A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was de...A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.展开更多
Better understanding of electrochemical reaction behaviors of hydrazine electrooxidation at metal phosphides has long been desired and the optimization of reaction kinetics has been proved to be operable.Herein,the de...Better understanding of electrochemical reaction behaviors of hydrazine electrooxidation at metal phosphides has long been desired and the optimization of reaction kinetics has been proved to be operable.Herein,the dehydrogenation kinetics of hydrazine electrooxidation at Ni_(2)P is adjusted by Co as the(Ni_(0.6)Co_(0.4))_(2)P catalyzes HzOR effectively with onset potential of–45 mV and only 113 mV is needed to drive the current density of 50 mA cm^(‒2),showing over 60 mV lower than Ni_(2)P and Co_(2)P.It also delivers the maximum power density of 263.0 mW cm^(-2) for direct hydrazine fuel cell.Detailed experimental results revealed that Co doping not only decreases the adsorption energy of N_(2)H_(4) on Ni sites,lowering the energy barrier for dehydrogenation,but also acts as the active sites in the optimal reaction coordination to boost the reaction kinetics.This work represents a breakthrough in improving the catalytic performance of non‐precious metal electrocatalysts for hydrazine electrooxidation and highlights an energy‐saving electrochemical hydrogen production method.展开更多
A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste ele...A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.展开更多
The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazid...The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazide derivatives is reported. The method involves the preparation ofper-O-acetylated glycosyl isothiocyanates from per-O-acetylated sugars （two-step synthesis）, which couple with heterocyclic hydrazides from amines to give thiourea-linked pseudonucleosides. All newly synthesized pseudo-nucleosides were assayed against human lung cancer-cell lines （PG） and human liver cancer-cell lines （BEL-7402） in vitro. The 6,6-dimethyl-benzothiophen-3-carbo-hydrazide-4-one pseudonucleosides showed moderate inhibition against these two cancer-cell lines with ECs0 from 22.8 to 76.4 mM and from 54.9 to 82.4 mM, respectively. And the other compounds did not demonstrate any significant cytotoxicity even at concentrations up to 200 mM.展开更多
The title compound (PhNHNH)2C=OCH3CN has been prepared and characterized by elemental analysis and IR spectrum studies. The single-crystal X-ray structure determination of the title compound was carried out. It crysta...The title compound (PhNHNH)2C=OCH3CN has been prepared and characterized by elemental analysis and IR spectrum studies. The single-crystal X-ray structure determination of the title compound was carried out. It crystallizes in the monoclinic system, space group P21/n with a = 5.7818(2), b = 15.320(1), c = 17.469(1) ? b = 97.476(1)? V = 1534.2(1) 3, Mr = 283.34 (C15H17N5O), Z = 4, Dc = 1.227 g/cm3 , F(000) = 600, ?= 0.082 mm-1, R = 0.0561 and wR = 0.1538. The total reflections were 8214 and the independent ones were 2624 (Rint = 0.0559), of which 1756 were observed with I > 2s(I). The torsion angles of the important groups (C(6)N(1) N(2)C(7) and C(7)N(3)N(4)C(8)) are 68.3(3) and 93.3(3), respectively. In the crystal lattice, the molecules form a network structure through hydrogen bonds. The crystal structure is stabilized by NH…N and NH…O hydrogen bonds. FT-IR spectra clearly show there exist acetonitrile molecules in the crystal lattice.展开更多
Pollution of environment, connected with intensive industry and, as a result, declination of health of nation is one of the biggest problems of modem age. The purpose of research was the studying of influence of hydra...Pollution of environment, connected with intensive industry and, as a result, declination of health of nation is one of the biggest problems of modem age. The purpose of research was the studying of influence of hydrazine derivatives on redistribution of plasma protein between blood and lymph and change of hemodynamic poisoned by 1, l-nitrozodimethylamine. parameter caused by this. There were some changes in organism展开更多
The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Res...The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Results of field tests have shown high efficiency of the catalyst ＂Mukhamedzhan- 1＂ for detoxification UDMH.展开更多
文摘A magnetic bar carbon paste electrode （MBCPE） modified with Fe3O4 magnetic nanoparticles （Fe3O4NPs） and 2‐（3,4‐dihydroxyphenyl） benzothiazole （DPB） for the electrochemical determina‐tion of hydrazine was developed. The DPB was firstly self‐assembled on the Fe3O4NPs, and the re‐sulting Fe3O4NPs/DPB composite was then absorbed on the designed MBCPE. The MBCPE was used to attract the magnetic nanoparticles to the electrode surface. Owing to its high conductivity and large effective surface area, the novel electrode had a very large current response for the electrocat‐alytic oxidation of hydrazine. The modified electrode was characterized by voltammetry, scanning electron microscopy, electrochemical impedance spectroscopy, infrared spectroscopy, and UV‐visible spectroscopy. Voltammetric methods were used to study the electrochemical behaviour of hydrazine on MBCPE/Fe3O4NPs/DPB in phosphate buffer solution （pH = 7.0）. The MBCPE/Fe3O4NPs/DPB, acting as an electrochemical sensor, exhibited very high electrocatalytic activity for the oxidation of hydrazine. The presence of DPB was found to reduce the oxidation potential of hydrazine and increase the catalytic current. The dependence of the electrocatalytic current on the hydrazine concentration exhibited two linear ranges, 0.1–0.4 μmol/L and 0.7–12.0 μmol/L, with a detection limit of 18.0 nmol/L. Additionally, the simultaneous determination of hydrazine and phe‐nol was investigated using the MBCPE/Fe3O4NPs/DPB electrode. Voltammetric experiments showed a linear range of 100–470 μmol/L and a detection limit of 24.3 μmol/L for phenol, and the proposed electrode was applied to the determination of hydrazine and phenol in water samples.
文摘Better understanding of electrochemical reaction behaviors of hydrazine electrooxidation at metal phosphides has long been desired and the optimization of reaction kinetics has been proved to be operable.Herein,the dehydrogenation kinetics of hydrazine electrooxidation at Ni_(2)P is adjusted by Co as the(Ni_(0.6)Co_(0.4))_(2)P catalyzes HzOR effectively with onset potential of–45 mV and only 113 mV is needed to drive the current density of 50 mA cm^(‒2),showing over 60 mV lower than Ni_(2)P and Co_(2)P.It also delivers the maximum power density of 263.0 mW cm^(-2) for direct hydrazine fuel cell.Detailed experimental results revealed that Co doping not only decreases the adsorption energy of N_(2)H_(4) on Ni sites,lowering the energy barrier for dehydrogenation,but also acts as the active sites in the optimal reaction coordination to boost the reaction kinetics.This work represents a breakthrough in improving the catalytic performance of non‐precious metal electrocatalysts for hydrazine electrooxidation and highlights an energy‐saving electrochemical hydrogen production method.
文摘A nickel salen complex was encapsulated in the supercages of nanozeolite NaA,LTA(linde type A)structure,using the flexible ligand method.The electrochemical behavior and electrocatalytic activity of a carbon paste electrode(CPE)modified with Ni(II)‐Salen‐A(Ni(II)‐SalenA/CPE)for hydrazine oxidation in0.1mol/L NaOH solution were investigated by cyclic voltammetry,chronoamperometry,and chronocoulometry.First,organic‐template‐free synthesis of nanozeolite LTA was performed and the obtained material was characterized by various techniques.The average particle size of the LTA crystals was estimated to be56.1and72nm by X‐ray diffraction and particle size analysis,respectively.The electron transfer coefficient was found to be0.64and the catalytic rate constant for oxidation of hydrazine at the redox sites of Ni(II)‐SalenA/CPE was found to be1.03×105cm3/(mol·s).Investigation of the electrocatalytic mechanism suggested that oxidation of hydrazine occurred through reaction with Ni3+(Salen)O(OH)and also direct electrooxidation.The anodic peak currents revealed a linear dependence on the square root of the scan rate,indicating a diffusion‐controlled process,and the diffusion coefficient of hydrazine was found to be1.18×10?7cm2/s.The results indicated that Ni(II)‐SalenA/CPE displays good electrocatalytic activity toward hydrazine oxidation owing to the porous structure of nanozeolite LTA and the Ni(II)‐Salen complex.Finally,the general reaction mechanism for the electrooxidation of hydrazine on Ni(II)‐SalenA/CPE in alkaline solution involves the transfer of four electrons,in which the first electron transfer reaction acts as the rate‐limiting step followed by a three‐electron process to generate environmentally friendly nitrogen and water as final products.
文摘The practical synthesis of pseudonucleosides incorporating thiourea derivative by coupling of monosaccharides （D-glucose and D-galactose） per-O-acetylated glycosyl isothiocyanates and different heterocyclic hydrazide derivatives is reported. The method involves the preparation ofper-O-acetylated glycosyl isothiocyanates from per-O-acetylated sugars （two-step synthesis）, which couple with heterocyclic hydrazides from amines to give thiourea-linked pseudonucleosides. All newly synthesized pseudo-nucleosides were assayed against human lung cancer-cell lines （PG） and human liver cancer-cell lines （BEL-7402） in vitro. The 6,6-dimethyl-benzothiophen-3-carbo-hydrazide-4-one pseudonucleosides showed moderate inhibition against these two cancer-cell lines with ECs0 from 22.8 to 76.4 mM and from 54.9 to 82.4 mM, respectively. And the other compounds did not demonstrate any significant cytotoxicity even at concentrations up to 200 mM.
基金the Educational Administration Key Project of Shandong province (No. J01C05) and the Outstanding Adult-Young Scientific Research Encouraging Foundation of Shandong province (No. O1BS18)
文摘The title compound (PhNHNH)2C=OCH3CN has been prepared and characterized by elemental analysis and IR spectrum studies. The single-crystal X-ray structure determination of the title compound was carried out. It crystallizes in the monoclinic system, space group P21/n with a = 5.7818(2), b = 15.320(1), c = 17.469(1) ? b = 97.476(1)? V = 1534.2(1) 3, Mr = 283.34 (C15H17N5O), Z = 4, Dc = 1.227 g/cm3 , F(000) = 600, ?= 0.082 mm-1, R = 0.0561 and wR = 0.1538. The total reflections were 8214 and the independent ones were 2624 (Rint = 0.0559), of which 1756 were observed with I > 2s(I). The torsion angles of the important groups (C(6)N(1) N(2)C(7) and C(7)N(3)N(4)C(8)) are 68.3(3) and 93.3(3), respectively. In the crystal lattice, the molecules form a network structure through hydrogen bonds. The crystal structure is stabilized by NH…N and NH…O hydrogen bonds. FT-IR spectra clearly show there exist acetonitrile molecules in the crystal lattice.
文摘Pollution of environment, connected with intensive industry and, as a result, declination of health of nation is one of the biggest problems of modem age. The purpose of research was the studying of influence of hydrazine derivatives on redistribution of plasma protein between blood and lymph and change of hemodynamic poisoned by 1, l-nitrozodimethylamine. parameter caused by this. There were some changes in organism
文摘The results of field tests of the catalyst ＂Mukhamedzhan-l＂ for the detoxification of propellant UDMH （unsymmetrical dimethylhydrazine） in the position the space center ＂Baikonur＂ in Kazakhstan were studied. Results of field tests have shown high efficiency of the catalyst ＂Mukhamedzhan- 1＂ for detoxification UDMH.
