Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various ...Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various types of hazardous elements are required. Among such impurities, hexavalent chromium (Cr(VI)) is very likely to become a future challenge. Different industrial ways to treat phosphate rock are currently being practised, and we have here studied how chromium behaves when using the nitro-phosphate process. The reduction mechanism of Cr (VI) in nitric acid and phosphoric acid solutions was investigated by measuring redox potential and UV-VIS spectra. The results show that Cr (VI) is not stable in strong nitric acid solutions. Reduction of Cr (VI) species decreased with decreasing temperature, NO<sub>2</sub> concentration, ionic strength and absence of light. These findings support the proposed reduction reaction:The reduction rate was observed proportional to the nitric acid decomposition: .展开更多
Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a no...Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a novel negative electrode with superior electrocatalytic activity by tailoring nitrogen functional groups,such as newly formed nitro and pyridinic-N transformed to pyridonic-N,from the prenitrogen-doped electrode.It was experimentally confirmed that an electrode with pyridonic-N and nitro fuctional groups(tailored nitrogen-doped graphite felt,TNGF) has superior electrocatalytic acivity with enhanced electron and mass transfer.Density functional theory calulations demonstrated the pyridonic-N and nitro functional groups promoted the adsorption,charge transfer,and bond formation with the vanadium species,which is consistent with expermental results.In addition,the V2+/V3+redox reaction mechanism on pyridonic-N and nitro functional groups was estabilised based on density functional theory(DFT) results.When TNGF was applied to a VRFB,it enabled enhanced-electrolyte utilization and energy efficiencies(EE) of 57.9% and 64.6%,respectively,at a current density of 250 mA cm^(-2).These results are 18.6% and 8.9% higher than those of VRFB with electrode containing graphitic-N and pyridinicN groups.Interestingly,TNGF-based VRFB still operated with an EE of 59% at a high current density of300 mA cm^(-2).The TNGF-based VRFB exhibited stable cycling performance without noticeable decay of EE over 450 charge-discharge cycles at a current density of 250 mA cm^(-2).The results of this study suggest that introducing pyridonic-N and nitro groups on the electrode is effective for improving the electrochemical performance of VRFBs.展开更多
Nitroalkanes react smoothly with CF3CCl2COCH=CHPh via Michael addition in the presence of inorganic bases such as KF/Al2O3 or K2CO3, giving fluorinecontaining γ-nitro ketones in good yields.
Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,...Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,with the water content higher than 50%,the K-bands of N<sub>4</sub>.N,N<sub>6</sub> and N<sub>10</sub>in the UV absorption spectra shifted to longer wavelengths as comparedwth 4-nitrophenoxyethane（N<sub>0</sub>）.It is suggested that in poor solvents the two aromaticgrps are close to each other in parallel,forming ground state complexes.The K-bead of N<sub>4</sub> showed a blue shift from that of N<sub>0</sub> when the water content was around5%,probably attributable to a conformation with the nitro group of one benzene ringsiting on the plane of the other benzene ring.展开更多
N-Acetyl-P. m or o-nitro-phenylethylamines and (HCHO). were treated in 60% H,SO./HOAc. via α -amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-l .2,3.4- tetrahydroisoquinolines. Additionally. solme interesti...N-Acetyl-P. m or o-nitro-phenylethylamines and (HCHO). were treated in 60% H,SO./HOAc. via α -amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-l .2,3.4- tetrahydroisoquinolines. Additionally. solme interesting phenomena were observed when the comparison between 2-acetyl-5, 6. 7 or 8-nitro-l,2.3.4-tetrahydroisoqui and 2-alkylsulfonyl-5. 6 or 7nitro-l,2.3,4-tetrahydroisoquinolines was made.展开更多
Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free co...Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.展开更多
Dinitropyrenes (DNP) were prepared by nitration of pyrene, and the product was characterized by MS and elemental analysis. Three isomers of DNP were separated by HPLC and identified by 1H-NMR. The eating sequence on t...Dinitropyrenes (DNP) were prepared by nitration of pyrene, and the product was characterized by MS and elemental analysis. Three isomers of DNP were separated by HPLC and identified by 1H-NMR. The eating sequence on the normal phase column is 1, 3-DNP, 1, 6-DNP and 1, 8-DNP, whereas is 1, 6-DNP, 1. 8-DNP and 1. 3-DNP on the reversed phase column. The separation of three DNP isomers under different chromatographic conditions was also discussed.展开更多
UHF-SCF-AM1 MO calculations were performed for two kinds of pyrolysis reactions of seven nitro derivatives of methylbenzene（homolysis reactions by the rupture of bond C-NO2 into radicals and isomerization reactions i...UHF-SCF-AM1 MO calculations were performed for two kinds of pyrolysis reactions of seven nitro derivatives of methylbenzene（homolysis reactions by the rupture of bond C-NO2 into radicals and isomerization reactions in the way of methyl H transferring to the ortho nitro O atom）. The molecular geometries of the reactants, the transition states and the products of the fourteen reactions were fully optimized. The activation energies for these two kinds of reactions have been obtained. The results indicate that this category of compounds is more easily pyrolyzed by being initiated via isomerization reactions. A parallel relationship exists between the activation energy of the isomerization reactions and the impact sensitivity of the seven titled compounds.展开更多
A novel hasubanan alkaloid has been isolated along with the known aknadinine from thefresh roots of Stephania sutchenensis.Its structure has been established as 1—nitroaknadinine from detailedspectral studies and con...A novel hasubanan alkaloid has been isolated along with the known aknadinine from thefresh roots of Stephania sutchenensis.Its structure has been established as 1—nitroaknadinine from detailedspectral studies and confirmed by chemical correlation with aknadinine.The novel alkaloid is the firstnitro-hasubanan and also the first example of naturally occurring nitro—alkaloids.展开更多
Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI<sub>2</sub>O<sub>3</sub>/PEG4000 without solvent.Yields are fair to good and work-ups ar...Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI<sub>2</sub>O<sub>3</sub>/PEG4000 without solvent.Yields are fair to good and work-ups are easy.展开更多
文摘Phosphorus fertilizers from less pure sedimentary sources become increasingly important, due to depletion of phosphorus from igneous rock of high quality. Consequently, robust methods with potential to remove various types of hazardous elements are required. Among such impurities, hexavalent chromium (Cr(VI)) is very likely to become a future challenge. Different industrial ways to treat phosphate rock are currently being practised, and we have here studied how chromium behaves when using the nitro-phosphate process. The reduction mechanism of Cr (VI) in nitric acid and phosphoric acid solutions was investigated by measuring redox potential and UV-VIS spectra. The results show that Cr (VI) is not stable in strong nitric acid solutions. Reduction of Cr (VI) species decreased with decreasing temperature, NO<sub>2</sub> concentration, ionic strength and absence of light. These findings support the proposed reduction reaction:The reduction rate was observed proportional to the nitric acid decomposition: .
基金financially supported by the Research Program from Korea Institute of Industrial Technology(EM220011)the Technology Innovation Program(20020229,Development of technology for manufacturing catalysts and electrode parts by use of low contents precious metals of rare metals) funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)+2 种基金the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(2022R1F1A1072569)supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Science,ICT & Future Planning(NRF2020R1C1C1010493)“Regional Innovation Strategy(RIS)” through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(MOE)(2021RIS-004)。
文摘Development of electrodes with high electrocatalytic activity and stability is essential for solving problems that still restrict the extensive application of vanadium redox flow batteries(VRFBs).Here,we designed a novel negative electrode with superior electrocatalytic activity by tailoring nitrogen functional groups,such as newly formed nitro and pyridinic-N transformed to pyridonic-N,from the prenitrogen-doped electrode.It was experimentally confirmed that an electrode with pyridonic-N and nitro fuctional groups(tailored nitrogen-doped graphite felt,TNGF) has superior electrocatalytic acivity with enhanced electron and mass transfer.Density functional theory calulations demonstrated the pyridonic-N and nitro functional groups promoted the adsorption,charge transfer,and bond formation with the vanadium species,which is consistent with expermental results.In addition,the V2+/V3+redox reaction mechanism on pyridonic-N and nitro functional groups was estabilised based on density functional theory(DFT) results.When TNGF was applied to a VRFB,it enabled enhanced-electrolyte utilization and energy efficiencies(EE) of 57.9% and 64.6%,respectively,at a current density of 250 mA cm^(-2).These results are 18.6% and 8.9% higher than those of VRFB with electrode containing graphitic-N and pyridinicN groups.Interestingly,TNGF-based VRFB still operated with an EE of 59% at a high current density of300 mA cm^(-2).The TNGF-based VRFB exhibited stable cycling performance without noticeable decay of EE over 450 charge-discharge cycles at a current density of 250 mA cm^(-2).The results of this study suggest that introducing pyridonic-N and nitro groups on the electrode is effective for improving the electrochemical performance of VRFBs.
文摘Nitroalkanes react smoothly with CF3CCl2COCH=CHPh via Michael addition in the presence of inorganic bases such as KF/Al2O3 or K2CO3, giving fluorinecontaining γ-nitro ketones in good yields.
文摘Solvent effect on the conformations of-bis（4-nitrophenoxy）-alkanesw th different chain Lengths（Nn）was studied by UV spectra.In poor solvents such asEG-H<sub>2</sub>O and THF-H<sub>2</sub>O,with the water content higher than 50%,the K-bands of N<sub>4</sub>.N,N<sub>6</sub> and N<sub>10</sub>in the UV absorption spectra shifted to longer wavelengths as comparedwth 4-nitrophenoxyethane（N<sub>0</sub>）.It is suggested that in poor solvents the two aromaticgrps are close to each other in parallel,forming ground state complexes.The K-bead of N<sub>4</sub> showed a blue shift from that of N<sub>0</sub> when the water content was around5%,probably attributable to a conformation with the nitro group of one benzene ringsiting on the plane of the other benzene ring.
基金the new drug discovery foundation of Shanghai instituteof Pharmaceutical Industry and the Analysis Centre of the Second Milita
文摘N-Acetyl-P. m or o-nitro-phenylethylamines and (HCHO). were treated in 60% H,SO./HOAc. via α -amidoalkylation to give 2-acetyl-mono(5, 6, 7 or 8)-nitro-l .2,3.4- tetrahydroisoquinolines. Additionally. solme interesting phenomena were observed when the comparison between 2-acetyl-5, 6. 7 or 8-nitro-l,2.3.4-tetrahydroisoqui and 2-alkylsulfonyl-5. 6 or 7nitro-l,2.3,4-tetrahydroisoquinolines was made.
文摘Poly ethylene glycols (PEG-200, 400, 600, 4000 and 6000) supported reactions were conducted with certain α, β-unsaturated acids in presence of metal nitrates under solvent free (solid state) and mineral acid free conditions. The reactants were ground in a mortar with a pestle for about 30 minutes. The aromatic acids underwent nitro decarboxylation and afforded β-nitro styrene derivatives in very good yield while α, β-unsaturated aliphatic carboxylic acids gave corresponding nitro derivatives. Addition of PEG accelerated rate of the reaction enormously. Reaction times substantially decreased from several hours to few minutes followed by highly significant increase in the product yield. Among the several PEGs PEG-300 has been found to be much more effective than other PEGs.
文摘Dinitropyrenes (DNP) were prepared by nitration of pyrene, and the product was characterized by MS and elemental analysis. Three isomers of DNP were separated by HPLC and identified by 1H-NMR. The eating sequence on the normal phase column is 1, 3-DNP, 1, 6-DNP and 1, 8-DNP, whereas is 1, 6-DNP, 1. 8-DNP and 1. 3-DNP on the reversed phase column. The separation of three DNP isomers under different chromatographic conditions was also discussed.
文摘UHF-SCF-AM1 MO calculations were performed for two kinds of pyrolysis reactions of seven nitro derivatives of methylbenzene（homolysis reactions by the rupture of bond C-NO2 into radicals and isomerization reactions in the way of methyl H transferring to the ortho nitro O atom）. The molecular geometries of the reactants, the transition states and the products of the fourteen reactions were fully optimized. The activation energies for these two kinds of reactions have been obtained. The results indicate that this category of compounds is more easily pyrolyzed by being initiated via isomerization reactions. A parallel relationship exists between the activation energy of the isomerization reactions and the impact sensitivity of the seven titled compounds.
文摘A novel hasubanan alkaloid has been isolated along with the known aknadinine from thefresh roots of Stephania sutchenensis.Its structure has been established as 1—nitroaknadinine from detailedspectral studies and confirmed by chemical correlation with aknadinine.The novel alkaloid is the firstnitro-hasubanan and also the first example of naturally occurring nitro—alkaloids.
文摘Michael addition of nitroalkanes to α,β-unsaturated carbonyl compounds occurs in the presence of KF/AI<sub>2</sub>O<sub>3</sub>/PEG4000 without solvent.Yields are fair to good and work-ups are easy.
