The complex Mn(apo)6Cl2 (apo=2-aminopyridine N-oxide) was obtained by the reaction of MnCl2(4H2O with apo(HCl and NaOH in ethanol. A single-crystal X-ray study shows that the complex is mononuclear with octahedral coo...The complex Mn(apo)6Cl2 (apo=2-aminopyridine N-oxide) was obtained by the reaction of MnCl2(4H2O with apo(HCl and NaOH in ethanol. A single-crystal X-ray study shows that the complex is mononuclear with octahedral coordination environment (MnC30H36N12O6Cl2). The oxygen atoms from apo ligands coordinate to the manganese atom forming Mn(apo)6Cl2. The compound Mn(apo)6Cl2 is hexagonally symmetric with space group R3, lattice constants: a = 12.010(2), b = 12.010(2), c = 20.232(4) ?, ( = 120(, V= 2527.4(7) ?3, Z=3, Mr =786.55, Dc=1.550 g/cm3, (= 0.614mm-1, F(000) = 1221, R = 0.0541, Rw = 0.0580 for 1229 reflections with I>2((I). The distances between Mn(II) and O atoms are in the range from 2.171(5) to 2.184(5) ?, and the distance between the chlorine anion and N atom of amido group is 3.3 ?. The dihedral angle between two adjacent pyridine ring planes is 59.19 (0.17)°.展开更多
The reported X-ray structure and magnetochemical properties of [Mn6O2 (OCPh)10, (CH3CN)4], effectively derived from [NBu4][Mn4O2(O2CPh)9 (H2O)] with equivalent of tren in CH3CN is shown.
The title complex, [Mn2(O-Py3A)(DPK-CH3O)(CH3OH)]2?2ClO4?4CH3OH (C64H70Cl2- Mn4N12O22, Py3AH = N-(bis(2?-pyridyl)methyl)-2-pyridinecarboxamide, DPK = di-2-pyridyl ketone) has been synthesized and its crystal structu...The title complex, [Mn2(O-Py3A)(DPK-CH3O)(CH3OH)]2?2ClO4?4CH3OH (C64H70Cl2- Mn4N12O22, Py3AH = N-(bis(2?-pyridyl)methyl)-2-pyridinecarboxamide, DPK = di-2-pyridyl ketone) has been synthesized and its crystal structure was determined by X-ray diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 12.667(9), b = 16.793(12), c = 17.070(13) ?, β = 100.997(13)o, V = 3565(5) ?3, Dc = 1.537 g/cm3, Mr = 1649.98, Z = 2, μ(MoKα) = 0.851 mm-1 and F(000) = 1696. The final R and wR are 0.0639 and 0.1320, respectively for 3979 observed reflec- tions with I > 2σ(I). In the tetranuclear complex, each Mn(II) atom is six-coordinated and the four Mn(II) atoms are coplanar, exhibiting a parallelogram arrangement; while the deprotonated ligands are oxidized to O-Py3A2- anions and cleaved to DPK-CH3O– anions (the monoanion of mono- methylated diol of DPK) furthermore.展开更多
ive binuclear Mn( Ⅱ ) complexes were synthesized, namely [Mn2LCl]Cl2 .H2O (1) , [Mn2LphCOO] (ClO4 )2 (2) , [Mn2LOH] (ClO4 )2 · C2H5OH (3 ) ,[Mn2LC2H5O](ClO4)2 ·H2O (4) , and [Mn2L(SCN)3] ·2C2H5OH (5) ...ive binuclear Mn( Ⅱ ) complexes were synthesized, namely [Mn2LCl]Cl2 .H2O (1) , [Mn2LphCOO] (ClO4 )2 (2) , [Mn2LOH] (ClO4 )2 · C2H5OH (3 ) ,[Mn2LC2H5O](ClO4)2 ·H2O (4) , and [Mn2L(SCN)3] ·2C2H5OH (5) , where HLis 1 : 2 Schiff bases derived from 1 , 3- diaminopropan-2-ol and picolinaldehyde N- ox-ide. Based on the IR, elemental analyses and conductivity measurement, these com- plexes are proposed to have an endogenous bridge (alkoxide) and an exogenousbridge (it can be an anion). The complexes (3) and (4) were characterized by vari-able temperature magnetic susceptibility (4 300 K) and the data were fitted by theleast-squares to a susceptibility equation derived from the spin Hamiltonian, H =- 2J · S1 · S2. The exchange integral J, was found to be 1. 19 cm-1 for (3) and 1. 06 cm-1 for (4) , indicating that a weak antiferromagnetic exchange is presentin the binuclear Mn( Ⅱ ) complexes.展开更多
The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of ...The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.展开更多
The polystyrene supported phenylalanine Schiff base complex of Mn(II) (PS-Sal-Phe-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-phenylalanine and manganese (II) acetate tet...The polystyrene supported phenylalanine Schiff base complex of Mn(II) (PS-Sal-Phe-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-phenylalanine and manganese (II) acetate tetrahyrate., The polymeric ligand and the complex were characterized by FT-IR,, small area X-ray photoelectron spectroscopy (XPS), and ICP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-1-ol (2), 2-cyclohexen-1-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.展开更多
The polystyrene supported glutamic acid Schiff base complex of Mn (Ⅱ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese (Ⅱ) acetate t...The polystyrene supported glutamic acid Schiff base complex of Mn (Ⅱ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese (Ⅱ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and ICP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-1-ol (2), 2-cyclohexen-1-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.展开更多
Conspectus:Redox reactions of Fe-and Mn-oxides play important roles in the fate and transformation of many contaminants in natural environments.Due to experimental and analytical challenges associated with complex env...Conspectus:Redox reactions of Fe-and Mn-oxides play important roles in the fate and transformation of many contaminants in natural environments.Due to experimental and analytical challenges associated with complex environments,there has been a limited understanding of the reaction kinetics and mechanisms in actual environmental systems,and most of the studies so far have only focused on simple model systems.To bridge the gap between simple model systems and complex environmental systems,it is necessary to increase the complexity of model systems and examine both the involved interaction mechanisms and how the interactions affected contaminant transformation.In this Account,we primarily focused on(1)the oxidative reactivity of Mn-and Fe-oxides and(2)the reductive reactivity of Fe(Ⅱ)/iron oxides in comolex model systems toward contaminant degradation.The effects of common metal ions such as Mn2+,Ca2+,Ni2+,Cr3+and Cu2+,ligands such as small anionic ligands and natural organic matter(NOM),and second metal oxides such as A1,Si and Ti oxides on the redox reactivity of the systems are briefly summarized.展开更多
Catalytic wet air oxidation(CWAO)is one of the most promising technologies for pollution abatement.Developing catalysts with high activity and stability is crucial for the application of the CWAO process.The Mn/Ce com...Catalytic wet air oxidation(CWAO)is one of the most promising technologies for pollution abatement.Developing catalysts with high activity and stability is crucial for the application of the CWAO process.The Mn/Ce com-plex oxide catalysts for CWAO of high concentration phenol-containing wastewater were prepared by coprecipitation.The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis.The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller(BET)analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry(ICP-AES).The results show that the catalysts have high catalytic activities even at a low temperature(80°C)and low oxygen partial pressure(0.5 MPa)in a batch reactor.The metallic ion leaching is comparatively low(Mn<6.577 mg/L and Ce<0.6910 mg/L,respectively)in the CWAO process.The phenol,COD_(Cr),and TOC removal efficiencies in the solution exceed 98.5%using the optimal catalyst(named CSP).The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater.展开更多
文摘The complex Mn(apo)6Cl2 (apo=2-aminopyridine N-oxide) was obtained by the reaction of MnCl2(4H2O with apo(HCl and NaOH in ethanol. A single-crystal X-ray study shows that the complex is mononuclear with octahedral coordination environment (MnC30H36N12O6Cl2). The oxygen atoms from apo ligands coordinate to the manganese atom forming Mn(apo)6Cl2. The compound Mn(apo)6Cl2 is hexagonally symmetric with space group R3, lattice constants: a = 12.010(2), b = 12.010(2), c = 20.232(4) ?, ( = 120(, V= 2527.4(7) ?3, Z=3, Mr =786.55, Dc=1.550 g/cm3, (= 0.614mm-1, F(000) = 1221, R = 0.0541, Rw = 0.0580 for 1229 reflections with I>2((I). The distances between Mn(II) and O atoms are in the range from 2.171(5) to 2.184(5) ?, and the distance between the chlorine anion and N atom of amido group is 3.3 ?. The dihedral angle between two adjacent pyridine ring planes is 59.19 (0.17)°.
文摘The reported X-ray structure and magnetochemical properties of [Mn6O2 (OCPh)10, (CH3CN)4], effectively derived from [NBu4][Mn4O2(O2CPh)9 (H2O)] with equivalent of tren in CH3CN is shown.
基金This work was financially supported by the Department of International Cooperation and Exchanges in Ministry of Education of China (No. (01)345)
文摘The title complex, [Mn2(O-Py3A)(DPK-CH3O)(CH3OH)]2?2ClO4?4CH3OH (C64H70Cl2- Mn4N12O22, Py3AH = N-(bis(2?-pyridyl)methyl)-2-pyridinecarboxamide, DPK = di-2-pyridyl ketone) has been synthesized and its crystal structure was determined by X-ray diffraction. It crystallizes in the monoclinic system, space group P21/n with a = 12.667(9), b = 16.793(12), c = 17.070(13) ?, β = 100.997(13)o, V = 3565(5) ?3, Dc = 1.537 g/cm3, Mr = 1649.98, Z = 2, μ(MoKα) = 0.851 mm-1 and F(000) = 1696. The final R and wR are 0.0639 and 0.1320, respectively for 3979 observed reflec- tions with I > 2σ(I). In the tetranuclear complex, each Mn(II) atom is six-coordinated and the four Mn(II) atoms are coplanar, exhibiting a parallelogram arrangement; while the deprotonated ligands are oxidized to O-Py3A2- anions and cleaved to DPK-CH3O– anions (the monoanion of mono- methylated diol of DPK) furthermore.
文摘ive binuclear Mn( Ⅱ ) complexes were synthesized, namely [Mn2LCl]Cl2 .H2O (1) , [Mn2LphCOO] (ClO4 )2 (2) , [Mn2LOH] (ClO4 )2 · C2H5OH (3 ) ,[Mn2LC2H5O](ClO4)2 ·H2O (4) , and [Mn2L(SCN)3] ·2C2H5OH (5) , where HLis 1 : 2 Schiff bases derived from 1 , 3- diaminopropan-2-ol and picolinaldehyde N- ox-ide. Based on the IR, elemental analyses and conductivity measurement, these com- plexes are proposed to have an endogenous bridge (alkoxide) and an exogenousbridge (it can be an anion). The complexes (3) and (4) were characterized by vari-able temperature magnetic susceptibility (4 300 K) and the data were fitted by theleast-squares to a susceptibility equation derived from the spin Hamiltonian, H =- 2J · S1 · S2. The exchange integral J, was found to be 1. 19 cm-1 for (3) and 1. 06 cm-1 for (4) , indicating that a weak antiferromagnetic exchange is presentin the binuclear Mn( Ⅱ ) complexes.
基金Project(76132020) supported by the Post-Doctoral Science Fund of Central South University
文摘The amino acid Schiff base complex (Sal-AMBA-Mn) was prepared with p-amino-methylbenzoic acid, salicylaldehyde and Mn(OAc)2·4H2O. Its structures was characterized with IR and UV spectra. Oxygenation mechanism of the complex in N, N-dimethylformamide solution was investigated. The results show that lower temperature is in favor of the oxygenation, and energy, enthalpy and entropy are -3.8 kJ/mol, -4.2 J/mol and -161.44 J/(mol·K), respectively. In the presence of the manganese complex, dehydroepiandrosterone acetate is effectively oxidized by molecular oxygen and the corresponding enone 7-ketodehydroepiandrosterone acetate is obtained. The yield is 62.1% when the oxidation is carried out under the reaction conditions of 60 ℃, 2 MPa of O2 pressure, C5H5N as a solvent and molar ratio of the substrate to the complex of 1:10.
文摘The polystyrene supported phenylalanine Schiff base complex of Mn(II) (PS-Sal-Phe-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-phenylalanine and manganese (II) acetate tetrahyrate., The polymeric ligand and the complex were characterized by FT-IR,, small area X-ray photoelectron spectroscopy (XPS), and ICP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-1-ol (2), 2-cyclohexen-1-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.
文摘The polystyrene supported glutamic acid Schiff base complex of Mn (Ⅱ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese (Ⅱ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and ICP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-1-ol (2), 2-cyclohexen-1-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed.
基金supported by the National Science Foundation under Grants CBET-1762691 and CHE-1808406 to H.Zhang.The authors are thankful to Dr.Zheng Li at University of Washington for the assistance for TOC drawing.
文摘Conspectus:Redox reactions of Fe-and Mn-oxides play important roles in the fate and transformation of many contaminants in natural environments.Due to experimental and analytical challenges associated with complex environments,there has been a limited understanding of the reaction kinetics and mechanisms in actual environmental systems,and most of the studies so far have only focused on simple model systems.To bridge the gap between simple model systems and complex environmental systems,it is necessary to increase the complexity of model systems and examine both the involved interaction mechanisms and how the interactions affected contaminant transformation.In this Account,we primarily focused on(1)the oxidative reactivity of Mn-and Fe-oxides and(2)the reductive reactivity of Fe(Ⅱ)/iron oxides in comolex model systems toward contaminant degradation.The effects of common metal ions such as Mn2+,Ca2+,Ni2+,Cr3+and Cu2+,ligands such as small anionic ligands and natural organic matter(NOM),and second metal oxides such as A1,Si and Ti oxides on the redox reactivity of the systems are briefly summarized.
基金This work was supported by the National High-Tech Research and Development Program of China(Grant No.2002AA601260)。
文摘Catalytic wet air oxidation(CWAO)is one of the most promising technologies for pollution abatement.Developing catalysts with high activity and stability is crucial for the application of the CWAO process.The Mn/Ce com-plex oxide catalysts for CWAO of high concentration phenol-containing wastewater were prepared by coprecipitation.The catalyst preparation conditions were optimized by using an orthogonal layout method and single-factor experimental analysis.The Mn/Ce serial catalysts were characterized by Brunauer-Emmett-Teller(BET)analysis and the metal cation leaching was measured by inductively coupled plasma torch-atomic emission spectrometry(ICP-AES).The results show that the catalysts have high catalytic activities even at a low temperature(80°C)and low oxygen partial pressure(0.5 MPa)in a batch reactor.The metallic ion leaching is comparatively low(Mn<6.577 mg/L and Ce<0.6910 mg/L,respectively)in the CWAO process.The phenol,COD_(Cr),and TOC removal efficiencies in the solution exceed 98.5%using the optimal catalyst(named CSP).The new catalyst would have a promising application in CWAO treatment of high concentration organic wastewater.
