Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with i...Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with initial concentration of 48μmol/L （20 mg/L） was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe（Ⅲ） initiated degradation of PFOA irradiated with 254 nm UV light.展开更多
A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At ...A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.展开更多
The flexibility of molecular catalysts is highly coveted for the electrochemical reduction of carbon dioxide(CO_(2)) to carbon monoxide(CO) in both homogeneous and heterogeneous systems.While the electrocatalytic acti...The flexibility of molecular catalysts is highly coveted for the electrochemical reduction of carbon dioxide(CO_(2)) to carbon monoxide(CO) in both homogeneous and heterogeneous systems.While the electrocatalytic activity of molecular catalysts has been widely studied in H-cells;their less studied capabilities in more efficient flow cell reactors have the potential to rival that of heterogeneous catalysts.In this work,a comparative study of amino functionalized iron-tetraphenylporphyrins(amino-Fe-TPPs) immobilized onto carbonaceous materials in both H-cells and flow cells was conducted to selectively reduce CO_(2) to CO.In a flow cell set up operating in alkaline media,the resulting hybrid catalyst exhibits 87% faradaic efficiency(FE) with extraordinary current density(j) of 119 mA/cm^(2) and turnover frequency(TOF) of 14 s^(-1) at-1.0 V vs.RHE.This remarkable catalytic activity was achieved through thoughtful combination of molecular and flow cell design that provides an effective strategy for future immobilized heterogeneous approaches toward CO_(2) reduction reactions(CO_(2) RRs).展开更多
Hydrogen evolution in the presence of atmospheric level of oxygen is a significant barrier in the quest for an alternative,sustainable and green source of energy to counter the depleting fossil fuel sources and increa...Hydrogen evolution in the presence of atmospheric level of oxygen is a significant barrier in the quest for an alternative,sustainable and green source of energy to counter the depleting fossil fuel sources and increasing global warming due to fossil fuel burning.Oxygen reduction is thermodynamically more favourable than proton reduction and it often produces reactive oxygenated species upon partial reduction which deactivates the catalyst.Thus,catalyst development is required for efficient proton reduction in the presence of oxygen.Here,we demonstrate an iron porphyrin having triazole containing 2nd sphere hydrogen bonding residues appended with redox active ferrocene moieties(α4-Tetra-2-(3-ferrocenyl-1,2,3-triazolyl)phenylporphyrin(FeFc4))as a bifunctional catalyst for fast and selective oxygen reduction to water and thus,preventing the proton reduction by the same catalyst from oxidative stress.Fe(0)is the active species for proton reduction in these iron porphyrin class of complexes and it is observed that the kinetics of proton reduction at Fe(0)state occurs at much faster rate than O2 reduction and thus,paving the way for selective proton reduction in the presence of oxygen.展开更多
The geometry optimizations and the single point energy calculations of iron tetraphenylporphyrin chloride Fe（TPP）Cl and iron tetraphenylporphyrin chloride （Fe（TPP）Cl）, iron pentafluorophenylporphyrin chloride ...The geometry optimizations and the single point energy calculations of iron tetraphenylporphyrin chloride Fe（TPP）Cl and iron tetraphenylporphyrin chloride （Fe（TPP）Cl）, iron pentafluorophenylporphyrin chloride （Fe（TPPF20）Cl） were carried out by using the Density Functional Theory （DFT） UB3LYP with STO-3G^＊ and 6-31G^＊ basis sets, respectively. The electronic properties and the structures of high-lying molecular orbitals were analyzed in detail. The results show that partial spin is transferred from the Fe atom to the porphyrin ring and some electron with the spin opposite to the unpaired electron on the Fe atom is transferred from the porphyrin ring to the Fe atom. The π and σ-type bonding between the Fe atom and the porphyin ring cause the transfer. The fluorination enhances the electron transfer and the chemical stability of the complex. The high stability is important for the complex possessing high catalytic activity. The catalysis mechanism of oxygen molecule activation on the complex surface is also discussed based on the symmetry of the molecular orbitals.展开更多
The electrocatalytic CO_(2)reduction reaction(CO_(2)RR)has attracted increasing attention in recentyears.Practical electrocatalysis of CO_(2)RR must be carried out in aqueous solutions containing electrolytesof alkali...The electrocatalytic CO_(2)reduction reaction(CO_(2)RR)has attracted increasing attention in recentyears.Practical electrocatalysis of CO_(2)RR must be carried out in aqueous solutions containing electrolytesof alkali metal cations such as sodium and potassium.Although considerable efforts havebeen made to design efficient electrocatalysts for CO_(2)RR and to investigate the structure–activityrelationships using molecular model complexes,only a few studies have been investigated the effectof alkali metal cations on electrocatalytic CO_(2)RR.In this study,we report the effect of alkali metalcations(Na^(+)and K^(+))on electrocatalytic CO_(2)RR with Fe porphyrins.By running CO_(2)RR electrocatalysisin dimethylformamide(DMF),we found that the addition of Na^(+)or K^(+)considerably improves thecatalytic activity of Fe chloride tetrakis(3,4,5‐trimethoxyphenyl)porphyrin(FeP).Based on thisresult,we synthesized an Fe porphyrin^(N)18C6‐FeP bearing a tethered 1‐aza‐18‐crown‐6‐ether(^(N)18C6)group at the second coordination sphere of the Fe site.We showed that with the tethered^(N)18C6 to bind Na^(+)or K^(+),^(N)18C6‐FeP is more active than FeP for electrocatalytic CO_(2)RR.This workdemonstrates the positive effect of alkali metal cations to improve CO_(2)RR electrocatalysis,which isvaluable for the rational design of new efficient catalysts.展开更多
The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of sali...The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.展开更多
Reaction of 3,5-pyridine-dicarboxylic acid（3,5-PydcH2） with iron salt in hydrothermal condition results in the formation of a three-dimensional self-assembly network formulated as [C14H14Fe2N2O12]n,and it has been s...Reaction of 3,5-pyridine-dicarboxylic acid（3,5-PydcH2） with iron salt in hydrothermal condition results in the formation of a three-dimensional self-assembly network formulated as [C14H14Fe2N2O12]n,and it has been structurally characterized by elemental analysis,IR spectra and X-ray diffraction.It crystallizes in the monoclinic system,space group C2/c with a=9.9633（15）,b=12.0942（18）,c=7.4297（11）A and β=105.822o.The units of Fe2（pydc）2·2H2O are linked into a one-dimensional structure via the chelate carboxylate groups from the 3,5-pyridine-dicarboxylate.The interlayer hydrogen bonding interactions result in a three-dimensional supramolecular architecture.In the complex,the Fe（Ⅲ） ion displays a slightly distorted pentagonal bipyramidal geometry with seven coordination numbers.Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are quasi-reversible in nature.展开更多
The structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.3...The structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.33） crystallizes in the monoclinic space group P2 1/c with a=8.4615（17）,b=33.704（7）,c=11.173（2）,β=91.12（3）o,V=3185.7（11）3,Z=4,D c=1.585 g/cm 3,μ（MoK）=0.970 mm-1,F（000）=1552,R int=0.0381,the final R=0.0454 and wR=0.1114.The magnetic susceptibilities of the complex have been examined in the temperature range of 2-300 K.The magnetic data were fitted to give the parameters of J d=-77.7（9） and J c=-11.5（6） cm-1.展开更多
Iron porphyrins have high activity and selectivity for electrocatalytic CO_(2)reduction reaction(CO_(2)RR)in nonaqueous solutions,but they usually display poor or moderate selectivity for CO_(2)RR in aqueous solutions...Iron porphyrins have high activity and selectivity for electrocatalytic CO_(2)reduction reaction(CO_(2)RR)in nonaqueous solutions,but they usually display poor or moderate selectivity for CO_(2)RR in aqueous solutions because of the competitive hydrogen evolution reaction.Using water as the electrocatalytic reaction solvent is more favored because not only it is cheap,green and abundant but also it can sufficiently provide protons required for CO_(2)RR.Therefore,developing Fe porphyrins as electrocatalysts for efficient and selective CO_(2)RR in aqueous solutions is of both fundamental and practical significance.Herein,we report the design and synthesis of Fe porphyrin 1 with an appended guanidyl group and its electrocatalytic features for CO_(2)RR in both nonaqueous and aqueous solutions.In acetonitrile,Fe porphyrin 1 and its guanidyl-free analogue,tetrakis(3,4,5-trimethoxyphenyl)porphyrin 2,are both efficient for electrocatalytic CO_(2)-to-CO conversion,but the turnover frequency with 1(3.9´10^(5)s^(-1))is one order of magnitude larger than that with 2(1.7´10^(4)s^(-1)),showing the critical role of the appended guanidyl group in improving electrocatalytic CO_(2)RR activity.More importantly,in 0.1 mol L^(-1)KHCO_(3)aqueous solutions,1 showed very high selectivity for electrocatalytic CO_(2)-to-CO conversion with a Faradaic efficiency of 96%,while 2 displayed a Faradaic efficiency of 65%for the CO_(2)-to-CO conversion.This work is of significance to show the effect of appended guanidyl group on improving both activity and selectivity of Fe porphyrins for CO_(2)RR electrocatalysis.展开更多
Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as mo...Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as model azo dyes. The effect of parameters such as contact time and initial dye concentration on the adsorption of azo dyes was studied. The results showed that loading of Fe(Ⅲ) onto the sorbent networks has noticeable effect on azo-dye sorption capacity. The adsorption equilibrium data were fitted to Freundlich isotherm model. Besides, the reusability of the dye loaded sorbents was investigated on adjusting pH of solutions.展开更多
Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher ...Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher enantioselectivity were obtained with combined use of molecular oxygen and an aldehyde at 30℃, Some factors influencing enantioselectivity were discussed.展开更多
文摘Environmentally persistent and bioaccumulative perfluorooctanic acid （PFOA） was difficult to be decomposed under the irradiation of 254 nm UV light. However, in the presence of 80μmol/L Fe（Ⅲ）, 80% of PFOA with initial concentration of 48μmol/L （20 mg/L） was effectively degraded and 47.8% of fluorine atoms in PFOA molecule were transformed into inorganic fluoride ion after 4 h reaction. Shorter chain perfluorocarboxylic acids bearing C3-C7 and fluoride ion were detected and identified by LC/MS and IC as the degradation products in the aqueous solution. It was proposed that complexes of PFOA with Fe（Ⅲ） initiated degradation of PFOA irradiated with 254 nm UV light.
文摘A selective and sensitive reagent of 2-pyridine carboxaldehyde isonicotinyl hydrazone（2-PYAINH） was synthesized and studied for the spectrophotometric determination of nickel, copper, cobalt, and iron in detail. At a pH value of 7.0, 9,0, 9.0, and 8.0, respectively, which greatly increased the selectivity; nickel, copper, cobalt, and iron reacted with 2-PYAINH to form a 1：2 yellow-orange, 1：2 yellow-green, 1：2 yellow and 1：1 yellow complexes, with absorption peaks at 363, 352, 346, and 359 nm, respectively. Under the optimal conditions, Beer＇s law was obeyed over the ranges of 0.01-1.4, 0.01-1.5, 0.01-2.7, and 0.01-5.4 mg/L respectively. The apparent molar absorptivity and Sandell＇s sensitivities were 8.4×10^4, 5.2×10^4, 7.1×10^4, and 3.9×10^4 L·mol^-l·cm^-1, respectively, and 0.00069, 0.0012, 0.00078, and 0.0014 μg·cm2, respectively. The detection limits were found to be 0.001, 0.002, 0.003, and 0.01 mg/L, respectively. The detailed study of various interfering ions to make the method more sensitive was carried out and selective and several real samples were analyzed with satisfactory results.
基金supported by NSERC DG 2016-06122 and 201606589 through Discovery Grants to HBK and X.A.Z.,respectivelyby the Canada Foundation for Innovation,Canada Research Chair,and the Ontario Research Fund。
文摘The flexibility of molecular catalysts is highly coveted for the electrochemical reduction of carbon dioxide(CO_(2)) to carbon monoxide(CO) in both homogeneous and heterogeneous systems.While the electrocatalytic activity of molecular catalysts has been widely studied in H-cells;their less studied capabilities in more efficient flow cell reactors have the potential to rival that of heterogeneous catalysts.In this work,a comparative study of amino functionalized iron-tetraphenylporphyrins(amino-Fe-TPPs) immobilized onto carbonaceous materials in both H-cells and flow cells was conducted to selectively reduce CO_(2) to CO.In a flow cell set up operating in alkaline media,the resulting hybrid catalyst exhibits 87% faradaic efficiency(FE) with extraordinary current density(j) of 119 mA/cm^(2) and turnover frequency(TOF) of 14 s^(-1) at-1.0 V vs.RHE.This remarkable catalytic activity was achieved through thoughtful combination of molecular and flow cell design that provides an effective strategy for future immobilized heterogeneous approaches toward CO_(2) reduction reactions(CO_(2) RRs).
文摘Hydrogen evolution in the presence of atmospheric level of oxygen is a significant barrier in the quest for an alternative,sustainable and green source of energy to counter the depleting fossil fuel sources and increasing global warming due to fossil fuel burning.Oxygen reduction is thermodynamically more favourable than proton reduction and it often produces reactive oxygenated species upon partial reduction which deactivates the catalyst.Thus,catalyst development is required for efficient proton reduction in the presence of oxygen.Here,we demonstrate an iron porphyrin having triazole containing 2nd sphere hydrogen bonding residues appended with redox active ferrocene moieties(α4-Tetra-2-(3-ferrocenyl-1,2,3-triazolyl)phenylporphyrin(FeFc4))as a bifunctional catalyst for fast and selective oxygen reduction to water and thus,preventing the proton reduction by the same catalyst from oxidative stress.Fe(0)is the active species for proton reduction in these iron porphyrin class of complexes and it is observed that the kinetics of proton reduction at Fe(0)state occurs at much faster rate than O2 reduction and thus,paving the way for selective proton reduction in the presence of oxygen.
基金ACKN0WLEDGMENT This work was supported by the National Natural Science Foundation of China （No.20443002） and the Science Foundations of Henan Province for 0utstanding Young Scientists （No.0612002600）
文摘The geometry optimizations and the single point energy calculations of iron tetraphenylporphyrin chloride Fe（TPP）Cl and iron tetraphenylporphyrin chloride （Fe（TPP）Cl）, iron pentafluorophenylporphyrin chloride （Fe（TPPF20）Cl） were carried out by using the Density Functional Theory （DFT） UB3LYP with STO-3G^＊ and 6-31G^＊ basis sets, respectively. The electronic properties and the structures of high-lying molecular orbitals were analyzed in detail. The results show that partial spin is transferred from the Fe atom to the porphyrin ring and some electron with the spin opposite to the unpaired electron on the Fe atom is transferred from the porphyrin ring to the Fe atom. The π and σ-type bonding between the Fe atom and the porphyin ring cause the transfer. The fluorination enhances the electron transfer and the chemical stability of the complex. The high stability is important for the complex possessing high catalytic activity. The catalysis mechanism of oxygen molecule activation on the complex surface is also discussed based on the symmetry of the molecular orbitals.
文摘The electrocatalytic CO_(2)reduction reaction(CO_(2)RR)has attracted increasing attention in recentyears.Practical electrocatalysis of CO_(2)RR must be carried out in aqueous solutions containing electrolytesof alkali metal cations such as sodium and potassium.Although considerable efforts havebeen made to design efficient electrocatalysts for CO_(2)RR and to investigate the structure–activityrelationships using molecular model complexes,only a few studies have been investigated the effectof alkali metal cations on electrocatalytic CO_(2)RR.In this study,we report the effect of alkali metalcations(Na^(+)and K^(+))on electrocatalytic CO_(2)RR with Fe porphyrins.By running CO_(2)RR electrocatalysisin dimethylformamide(DMF),we found that the addition of Na^(+)or K^(+)considerably improves thecatalytic activity of Fe chloride tetrakis(3,4,5‐trimethoxyphenyl)porphyrin(FeP).Based on thisresult,we synthesized an Fe porphyrin^(N)18C6‐FeP bearing a tethered 1‐aza‐18‐crown‐6‐ether(^(N)18C6)group at the second coordination sphere of the Fe site.We showed that with the tethered^(N)18C6 to bind Na^(+)or K^(+),^(N)18C6‐FeP is more active than FeP for electrocatalytic CO_(2)RR.This workdemonstrates the positive effect of alkali metal cations to improve CO_(2)RR electrocatalysis,which isvaluable for the rational design of new efficient catalysts.
文摘The coordination nature of a number of substituted sodiumphenoxides to iron （Ⅲ） ion has been studied. The o-nitrosodiumphenoxide was found to have different coordination behaviour from that the sodium salts of salicylic acid and methylsalicylate showed. The structure of the complexes, the number of the ligands being coordinated to the metal ion, has also been determined by titration, uv-vis spectroscopy, atomic absorption and the flame test. In addition, other sodium phenoxides were also involved in this study for comparison. An electric conductivity study on the resulting complexes was carried out and all complexes were found to be semiconductors.
基金supported by the National Natural Science Foundation of China (Nos 20771054 and 20671076)the Natural Science Foundation of Henan Province (No 0311021200)
文摘Reaction of 3,5-pyridine-dicarboxylic acid（3,5-PydcH2） with iron salt in hydrothermal condition results in the formation of a three-dimensional self-assembly network formulated as [C14H14Fe2N2O12]n,and it has been structurally characterized by elemental analysis,IR spectra and X-ray diffraction.It crystallizes in the monoclinic system,space group C2/c with a=9.9633（15）,b=12.0942（18）,c=7.4297（11）A and β=105.822o.The units of Fe2（pydc）2·2H2O are linked into a one-dimensional structure via the chelate carboxylate groups from the 3,5-pyridine-dicarboxylate.The interlayer hydrogen bonding interactions result in a three-dimensional supramolecular architecture.In the complex,the Fe（Ⅲ） ion displays a slightly distorted pentagonal bipyramidal geometry with seven coordination numbers.Cyclic-voltammetry measurement reveals the oxidation and reduction processes for the complex are quasi-reversible in nature.
基金supported by the Natural Science Foundation of China (No. 2117624)the Fundamental Research Funds for the Central Universities (China University of Mining and Technology)
文摘The structure of the title complex [Fe2（μ-O）（bpb）2]n （bpb 2=1,2-bis（pyridine-2carboxamido） benzenate） has been characterized by single-crystal X-ray diffraction analysis.The complex （C36 H24 Fe2N8O5,Mr=760.33） crystallizes in the monoclinic space group P2 1/c with a=8.4615（17）,b=33.704（7）,c=11.173（2）,β=91.12（3）o,V=3185.7（11）3,Z=4,D c=1.585 g/cm 3,μ（MoK）=0.970 mm-1,F（000）=1552,R int=0.0381,the final R=0.0454 and wR=0.1114.The magnetic susceptibilities of the complex have been examined in the temperature range of 2-300 K.The magnetic data were fitted to give the parameters of J d=-77.7（9） and J c=-11.5（6） cm-1.
文摘Iron porphyrins have high activity and selectivity for electrocatalytic CO_(2)reduction reaction(CO_(2)RR)in nonaqueous solutions,but they usually display poor or moderate selectivity for CO_(2)RR in aqueous solutions because of the competitive hydrogen evolution reaction.Using water as the electrocatalytic reaction solvent is more favored because not only it is cheap,green and abundant but also it can sufficiently provide protons required for CO_(2)RR.Therefore,developing Fe porphyrins as electrocatalysts for efficient and selective CO_(2)RR in aqueous solutions is of both fundamental and practical significance.Herein,we report the design and synthesis of Fe porphyrin 1 with an appended guanidyl group and its electrocatalytic features for CO_(2)RR in both nonaqueous and aqueous solutions.In acetonitrile,Fe porphyrin 1 and its guanidyl-free analogue,tetrakis(3,4,5-trimethoxyphenyl)porphyrin 2,are both efficient for electrocatalytic CO_(2)-to-CO conversion,but the turnover frequency with 1(3.9´10^(5)s^(-1))is one order of magnitude larger than that with 2(1.7´10^(4)s^(-1)),showing the critical role of the appended guanidyl group in improving electrocatalytic CO_(2)RR activity.More importantly,in 0.1 mol L^(-1)KHCO_(3)aqueous solutions,1 showed very high selectivity for electrocatalytic CO_(2)-to-CO conversion with a Faradaic efficiency of 96%,while 2 displayed a Faradaic efficiency of 65%for the CO_(2)-to-CO conversion.This work is of significance to show the effect of appended guanidyl group on improving both activity and selectivity of Fe porphyrins for CO_(2)RR electrocatalysis.
文摘Iron(Ⅲ) loaded novolac-based network adsorbents 1 and 2 were studied for efficient removal of azo-dye pollutants from aqueous solutions. The adsorption behavior was evaluated by using methyl orange and orange-G as model azo dyes. The effect of parameters such as contact time and initial dye concentration on the adsorption of azo dyes was studied. The results showed that loading of Fe(Ⅲ) onto the sorbent networks has noticeable effect on azo-dye sorption capacity. The adsorption equilibrium data were fitted to Freundlich isotherm model. Besides, the reusability of the dye loaded sorbents was investigated on adjusting pH of solutions.
文摘Tris（d,d-dicampholylmethanato） iron （Ⅲ） complex, Fe（dcm）3, was found to be an excellent catalyst for asymmetric oxygenation of styrene analogues into the corresponding epoxides. Good chemical yields and higher enantioselectivity were obtained with combined use of molecular oxygen and an aldehyde at 30℃, Some factors influencing enantioselectivity were discussed.
