)o, V = 1093.0(9) ?3, Z = 4, Dc = 1.484 g/cm3, F(000) = 512, μ(MoKα) = 1.26 cm-1, T = 293 K, the final R = 0.0593 and wR = 0.0862 for 956 observed reflections with I > 2σ(I). The compound is a 1:1 adduct of ethanolamine and 5-nitrosalicylic acid. The nitrogen atom of ethanolamine is protonated. In this crystal there exist a number of hydrogen bonds which link the ethanolamine and 5-nitrosalicylic acid molecules to form a three-dimensional infinite network structure.展开更多
A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hyd...A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.展开更多
锌-空气电池(ZAB)因其能量密度高、环境友好、成本低以及安全性高而备受关注.然而,空气电极上的氧还原反应(ORR)动力学缓慢,严重限制了ZAB的输出功率.尽管铂基催化剂展现出优异的ORR催化活性,但高昂的成本制约其大规模商业化应用.因此,...锌-空气电池(ZAB)因其能量密度高、环境友好、成本低以及安全性高而备受关注.然而,空气电极上的氧还原反应(ORR)动力学缓慢,严重限制了ZAB的输出功率.尽管铂基催化剂展现出优异的ORR催化活性,但高昂的成本制约其大规模商业化应用.因此,迫切需要开发高效、低成本的ORR电催化剂.研究表明,具有原子分散Co-N4活性位点的Co-N-C单原子催化剂是理想的ORR非贵金属催化剂,但其仍然存在与反应关键中间体结合能较高的难题.目前的研究主要通过调控单原子配位环境与增大活性位点密度来提高Co-N-C催化剂的活性,但如何精确控制中心金属电子结构以及避免高温下金属原子的团聚仍面临巨大挑战.除了单原子活性位点外,催化剂载体的键合结构、电荷分布状态亦会影响载体本身和单原子位点的催化活性.然而,现有的研究主要聚焦于单原子位点或无金属催化剂单方面活性的提升,关于它们之间的相互作用对于催化性能影响的研究相对很少.为了进一步提高Co单原子催化剂的催化活性,本文通过简单的模板法与NH3二次处理策略制备了氮掺杂缺陷碳负载的Co-N_(5)位点单原子催化剂.电感耦合等离子体发射光谱结果表明,单原子Co的金属负载量高达2.57 wt%.此外,相比于未经过NH3二次处理的Co-Nx/HC样品,Co-N_(5)/DHC样品在电子顺磁共振谱中g=2.003处呈现出更明显的共振信号,在C 1s高分辨谱中具有更低的C-C(sp2杂化)/C-N(sp3杂化)比例以及明显增加的吡啶氮信号,证实了Co-N_(5)/DHC显著提升的氮掺杂碳缺陷浓度并具有丰富的边界/缺陷位点.同时,X射线吸收谱与球差矫正透射电子显微镜结果表明所制备的样品为原子分散的Co-N_(5)结构,从而证明成功制备了缺陷氮掺杂碳耦合Co-N_(5)位点单原子催化剂.电化学测试结果表明,缺陷氮掺杂碳耦合Co-N_(5)位点后表现较好的ORR性能,半波电位达到0.877 V,明显高于Co-Nx/HC对比样品和商业化Pt/C催化剂.Koutecky-Levich曲线和旋转盘环电极测试结果表明,Co-N_(5)/DHC催化剂的高效4e-反应路径.且在10000次的加速老化测试中,Co-N_(5)/DHC半波电位仅降低了7 m V,稳定性优于Pt/C.以Co-N_(5)/DHC为阴极催化剂组装的ZAB开路电压为1.45 V,峰值输出功率密度能够达到160.7 m W cm^(-2),并能提供766.2 m A h gZn-1的比容量,展现出较高的应用前景.密度泛函理论计算表明,Co-N_(5)位点与缺陷氮掺杂碳的相互作用诱导Co中心位点电子的重新分布,降低了ORR反应能垒.综上,本文为设计与合成高性能的Co单原子催化剂,用于先进的可再生能源转换系统提供了一种新思路.展开更多
基金supported by the Science-Technology Foundation for Middle-aged and Young Scientists of Wannan Medical College(No.WK2021F19)the 2023 Wannan Medical College Research Fund(No.WK2023ZZD18).
文摘Objective:Uterine corpus endometrial carcinoma(UCEC),a kind of gynecologic malignancy,poses a significant risk to women’s health.The precise mechanism underlying the development of UCEC remains elusive.Zinc finger protein 554(ZNF554),a member of the Krüppel-associated box domain zinc finger protein superfamily,was reported to be dysregulated in various illnesses,including malignant tumors.This study aimed to examine the involvement of ZNF554 in the development of UCEC.Methods:The expression of ZNF554 in UCEC tissues and cell lines were examined by qRT-PCR and Western blot assay.Cells with stably overexpressed or knocked-down ZNF554 were established through lentivirus infection.CCK-8,wound healing,and Transwell invasion assays were employed to assess cell proliferation,migration,and invasion.Propidium iodide(PI)staining combined with fluorescence-activated cell sorting(FACS)flow cytometer was utilized to detect cell cycle distribution.qRT-PCR and Western blotting were conducted to examine relative mRNA and protein levels.Chromatin immunoprecipitation assay and luciferase reporter assay were used to explore the regulatory role of ZNF554 in RNA binding motif 5(RBM5).Results:The expression of ZNF554 was found to be reduced in both UCEC samples and cell lines.Decreased expression of ZNF554 was associated with higher tumor stage,decreased overall survival,and reduced disease-free survival in UCEC.ZNF554 overexpression suppressed cell proliferation,migration,and invasion,while also inducing cell cycle arrest.In contrast,a decrease in ZNF554 expression resulted in the opposite effect.Mechanistically,ZNF554 transcriptionally regulated RBM5,leading to the deactivation of the Wingless(WNT)/β-catenin signaling pathway.Moreover,the findings from rescue studies demonstrated that the inhibition of RBM5 negated the impact of ZNF554 overexpression onβ-catenin and p-glycogen synthase kinase-3β(p-GSK-3β).Similarly,the deliberate activation of RBM5 reduced the increase inβ-catenin and p-GSK-3βcaused by the suppression of ZNF554.In vitro experiments showed that ZNF554 overexpression-induced decreases in cell proliferation and migration were counteracted by RBM5 knockdown.Additionally,when RBM5 was overexpressed,it hindered the improvements in cell proliferation and migration caused by reducing the ZNF554 levels.Conclusion:ZNF554 functions as a tumor suppressor in UCEC.Furthermore,ZNF554 regulates UCEC progression through the RBM5/WNT/β-catenin signaling pathway.ZNF554 shows a promise as both a prognostic biomarker and a therapeutic target for UCEC.
基金supported by the Education Department of Fujian Province (No. JA02261)
文摘A new coordination polymer [Mn{5-（NO2）sal}2（phen）]n （5-（NO2）sal = 5-nitrosalicylate, phen = 1,10-phenanthroline） was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR and X-ray single-crystal diffraction. The title complex crystallizes in orthorhombic, space group Pbcn with α = 25.747（8）, b = 13.220（4）, c = 7.009（3） A, V= 2386（1）A^3, Z = 4, R = 0.0427 and wR = 0.0890. The 5-nitrosalicylate anions doubly bridge the Mn（Ⅱ） atoms to form a one-dimensional polymeric chain with repeated eight-membered ring units （Mn-O-C-O）2. The crystal structure is stabilized by intra- and interchain hydrogen bonding interactions. The cyclic voltammetric behavior of the title complex is also reported.
基金National Natural Science Foundation of China,Grant/Award Numbers:52372188,51902090,51922008,520721142023 Introduction of studying abroad talent program,the China Postdoctoral Science Foundation,Grant/Award Number:2019 M652546+3 种基金Xinxiang Major Science and Technology Projects,Grant/Award Number:21ZD001Henan Province Postdoctoral Start‐Up Foundation,Grant/Award Number:1901017Henan Center for Outstanding Overseas Scientists,Grant/Award Number:GZS2018003Overseas Expertise Introduction Project for Discipline Innovation,Grant/Award Number:D17007。
文摘Vanadium oxide cathode materials with stable crystal structure and fast Zn^(2+) storage capabilities are extremely important to achieving outstanding electrochemical performance in aqueous zinc‐ion batteries.In this work,a one‐step hydrothermal method was used to manipulate the bimetallic ion intercalation into the interlayer of vanadium oxide.The pre‐intercalated Cu ions act as pillars to pin the vanadium oxide(V‐O)layers,establishing stabilized two‐dimensional channels for fast Zn^(2+) diffusion.The occupation of Mn ions between V‐O interlayer further expands the layer spacing and increases the concentration of oxygen defects(Od),which boosts the Zn^(2+) diffusion kinetics.As a result,as‐prepared Cu_(0.17)Mn_(0.03)V_(2)O_(5−□)·2.16H_(2)O cathode shows outstanding Zn‐storage capabilities under room‐and lowtemperature environments(e.g.,440.3 mAh g^(−1) at room temperature and 294.3 mAh g^(−1)at−60°C).Importantly,it shows a long cycling life and high capacity retention of 93.4%over 2500 cycles at 2 A g^(−1) at−60°C.Furthermore,the reversible intercalation chemistry mechanisms during discharging/charging processes were revealed via operando X‐ray powder diffraction and ex situ Raman characterizations.The strategy of a couple of 3d transition metal doping provides a solution for the development of superior room‐/lowtemperature vanadium‐based cathode materials.
基金Supported by the National Natural Science Foundation of China(No.21576112)the Program for New Century Excellent Talents in University(NCET-10-0176)of ChinaNatural Science Foundation Project of Jilin Province(No.20130521019JH and 201215219)
文摘A novel polymeric zinc（II） complex {[Zn2（TIA）（H2O）3]·（NO3）}n（1, H3TIA = 5-（1H-tetrazol-5-yl）isophthalic acid） has been synthesized in mixed solvents under solvothermal conditions and characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Complex 1 crystallizes in orthorhombic, space group Cmcm with a = 10.4210（6）, b =23.3526（14）, c = 6.9214（4）A, V = 1684.37（17）A^3, Z = 4, C9H4N5O（10）Zn2, Mr = 472.91, Dc = 1.865g/cm^3, F（000） = 932, λ（MoK α） = 2.909 mm^-1, R = 0.0423 and wR = 0.1287. The complex has good thermal stability and excellent photoluminescent property.
基金the Ministry of Education and Science of Kazakhstan(grant number AP05136016-ZRABS)French Embassy in Astana,Kazakhstan and Campus France for financial support。
文摘Aqueous rechargeable zinc batteries are getting increasing attention for large-scale energy storage owing to their advantages in terms of cost,environmental friendliness and safety.Here,the layered puckeredγ’-V_(2)O_(5) polymorph with a porous morphology is firstly introduced as cathode for an aqueous zinc battery system in a binary Zn^(2+)/Li^(+)electrolyte.The Zn‖γ’-V_(2)O_(5) cell delivers high capacities of 240 and190 mAh g^(-1) at current densities of 29 and 147 mA g^(-1),respectively,and remarkable cycling stability in the 1.6 V-0.7 V voltage window(97%retention after 100 cycles at 0.15 A g^(-1)).The detailed structural evolution during first discharge-charge and subsequent cycling is investigated using X-ray diffraction and Raman spectroscopy.We demonstrate a reaction mechanism based on a selective Li insertion in the1.6 V-1.0 V voltage range.It involves a reversible exchange of 0.8 Li^(+)in γ’-V_(2)O_(5) and the same structural response as the one reported in lithiated organic electrolyte.However,in the extended 1.6 V-0.7 V voltage range,this work puts forward a concomitant and gradual phase transformation from γ’-V_(2)O_(5) to zinc pyrovanadate Zn_(3)V_(2)O_(7)(OH)2.2 H_(2)O(ZVO)during cycling.Such mechanism involving the in-situ formation of ZVO,known as an efficient Zn and Li intercalation material,explains the high electrochemical performance here reported for the Zn‖γ’-V_(2)O_(5) cell.This work highlights the peculiar layered-puckeredγ’-V_(2)O_(5) polymorph outperforms the conventionalα-V_(2)O_(5) with a huge improvement of capacity of 240 mAh g^(-1)vs 80 mAh g^(-1) in the same electrolyte and voltage window.
基金Research Council of K.N.Toosi University of Technology for partial financial support of this work
文摘Zinc chloride is an efficient and safe catalyst in the [3 ＋ 2] cycloaddition reaction of organic nitriles with sodium azide in solventless condition. The corresponding 5-substituted ^1H tetrazoles were obtained under mild conditions. This method can overcome disadvantages such as： the use of toxic metals and expensive reagents, drastic reaction conditions, water sensitivity and the presence of dangerous hydrazoic acid.
文摘The title compound (C10H12N2O7, Mr = 272.22) crystallizes in triclinic, space group P1 with a = 5.532(2), b = 9.760(4), c = 11.731(5) ?, α = 68.107(7), β = 89.179(7), γ = 77.830(7)o, V = 573.1(4) ?3, Z = 2, Dc = 1.578 g/cm3, F(000) = 284 and μ(MoKa) = 0.136 mm-1. The final R = 0.0400 and wR = 0.0951 for 1468 observed reflections with I > 2σ(I). The title compound is a 1:1 adduct of sarcosine and 5-nitrosalicylic acid. The nitrogen atom of sarcosine is protonated, and the proton is from the carboxyl group of sarcosine and 5-nitrosalicylic acid with the probability of 50 percent for each. The 5-nitrosalicylic acid and sarcosine molecule of the title adduct are ABAB arranged along the c axis. There exist a lot of hydrogen bonds in the structure, linking sarcosine and 5-nitrosalicylic acid to form a three-dimensional network.
文摘The title adduct (C18H24N4O12, Mr = 488.41) crystallizes in monoclinic, space group P21/c with a = 4.0514(19), b = 25.193(11), c = 10.751(5) ?, β = 95.070(8)o, V = 1093.0(9) ?3, Z = 4, Dc = 1.484 g/cm3, F(000) = 512, μ(MoKα) = 1.26 cm-1, T = 293 K, the final R = 0.0593 and wR = 0.0862 for 956 observed reflections with I > 2σ(I). The compound is a 1:1 adduct of ethanolamine and 5-nitrosalicylic acid. The nitrogen atom of ethanolamine is protonated. In this crystal there exist a number of hydrogen bonds which link the ethanolamine and 5-nitrosalicylic acid molecules to form a three-dimensional infinite network structure.
基金The authors thank the National Natural ScienceFoundation of China (NNSFC)! (No. 29872051 and No. 29672041 )for financial support
文摘A one pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pryane with alkyl bromide RBr in the presence of zinc powder gave corresponding alcohol (CH2)3OCH=C(R)C(CF3)OH (R:CH2=CHCH2-, 3a; CH2CO2Me 3b), 3b are readily hydrolysed to corresponding carboxylic acid under dilute acidic condition, intramolecular cycle addition of this acid afforded bicyclo lactone. Treatment of 5 with pyridine and POCl3 to afford product dehydroration by the trifluoromethyl substituted α,β-unsaturated carbonyl compound 6.4- Trifluoroacetyl 2,3-dihydro-2H-furan behaves similar compounds 8, 9 and 10 are prepared.
文摘锌-空气电池(ZAB)因其能量密度高、环境友好、成本低以及安全性高而备受关注.然而,空气电极上的氧还原反应(ORR)动力学缓慢,严重限制了ZAB的输出功率.尽管铂基催化剂展现出优异的ORR催化活性,但高昂的成本制约其大规模商业化应用.因此,迫切需要开发高效、低成本的ORR电催化剂.研究表明,具有原子分散Co-N4活性位点的Co-N-C单原子催化剂是理想的ORR非贵金属催化剂,但其仍然存在与反应关键中间体结合能较高的难题.目前的研究主要通过调控单原子配位环境与增大活性位点密度来提高Co-N-C催化剂的活性,但如何精确控制中心金属电子结构以及避免高温下金属原子的团聚仍面临巨大挑战.除了单原子活性位点外,催化剂载体的键合结构、电荷分布状态亦会影响载体本身和单原子位点的催化活性.然而,现有的研究主要聚焦于单原子位点或无金属催化剂单方面活性的提升,关于它们之间的相互作用对于催化性能影响的研究相对很少.为了进一步提高Co单原子催化剂的催化活性,本文通过简单的模板法与NH3二次处理策略制备了氮掺杂缺陷碳负载的Co-N_(5)位点单原子催化剂.电感耦合等离子体发射光谱结果表明,单原子Co的金属负载量高达2.57 wt%.此外,相比于未经过NH3二次处理的Co-Nx/HC样品,Co-N_(5)/DHC样品在电子顺磁共振谱中g=2.003处呈现出更明显的共振信号,在C 1s高分辨谱中具有更低的C-C(sp2杂化)/C-N(sp3杂化)比例以及明显增加的吡啶氮信号,证实了Co-N_(5)/DHC显著提升的氮掺杂碳缺陷浓度并具有丰富的边界/缺陷位点.同时,X射线吸收谱与球差矫正透射电子显微镜结果表明所制备的样品为原子分散的Co-N_(5)结构,从而证明成功制备了缺陷氮掺杂碳耦合Co-N_(5)位点单原子催化剂.电化学测试结果表明,缺陷氮掺杂碳耦合Co-N_(5)位点后表现较好的ORR性能,半波电位达到0.877 V,明显高于Co-Nx/HC对比样品和商业化Pt/C催化剂.Koutecky-Levich曲线和旋转盘环电极测试结果表明,Co-N_(5)/DHC催化剂的高效4e-反应路径.且在10000次的加速老化测试中,Co-N_(5)/DHC半波电位仅降低了7 m V,稳定性优于Pt/C.以Co-N_(5)/DHC为阴极催化剂组装的ZAB开路电压为1.45 V,峰值输出功率密度能够达到160.7 m W cm^(-2),并能提供766.2 m A h gZn-1的比容量,展现出较高的应用前景.密度泛函理论计算表明,Co-N_(5)位点与缺陷氮掺杂碳的相互作用诱导Co中心位点电子的重新分布,降低了ORR反应能垒.综上,本文为设计与合成高性能的Co单原子催化剂,用于先进的可再生能源转换系统提供了一种新思路.
