The stable configurations and hydrogen bond nature of （H2O）n clusters （n = 3-6） have been investigated by the B3LYP method at the 6-31＋＋g^＊＊ level. Upon calculation, four conclusions have been drawn： （1） In...The stable configurations and hydrogen bond nature of （H2O）n clusters （n = 3-6） have been investigated by the B3LYP method at the 6-31＋＋g^＊＊ level. Upon calculation, four conclusions have been drawn： （1） In the （H2O）3-5 clusters, cyclic configurations were confirmed to be the most stable. But in the （H2O）3-4 ones, only cyclic configurations could be observed. From n = 5 （（H2O）5 clusters）, three-dimensional configuration could be found： （2） In the （H2O）6 clusters, all configurations are inclined to be three-dimensional except the most stable configuration which is cyclic; （3） The stable order of （H2O）6 clusters indicates that it is the arrangement of hydrogen bond that plays a decisive role in the cluster stabilities, the zero-point energy is also important, and cluster stabilities are independent on the number of hydrogen bonds; （4） There exist strong cooperativity and superadditivity in the （H2O）n clusters.展开更多
Mn(L-Phe)2稨2O]n (Phe=phenylalanine) with a single stranded coordination poly- mer has been synthesized by self-assembly of manganese salt and phenylalanine and characterized by X-ray single-crystal diffraction method...Mn(L-Phe)2稨2O]n (Phe=phenylalanine) with a single stranded coordination poly- mer has been synthesized by self-assembly of manganese salt and phenylalanine and characterized by X-ray single-crystal diffraction method. The complex crystallizes in the orthorhombic, space group P212121 with a = 6.0911(1), b = 10.3642(1), c = 30.4321(7) ? V = 1921.16(6) ?, Z = 4, Dc = 1.387 g/cm3, C18H22N2O5Mn, Mr = 401.32, F(000) = 836 and m(MoKa) = 0.717 mm-1. The final R = 0.0614 and wR = 0.1412 for 2291 observed reflections with I > 2s(I). The magnetic behavior study shows that there exist super-exchange antiferromagnetic interactions between the magnetic centers through the effective exchange pathway of the carboxylate group.展开更多
In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O...In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O,As-N-Na-H2Osystems at ionic mass concentration of0.1mol/kg and temperatures of298,373,423and473K were established according tothermodynamic calculation.The results show that the existence forms of arsenic are associated with pH value,which mainly exists inthe forms of H3AsO4,24H AsO-,24HAsO-,H2AsO2-and As2O3in lower pH region,while it mainly exists in the form of3AsO4-when pH>11.14.High alkali concentration and high temperature are advantageous to the arsenic leaching.The alkaline pressureoxidation leaching experiments display that the tendency of arsenic leaching rate confirms the thermodynamic analysis resultsobtained from theφ-pH diagrams of As-N-Na-H2O system,and the highest leaching rate of arsenic reaches95.85%at453K.展开更多
At room temperature, the reaction of Cd(NO3)24H2O and anisic acid in an ethanol solution affords the cadmium (Ⅱ) complex [Cd(H2O)(CH3OC6H4COO)2]n. The crystal is of monoclinic, empirical formula C16H16O7Cd, Mr = 432....At room temperature, the reaction of Cd(NO3)24H2O and anisic acid in an ethanol solution affords the cadmium (Ⅱ) complex [Cd(H2O)(CH3OC6H4COO)2]n. The crystal is of monoclinic, empirical formula C16H16O7Cd, Mr = 432.69, space group C2/c with parameters: a = 34.211(2), b = 6.030(2), c = 7.611(3) ? = 95.619(5)? V = 1562.5(9) ?, Z = 4, Dc = 1.831 g/cm3, = 1.434 mm-1, F(000) = 856, R = 0.0215 and wR = 0.0456. 1121 reflections with I ≥ 2s(I) were considered to be observed. Each cadmium atom is seven-coordinate in a distorted pentagonal bipyramidal geometry. The Cd (Ⅱ) center is doubly bridged with the neighboring Cd centers by anisate ligands to form a four-membered ring with a repeating unit of CdOCdO-. The extended structure and hydrogen-bonding patterns displayed in the complex were studied.展开更多
A new Cu(Ⅱ) coordination polymer [Cu(inio)2(H2O)] (inio = isonicotinic acid N-oxide) with chemical formula C12H10CuN2O7 was prepared and its crystal structure has been determined by X-ray analysis. The complex crysta...A new Cu(Ⅱ) coordination polymer [Cu(inio)2(H2O)] (inio = isonicotinic acid N-oxide) with chemical formula C12H10CuN2O7 was prepared and its crystal structure has been determined by X-ray analysis. The complex crystallizes in the monoclinic system, space group C2/c with a = 12.455(3), b = 6.202(1), c = 16.555(3) ? b = 106.776(3), V = 1224.3(4) 3, Z = 4, Mr = 357.76, Dc =1.941 g/cm3, m(MoKa) = 1.827 mm-1, F(000) = 724, R = 0.0601 and wR = 0.1417 for 908 observed reflections (I > 2s(I)). The Cu(Ⅱ) atom is coordinated by an elongated square pyramid geometry. The deprotonated isonicotinic acid N-oxides form a double-bridge between each pair of Cu(Ⅱ) ions in trans form through two oxygen atoms from the carboxyl groups and two other oxygen atoms from the -NO groups, respectively, which leads to an infinite one dimensional chain. The two adjacent elongated Cu(Ⅱ) square pyramidal geometries are arranged in trans form in the same chain. The OH…O hydrogen bonds extend the chain structure into two-dimensional layers.展开更多
The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N...The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N＇-bis（salicylidene）ethylenediamine with Cu（OAc）2·H2O results in the formation of Cu（II） complex III. C14H37CoNaO8 （I）： triclinic, space group P1, a = 8.6296（12）, b = 12.0291（17）, c = 12.1108（17） A, α = 75.335（2）, β = 69.991（2）, γ = 72.248（2）°, V= 1109.4（3） A3, Z = 2, ρcaloa = 1.342 g/cm3, the final R= 0.0342 for 4817 observed reflections with I 〉 2σ（I） and Rw = 0.1263 for all data. C6H16N204 （II）： space group P1, a = 5.5513（10）, b = 5.5589（11）, c = 7.4437（14） A, α = 94.332（4）, β = 104.497（4）, γ = 103.487（4）°,V= 214.06（7） A3, Z = 1, ρcalcd = 1.398 g/cm3, the final R = 0.0431 for 829 observed reflections with I〉 2σ（I） and Rw = 0.1263 for all data. C14H37CuN40 （III）, space group P21/n, a = 9.050（9）, b = 18.434（17）, c = 11.659（11） A, β = 107.134（19）°, V= 1859（3） A3, Z = 4, ρcalcd =1.443 g/cm3, the final R = 0.0616 for 3308 observed reflections （O 〉 2σ（I）） and Rw = 0.1229 for all data. Their structures were all determined by X-ray diffraction, elemental analysis and IR.展开更多
The microhydration structure of nickel sulfate aqueous solution has been determined via density functional theory (DFT) calculation and extended X-ray absorption fine structure (EXAFS) spectroscopy.The geometric optim...The microhydration structure of nickel sulfate aqueous solution has been determined via density functional theory (DFT) calculation and extended X-ray absorption fine structure (EXAFS) spectroscopy.The geometric optimization and energy calculation of nickel sulfate hydrated clusters of the molecular formula [NiSO4(H2O)n ]^0 (n=1-12) were determined via DFT using the B3LYP method.Several possible initial structures were considered for clusters of each size to locate the equilibrium geometry.Based on the DFT calculation,the favorable structure of Ni^2+ includes the six-coordinated form of [NiSO4(H2O)n ]^0 clusters.The results of hydration energy calculation suggest that the six-coordinated contact ion pair (CIP) is the stable configuration for small hydration clusters (n≤5),while the solvent-shared ion pair (SSIP) represents the favorable structure for medium hydration clusters (6≤n≤10).The solvent is separated by x water molecules (xSIP,x≥2 is the number of water molecule between Ni^2+ and SO4^2-) in larger hydration clusters (n≥11).The EXAFS analysis of the NiSO 4 aqueous solutions and NiSO4 ·6H2O solid established that Ni^2+ was surrounded by six water molecules tightly forming an octahedral structure in the first hydration shell,and no CIP was found from 0.70 mol/L to 2.22 mol/L (near saturation).The Ni-O distance and coordinated number were 2.040±0.020 and 6.0±1.0,respectively.These results are consistent with the DFT calculations for [NiSO4(H2O)n ]^0 clusters.DFT and EXAFS are powerful techniques that can be used to enhance the resolution of NiSO 4 solution microstructure.展开更多
The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl...The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO2.展开更多
Over the years, there has been a great deal of interest in developing artificial enzymesthat hydrolyse amide bond of peptides and proteins. Recently, we found that Pd(Ⅱ)complexes bind to the sulfur atom of S-methylcy...Over the years, there has been a great deal of interest in developing artificial enzymesthat hydrolyse amide bond of peptides and proteins. Recently, we found that Pd(Ⅱ)complexes bind to the sulfur atom of S-methylcysteine or methionine in peptides andpromote the selective hydrolysis of the adjacent amide bond on the carboxyl side of an-choring side chain. The half-lives of certain hydrolysis reactions are as short as展开更多
基金Project supported by the Natural Science Foundation of Tangshan Teacher’s College (No. 04C06)
文摘The stable configurations and hydrogen bond nature of （H2O）n clusters （n = 3-6） have been investigated by the B3LYP method at the 6-31＋＋g^＊＊ level. Upon calculation, four conclusions have been drawn： （1） In the （H2O）3-5 clusters, cyclic configurations were confirmed to be the most stable. But in the （H2O）3-4 ones, only cyclic configurations could be observed. From n = 5 （（H2O）5 clusters）, three-dimensional configuration could be found： （2） In the （H2O）6 clusters, all configurations are inclined to be three-dimensional except the most stable configuration which is cyclic; （3） The stable order of （H2O）6 clusters indicates that it is the arrangement of hydrogen bond that plays a decisive role in the cluster stabilities, the zero-point energy is also important, and cluster stabilities are independent on the number of hydrogen bonds; （4） There exist strong cooperativity and superadditivity in the （H2O）n clusters.
基金This work was supported by the grants of the National Natural Science Foundation of China the Chinese Academy of Sciences and Hong Kong Polytechnic University (29901005)
文摘Mn(L-Phe)2稨2O]n (Phe=phenylalanine) with a single stranded coordination poly- mer has been synthesized by self-assembly of manganese salt and phenylalanine and characterized by X-ray single-crystal diffraction method. The complex crystallizes in the orthorhombic, space group P212121 with a = 6.0911(1), b = 10.3642(1), c = 30.4321(7) ? V = 1921.16(6) ?, Z = 4, Dc = 1.387 g/cm3, C18H22N2O5Mn, Mr = 401.32, F(000) = 836 and m(MoKa) = 0.717 mm-1. The final R = 0.0614 and wR = 0.1412 for 2291 observed reflections with I > 2s(I). The magnetic behavior study shows that there exist super-exchange antiferromagnetic interactions between the magnetic centers through the effective exchange pathway of the carboxylate group.
基金Project(51564031) supported by the National Natural Science Foundation of ChinaProject(0201352042) supported by the Cooperation between School and Enterprise of China
文摘In order to illustrate the thermodynamic characteristics of arsenic during alkaline pressure oxidation leaching process oflead anode slime(NaNO3as oxidant;NaOH as alkaline reagent),theφ-pH diagrams of As-Na-H2O,N-H2O,As-N-Na-H2Osystems at ionic mass concentration of0.1mol/kg and temperatures of298,373,423and473K were established according tothermodynamic calculation.The results show that the existence forms of arsenic are associated with pH value,which mainly exists inthe forms of H3AsO4,24H AsO-,24HAsO-,H2AsO2-and As2O3in lower pH region,while it mainly exists in the form of3AsO4-when pH>11.14.High alkali concentration and high temperature are advantageous to the arsenic leaching.The alkaline pressureoxidation leaching experiments display that the tendency of arsenic leaching rate confirms the thermodynamic analysis resultsobtained from theφ-pH diagrams of As-N-Na-H2O system,and the highest leaching rate of arsenic reaches95.85%at453K.
基金This work was supported by the National Natural Science Foundation of China (No: 29961002) Natural Science Foundation of Yunnan Province (No: 1999B0003M)
文摘At room temperature, the reaction of Cd(NO3)24H2O and anisic acid in an ethanol solution affords the cadmium (Ⅱ) complex [Cd(H2O)(CH3OC6H4COO)2]n. The crystal is of monoclinic, empirical formula C16H16O7Cd, Mr = 432.69, space group C2/c with parameters: a = 34.211(2), b = 6.030(2), c = 7.611(3) ? = 95.619(5)? V = 1562.5(9) ?, Z = 4, Dc = 1.831 g/cm3, = 1.434 mm-1, F(000) = 856, R = 0.0215 and wR = 0.0456. 1121 reflections with I ≥ 2s(I) were considered to be observed. Each cadmium atom is seven-coordinate in a distorted pentagonal bipyramidal geometry. The Cd (Ⅱ) center is doubly bridged with the neighboring Cd centers by anisate ligands to form a four-membered ring with a repeating unit of CdOCdO-. The extended structure and hydrogen-bonding patterns displayed in the complex were studied.
基金the Natural Science Foundation of Xuzhou Normal University (01BXL009)
文摘A new Cu(Ⅱ) coordination polymer [Cu(inio)2(H2O)] (inio = isonicotinic acid N-oxide) with chemical formula C12H10CuN2O7 was prepared and its crystal structure has been determined by X-ray analysis. The complex crystallizes in the monoclinic system, space group C2/c with a = 12.455(3), b = 6.202(1), c = 16.555(3) ? b = 106.776(3), V = 1224.3(4) 3, Z = 4, Mr = 357.76, Dc =1.941 g/cm3, m(MoKa) = 1.827 mm-1, F(000) = 724, R = 0.0601 and wR = 0.1417 for 908 observed reflections (I > 2s(I)). The Cu(Ⅱ) atom is coordinated by an elongated square pyramid geometry. The deprotonated isonicotinic acid N-oxides form a double-bridge between each pair of Cu(Ⅱ) ions in trans form through two oxygen atoms from the carboxyl groups and two other oxygen atoms from the -NO groups, respectively, which leads to an infinite one dimensional chain. The two adjacent elongated Cu(Ⅱ) square pyramidal geometries are arranged in trans form in the same chain. The OH…O hydrogen bonds extend the chain structure into two-dimensional layers.
文摘The Co（II） complex I and ammonium salt II were synthesized from the direct reaction of 1,2-ethylenediamine and cobaltous acetate tetrahydrate and manganese acetate tetrahydrate in anhydrous ethanol. Treatment of N,N＇-bis（salicylidene）ethylenediamine with Cu（OAc）2·H2O results in the formation of Cu（II） complex III. C14H37CoNaO8 （I）： triclinic, space group P1, a = 8.6296（12）, b = 12.0291（17）, c = 12.1108（17） A, α = 75.335（2）, β = 69.991（2）, γ = 72.248（2）°, V= 1109.4（3） A3, Z = 2, ρcaloa = 1.342 g/cm3, the final R= 0.0342 for 4817 observed reflections with I 〉 2σ（I） and Rw = 0.1263 for all data. C6H16N204 （II）： space group P1, a = 5.5513（10）, b = 5.5589（11）, c = 7.4437（14） A, α = 94.332（4）, β = 104.497（4）, γ = 103.487（4）°,V= 214.06（7） A3, Z = 1, ρcalcd = 1.398 g/cm3, the final R = 0.0431 for 829 observed reflections with I〉 2σ（I） and Rw = 0.1263 for all data. C14H37CuN40 （III）, space group P21/n, a = 9.050（9）, b = 18.434（17）, c = 11.659（11） A, β = 107.134（19）°, V= 1859（3） A3, Z = 4, ρcalcd =1.443 g/cm3, the final R = 0.0616 for 3308 observed reflections （O 〉 2σ（I）） and Rw = 0.1229 for all data. Their structures were all determined by X-ray diffraction, elemental analysis and IR.
基金Nature Science Foundation of Qinghai Province(2018-ZJ-945Q)NSFC(21573268)+1 种基金Joint Foundation of Salt Lake Chemical(U1607106)Instrument function development and technology innovation project of Chinese academy of sciences(2018g108)
文摘The microhydration structure of nickel sulfate aqueous solution has been determined via density functional theory (DFT) calculation and extended X-ray absorption fine structure (EXAFS) spectroscopy.The geometric optimization and energy calculation of nickel sulfate hydrated clusters of the molecular formula [NiSO4(H2O)n ]^0 (n=1-12) were determined via DFT using the B3LYP method.Several possible initial structures were considered for clusters of each size to locate the equilibrium geometry.Based on the DFT calculation,the favorable structure of Ni^2+ includes the six-coordinated form of [NiSO4(H2O)n ]^0 clusters.The results of hydration energy calculation suggest that the six-coordinated contact ion pair (CIP) is the stable configuration for small hydration clusters (n≤5),while the solvent-shared ion pair (SSIP) represents the favorable structure for medium hydration clusters (6≤n≤10).The solvent is separated by x water molecules (xSIP,x≥2 is the number of water molecule between Ni^2+ and SO4^2-) in larger hydration clusters (n≥11).The EXAFS analysis of the NiSO 4 aqueous solutions and NiSO4 ·6H2O solid established that Ni^2+ was surrounded by six water molecules tightly forming an octahedral structure in the first hydration shell,and no CIP was found from 0.70 mol/L to 2.22 mol/L (near saturation).The Ni-O distance and coordinated number were 2.040±0.020 and 6.0±1.0,respectively.These results are consistent with the DFT calculations for [NiSO4(H2O)n ]^0 clusters.DFT and EXAFS are powerful techniques that can be used to enhance the resolution of NiSO 4 solution microstructure.
基金supported by the Doctoral Fund of Ministry of Education of China(No.20070141046)the Fund of Education Department of Liaoning Province(No.[2006]124)
文摘The promoting effect of ethanol on the synthesis of N-（2-methylphenyl）hydroxylamine from o-nitrotoluene in Zn/H2O/CO2 system was observed.By adding appropriate amount of ethanol,the selectivity of N-（2-methylphenyl）hydroxylamine increased from 71%to 90%when the reduction was carried out at 25℃under normal pressure of CO2.
基金Project supported by the National Natural Science Foundation of China.
文摘Over the years, there has been a great deal of interest in developing artificial enzymesthat hydrolyse amide bond of peptides and proteins. Recently, we found that Pd(Ⅱ)complexes bind to the sulfur atom of S-methylcysteine or methionine in peptides andpromote the selective hydrolysis of the adjacent amide bond on the carboxyl side of an-choring side chain. The half-lives of certain hydrolysis reactions are as short as
