A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operati...A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.展开更多
In recent years, there has been a considerable research interest in moving-bed biofilm reactor（MBBR） for its efficiency and stability. This work proposes a new way to modify the hydrophilicity of polyurethane foam...In recent years, there has been a considerable research interest in moving-bed biofilm reactor（MBBR） for its efficiency and stability. This work proposes a new way to modify the hydrophilicity of polyurethane foam（PU） carriers via the layer-by-layer self-assembly of hyperbranched polymeric diazonium salt（M-HB-DAS） and poly（sodium-p-styrenesulfonate）（PSS）. Modified carriers showed very good adsorption for microbes according to the results of scanning electron microscope（SEM）. Biochemical experiments on wastewater treatment confirm that the modified PU carriers can improve the removal rate of chemical oxygen demand（COD）.展开更多
4-Nitro-benzendiazonium (4-NBD) was found to form a 1:1 host-guest complex (NBD@CB) with cucurbit[7]uril (CB[7]) in aqueous solution and 4-NBD enters into the cavity of CB[7] with a binding constant of1.28 x 10~5 L/mo...4-Nitro-benzendiazonium (4-NBD) was found to form a 1:1 host-guest complex (NBD@CB) with cucurbit[7]uril (CB[7]) in aqueous solution and 4-NBD enters into the cavity of CB[7] with a binding constant of1.28 x 10~5 L/mol. NBD@CB can be decomposed into a nitrobenzene/4-nitrophenol mixture in a high total yield (61 %+ 33%) in the presence of CuCl, unlike the decomposition of 4-NBD in the presence of either CB[7] or CuCl, or both absence, where would result in significant amounts of unknown byproducts. This work might provide an economic and effective way to obtain arenes or phenols through the substitution of diazonium salts.展开更多
An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0...An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0-5 ℃, solvent： water） within a short reaction time （1 h）. A plausible substitution reaction mechanism by phenol-ketone resonance was proposed.展开更多
The novel use of p-nitrophenyldiazonium tetrafluoroborate salt(GG salt)as a protectant that is electrochemically grafted onto carbon steel has been investigated in0.05 mol L-1H2SO4and 5 wt%NaCl solutions using various...The novel use of p-nitrophenyldiazonium tetrafluoroborate salt(GG salt)as a protectant that is electrochemically grafted onto carbon steel has been investigated in0.05 mol L-1H2SO4and 5 wt%NaCl solutions using various corrosion monitoring techniques,such as electrochemical impedance spectroscopy,potentiodynamic polarisation,infrared spectra and scanning electron microscopy measurements.The electrochemical study reveals that this compound is a mixed inhibitor that predominantly controls the cathodic reaction.The surface-grafted film decreases the double-layer capacitance and obviously increases the charge transfer resistance relative to a bare carbon electrode.The values of inhibition effect remain nearly unchanged with an increase in temperature range of 298–318 K.The aryl diazonium is covalently bonded on the steel surface,causing a slight decrease in the apparent activation energy.Overall,the surface-grafted films exhibit excellent inhibition performance in acid and saline solutions within the studied temperature range.展开更多
This work contributes to the improvement of the azo group which has outstanding electron donating capability and serves as excellent ligands in the field of coordination chemistry. The authors of this research deal wi...This work contributes to the improvement of the azo group which has outstanding electron donating capability and serves as excellent ligands in the field of coordination chemistry. The authors of this research deal with the microwave irradiation synthesis of some new Schiff bases derived from the biologically effective and photoactive Congo red [Ia-g]. The design and preparation of the structurally reversed analogous compounds to the above compounds [IIIa-d] were accomplished using the conventional chemical methods by keeping the benzidine moiety of Congo red as the nucleus of the synthesized compounds, doubling the number of the azo groups and inverting the way of their conjugation order with the azomethine groups. The structures of the newly prepared compounds were established on the basis of their FTIR and H1 NMR spectral data.展开更多
Diazonium chlorides of 5-amino-3-methypyrazole 1a and 5-amino-4-phenylpyrazole 1b coupled with 1,3-indanedione 2 and led to the formation of acyclic hydrazone 3a and a cyclic product indenopyrazolotriazine 4b respecti...Diazonium chlorides of 5-amino-3-methypyrazole 1a and 5-amino-4-phenylpyrazole 1b coupled with 1,3-indanedione 2 and led to the formation of acyclic hydrazone 3a and a cyclic product indenopyrazolotriazine 4b respectively. Cyclization of the hydrazone 3a by boiling in acetic acid afforded the corresponding 4a. The hydrazone 3a reacted with malononitrile in boiling ethanol in the presence of piperidine and gave indeno[2,1-c]pyridazine-4-carbonitrile derivatives 5a,b. Also, coupling of 6 with aryl diazonium chlorides gave the corresponding indenopyridazine derivatives 8a-e. Acetylation, benzoylation and hydrolysis of compound 8a afforded the corresponding substitution products 10-12, respectively. The structures of the newly synthesized compounds were established on the basis of chemical and spectral evidences.展开更多
Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors wi...Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors with aryl diazonium salts has been accomplished under metal-free conditions with exclusive regioselectivity. This transformation provides practical access to a broad panel of 2-aryl-2 H-tetrazol-5-yl difluoromethylene phosphonates, including the corresponding derivatives of amino acid(phenylalanine) and drug cores(Pomalidomide and Lapatinib fragment).展开更多
Patterned covalent functionalization of graphitic surfaces(GSs)is of interest in the development of devices and nanocomposite materials.In contrast to the strategies using external templates or control for realizing p...Patterned covalent functionalization of graphitic surfaces(GSs)is of interest in the development of devices and nanocomposite materials.In contrast to the strategies using external templates or control for realizing patterned covalent functionalization of GSs,here,we present a self-templated strategy by exploiting the synergistic effects of chemical and physical functionalization of GSs.Therefore,a diazonium salt is reduced by potassium iodide(KI)in dimethyl sulfoxide while the solution is in contact with a GS,resulting in its spatially heterogeneous,that is,chemical and physical,functionalization.This heterogeneous functionalization leads to a quasiperiodic pattern of striped corrals with three equivalent orientations in the covalent layer.The formation of the striped corrals is ascribed to physisorbed domains formed by self-assembled N_(2),which is produced in situ during the reduction of the diazonium salt,preventing the covalent functionalization.展开更多
基金Supported by the Science and Technology Key Projects of Shanxi Province(20090321113)
文摘A new type of reactor,featured with impinging stream-rotating packed bed（IS-RPB）and coil pipes,was designed and used to prepare p-hydroxybenzaldehyde（PHB）by hydrolysis from diazonium salts.The influence of operating parameters,such as reaction temperature,reaction time and high gravity factor,on the yield of PHB was investigated.Compared with the traditional kettle-type reactor,the yield of PHB with the new reactor is increased significantly and the reaction time is much shorter.Under the optimum conditions,the yield of PHB is increased from 51%to 84.1%.The reactor offers an opportunity for replacing the traditional batch mode operation with a continuous process.
基金Supported by the National Natural Science Foundation of China（Nos.21474056, 21674058）.
文摘In recent years, there has been a considerable research interest in moving-bed biofilm reactor（MBBR） for its efficiency and stability. This work proposes a new way to modify the hydrophilicity of polyurethane foam（PU） carriers via the layer-by-layer self-assembly of hyperbranched polymeric diazonium salt（M-HB-DAS） and poly（sodium-p-styrenesulfonate）（PSS）. Modified carriers showed very good adsorption for microbes according to the results of scanning electron microscope（SEM）. Biochemical experiments on wastewater treatment confirm that the modified PU carriers can improve the removal rate of chemical oxygen demand（COD）.
基金financially supported by the National Natural Science Foundation of China (Nos. 21572063 and 21372076)the Science Fund for Creative Research Groups (No. 21421004)+1 种基金the Program of Introducing Talents of Discipline to Universities (No. B16017)the Fundamental Research Funds for the Central Universities (No. 222201717003)
文摘4-Nitro-benzendiazonium (4-NBD) was found to form a 1:1 host-guest complex (NBD@CB) with cucurbit[7]uril (CB[7]) in aqueous solution and 4-NBD enters into the cavity of CB[7] with a binding constant of1.28 x 10~5 L/mol. NBD@CB can be decomposed into a nitrobenzene/4-nitrophenol mixture in a high total yield (61 %+ 33%) in the presence of CuCl, unlike the decomposition of 4-NBD in the presence of either CB[7] or CuCl, or both absence, where would result in significant amounts of unknown byproducts. This work might provide an economic and effective way to obtain arenes or phenols through the substitution of diazonium salts.
基金supported by the National Natural Science Foundation for Young Scholar of China(No.21276042)the National Science and Technology Pillar Program(No. 2013BAF08B06)Jiaogai Foundation of DUT(No.JGXM201224)
文摘An unusual substitution reaction of an aromatic sulfonic group based on 3-carbonyl-4-phenolsulfonic acid was discovered in a diazo-coupling process. The reaction occurred under mild reaction conditions （pH 8.0-9.0, 0-5 ℃, solvent： water） within a short reaction time （1 h）. A plausible substitution reaction mechanism by phenol-ketone resonance was proposed.
基金supported by the National Natural Science Foundation of China(21103105)the Foundation for University Youth Teachers by the Shanghai Education Committeethe Innovation Fund of Shanghai University(50334040)
文摘The novel use of p-nitrophenyldiazonium tetrafluoroborate salt(GG salt)as a protectant that is electrochemically grafted onto carbon steel has been investigated in0.05 mol L-1H2SO4and 5 wt%NaCl solutions using various corrosion monitoring techniques,such as electrochemical impedance spectroscopy,potentiodynamic polarisation,infrared spectra and scanning electron microscopy measurements.The electrochemical study reveals that this compound is a mixed inhibitor that predominantly controls the cathodic reaction.The surface-grafted film decreases the double-layer capacitance and obviously increases the charge transfer resistance relative to a bare carbon electrode.The values of inhibition effect remain nearly unchanged with an increase in temperature range of 298–318 K.The aryl diazonium is covalently bonded on the steel surface,causing a slight decrease in the apparent activation energy.Overall,the surface-grafted films exhibit excellent inhibition performance in acid and saline solutions within the studied temperature range.
文摘This work contributes to the improvement of the azo group which has outstanding electron donating capability and serves as excellent ligands in the field of coordination chemistry. The authors of this research deal with the microwave irradiation synthesis of some new Schiff bases derived from the biologically effective and photoactive Congo red [Ia-g]. The design and preparation of the structurally reversed analogous compounds to the above compounds [IIIa-d] were accomplished using the conventional chemical methods by keeping the benzidine moiety of Congo red as the nucleus of the synthesized compounds, doubling the number of the azo groups and inverting the way of their conjugation order with the azomethine groups. The structures of the newly prepared compounds were established on the basis of their FTIR and H1 NMR spectral data.
文摘Diazonium chlorides of 5-amino-3-methypyrazole 1a and 5-amino-4-phenylpyrazole 1b coupled with 1,3-indanedione 2 and led to the formation of acyclic hydrazone 3a and a cyclic product indenopyrazolotriazine 4b respectively. Cyclization of the hydrazone 3a by boiling in acetic acid afforded the corresponding 4a. The hydrazone 3a reacted with malononitrile in boiling ethanol in the presence of piperidine and gave indeno[2,1-c]pyridazine-4-carbonitrile derivatives 5a,b. Also, coupling of 6 with aryl diazonium chlorides gave the corresponding indenopyridazine derivatives 8a-e. Acetylation, benzoylation and hydrolysis of compound 8a afforded the corresponding substitution products 10-12, respectively. The structures of the newly synthesized compounds were established on the basis of chemical and spectral evidences.
基金supported by the National Natural Science Foundation of China (Nos.21772142,21901181 and 21961142015)the National Key Research and Development Program of China (No.2019YFA0905100)+1 种基金Tianjin Municipal Science & Technology Commission (No.19JCQNJC04700)the CNRS in France。
文摘Three bench-stable difluoromethylene phosphonate hydrazones were prepared from simple diethyl(difluoromethyl)phosphonate within two steps in good yields. The [3 + 2] cycloaddition reaction of these diazo precursors with aryl diazonium salts has been accomplished under metal-free conditions with exclusive regioselectivity. This transformation provides practical access to a broad panel of 2-aryl-2 H-tetrazol-5-yl difluoromethylene phosphonates, including the corresponding derivatives of amino acid(phenylalanine) and drug cores(Pomalidomide and Lapatinib fragment).
基金Research Foundation-Flanders (FWO),Grant/Award Numbers:G081518N,G082218NKU Leuven-Internal Funds,Grant/Award Number:C14/19/079+2 种基金FWO under EOS,Grant/Award Number:30489208the China Scholarship Council,Grant/Award Number:CSC 201706890021Marie Skłodowska-Curie Individual Fellowship,Grant/Award Number:789865-EnSurf。
文摘Patterned covalent functionalization of graphitic surfaces(GSs)is of interest in the development of devices and nanocomposite materials.In contrast to the strategies using external templates or control for realizing patterned covalent functionalization of GSs,here,we present a self-templated strategy by exploiting the synergistic effects of chemical and physical functionalization of GSs.Therefore,a diazonium salt is reduced by potassium iodide(KI)in dimethyl sulfoxide while the solution is in contact with a GS,resulting in its spatially heterogeneous,that is,chemical and physical,functionalization.This heterogeneous functionalization leads to a quasiperiodic pattern of striped corrals with three equivalent orientations in the covalent layer.The formation of the striped corrals is ascribed to physisorbed domains formed by self-assembled N_(2),which is produced in situ during the reduction of the diazonium salt,preventing the covalent functionalization.
