(C5H9C5H4)(3)NdBrLi(THF)(4)(1)(C5H9=cyclopentyl) was obtained from the reaction of NdCl3 with C5H9C5H4Na and LiBr (Nd:Na:Li=1:2:1 molar ratio) in THE X-ray crystallography showed that the ten-coordinated neodymium ato...(C5H9C5H4)(3)NdBrLi(THF)(4)(1)(C5H9=cyclopentyl) was obtained from the reaction of NdCl3 with C5H9C5H4Na and LiBr (Nd:Na:Li=1:2:1 molar ratio) in THE X-ray crystallography showed that the ten-coordinated neodymium atom is bonded to three cyclopentylcyclopentadienyl(eta(5)) rings and a single bromine atom bridging a lithium which is bonded to three THF molecules. Complex 1 is triclinic, P1 space group with unit dimensions of a= 12.048(2), b= 13.498(3), c= 13.831(3)Angstrom, a = 104.16(3), beta = 104.07(3), gamma =95.96(3)degrees, V=2083.3(7)Angstrom(3), Z=2, D-c=1.35Mg/m(3) and F(000)=874. (C5H9C5H4)(3)SmTHF (2) was synthesized by reaction of anhydrous SmCl3 with C5H9C5H4Na at a molar ratio of 1:3. The structure was determined by X-ray crystallography. The ten-coordinated samarium atom is bonded to three cycloperrtylcyclopentadienyl rings and one oxygen of THF molecule to form a pseudo-tetrahedron. Complex 2 is orthorhombic, Fdd2 space group with unit cell dimensions of a =28.175(5)Angstrom, b =46.24(2) Angstrom, c =9.167(4) Angstrom(3), V=11943(8)Angstrom(3), Z= 16, D-c = 1.38Mg/m(3) and F(000)=5136.展开更多
Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction(ORR)for the application in low temperature fuel cells and beyond,thus their facile and green synthesis is h...Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction(ORR)for the application in low temperature fuel cells and beyond,thus their facile and green synthesis is highly demanded.Herein we initially report an alternate aqueous phase one-pot synthesis of such catalysts(containing nominally ca.20 wt.%Pt)based on dimethylamine borane(DMAB)reduction.The as-obtained electrocatalyst(denoted as Pt3Co/C-DMAB)is compared with the ones obtained by NaBH4 and N2H4·H2O reduction(denoted as Pt3Co/C-NaBH4 and Pt3Co/C-N2H4·H2O,respectively)as well as a commercial Pt/C,in terms of the structure and electrocatalytic property.It turns out that Pt3Co/C-DMAB exhibits the highest ORR performance among all the tested samples in an O2-saturated 0.1 mol/L HClO4,with the mass activity(specific activity)ca.4(6)times as large as that for Pt/C.After 10000 cycles of the accelerated degradation test,the half-wave potential for ORR on Pt3Co/C-DMAB decreases only by 4 mV,in contrast to 24 mV for that on Pt/C.Pt3Co/C-NaBH4 or Pt3Co/C-N2H4·H2O shows a specific activity comparable to that for Pt3Co/C-DMAB,but a mass activity similar to that for Pt/C.ICP-AES,TEM,XRD and XPS characterizations indicate that Pt3Co nanoparticles are well-dispersed and alloyed with a mean particle size of ca.3.4±0.4 nm,contributing to the prominent electrocatalytic performance of Pt3Co/C-DMAB.This simple aqueous synthetic route may provide an alternate opportunity for developing efficient practical electrocatalysts for ORR.展开更多
The title compound,{[n-Bu_(2)Sn(O_(2)CCH_(2)CS_(2)NC_(4)H_(8))]_(2)O}_(2),has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The co...The title compound,{[n-Bu_(2)Sn(O_(2)CCH_(2)CS_(2)NC_(4)H_(8))]_(2)O}_(2),has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The complex has been characterized by elemental analysis,IR and NMR.The crystal structure of it has been determined by X-ray single crystal diffraction.And the results showed that the crystal belongs to triclinic system with space group P1and some crystal parameters:a=1.2202(9)nm,b=1.3158(10)nm,c=1.3804(10)nm,α=111.215(9)°,β=99.357(9)°,γ=96.075(10)°,V=2.006(2)nm 3,Z=1,F(000)=908,μ=1.489mm^(-1),D c=1.474g·cm^(-3),R_(1)=0.0375,wR_(2)=0.0839.The complex has a centrosymmetric dimer structure mode with a four-membered central endo-cyclic Sn_(2)O_(2)unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom which has a distorted octahedron.Each of the endo-cyclic tin atoms exhibits a distorted trigonal bipyramid coordination geometry with an additional weak coordination carboxylate oxygen.Four carboxylate ligands are divided into two types.And two of them are bidentate and connecting to each of exo-cyclic tin atoms by using both oxygen atoms,whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom only.CCDC:220513.展开更多
Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichlo...Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris(2-chloroethyl)amine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ? b = 105.823(6)? V = 675.7(2) 3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, m(MoKa) = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ? b = 99.505(1)? V = 2383.5(3) ?, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, m(MoKa) = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 (dialdehyde) is located at the crystallographic inversion center nearby the midpoint of C(8)C(8A) single bond. The three chains in the molecule of compound 2 (trialdehyde) are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.展开更多
C50H46OP4ClRh, RhCl(dppm)2 · H2O, Mr = 922. 2, monoclinic, P21/2, a=10. 532(3), b=22.574(8), c=18. 641(8) A, β=93. 41(3)°, V = 4424 (3) A3, Z = 4, Dc=1. 386 g. cm-3, λ(MoKα) = 0. 71073A , F(000) = 1904. T...C50H46OP4ClRh, RhCl(dppm)2 · H2O, Mr = 922. 2, monoclinic, P21/2, a=10. 532(3), b=22.574(8), c=18. 641(8) A, β=93. 41(3)°, V = 4424 (3) A3, Z = 4, Dc=1. 386 g. cm-3, λ(MoKα) = 0. 71073A , F(000) = 1904. The structure was determined by direct methods and difference Fourier syntheses and refined by full-matrix least-squares to final R = 0. 037 and Rw = 0. 036 for 3432 (F> 6. 0σ(F) ) observed reflections. The structure of the title compound contains RhCl-(dppm)2 and non-coordinated H2O molecules. The rhodium atom is coordinated by one chlorine atom and four phosphorus atoms of two DPPM ligands forming a tetragonal pyramidal configuration.展开更多
The lsolobal displacement reaction between the dianion {M(CO)3[(h5-C5H4) C(O)C6H4C(O)(h5-C5H4)](CO)3M}2- and two molecules of [(m3-C)CO2Et]Co3(CO)9 gave rise to the formation of terephthaloyl(biscyclopentadienyl)-brid...The lsolobal displacement reaction between the dianion {M(CO)3[(h5-C5H4) C(O)C6H4C(O)(h5-C5H4)](CO)3M}2- and two molecules of [(m3-C)CO2Et]Co3(CO)9 gave rise to the formation of terephthaloyl(biscyclopentadienyl)-bridged double cluster complexes [(h5-C5H4)C(O)C6H4C(O)(h5-C5H4)]{[(m3-C)CO2Et]Co2M(CO)8}2 (M = Mo 1, M = W, 2). In the reaction, single cluster complexes[(m3-C)CO2Et]-Co2M(CO)8[h5-C5H4C(O)C6H4CO2CH3] ( M = Mo 3, M = W, 4) were yielded as by-products. All the cluster complexes were characterized by C/H analysis, IR and 1H NMR spectroscopy, and the structure of 3 has been determined by single-crystal X-ray diffraction method. Crystal data: Mr = 750.19, monoclinic, space group P21/c, a = 22.652(5), b = 8.954 (2), c = 14.530(3) ? b = 104.00(3), V = 2859.6(10) 懦, Z = 4, Dc = 1.743 mg/m? F(000) = 1488, m = 1.644 mm-1, the final R = 0.0555 and wR = 0.1353 for 5519 observations with I > 2s(I).展开更多
N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The c...N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The crystal of 1 belongs to monoclinic system, space group P21/c with the crystal cell parameters: a = 18.018(6), b = 5.980(2), c = 14.682(5) ? = 109.977(6)? V = 1486.7(9) 3, Z = 4, Dc = 1.449 g/cm3, (MoK? = 2.523 mm-1, F(000) = 664,the final R = 0.0302 and wR = 0.0666 for 2623 independent observed reflections with I > 2(I). Structure analyses revealed that there exist strong nonclassical hydrogen bonds (CH…O).展开更多
Axis House manufactures and supplies alkyl hydroxamate reagent of various carbon chain lengths for application in flotation of oxide copper and other minerals. As a part of reagent performance improvement, the structu...Axis House manufactures and supplies alkyl hydroxamate reagent of various carbon chain lengths for application in flotation of oxide copper and other minerals. As a part of reagent performance improvement, the structural factors of hydroxamate are examined by various analytical tools in particular with X-ray diffraction of single crystals. In a recent publication, the structures of n-octyl hydroxamic acid and its corresponding potassium salt are presented with findings of hydroxamic functional group geometric preference, H-bonding, keto-enol tautomerisation, acid-salt aggregation and alignment of carbon chain. In this paper, an example of branched alkyl hydroxamate3,5,5-trimethyl hexyl hydroxamate. hydroxamate is presented and compared with the result of linear alkyl展开更多
We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five ...We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five treatments and 4 replicates was set up in Qingzhou, Shandong Province, China. In addition to methyl bromide (MB) and untreated control (CK), three alternative fumigation treatments were studied, including MB+VIF (virtually impermeable films), metham sodium (MS) and MS+VIF. Tomato cultivars (Lyeopersicum eseulentum Mill), cv. Maofen-802 were selected as test crops. Results of four fumigations were demonstrated through three-level ten-fold dilution methodology. Abundance of three groups of soil protozoa-flagellates, amoebae, and ciliates was measured from July 2002 to July 2003. Results indicated that two chemical fumigants and their combinations with physical material all significantly repressed soil protozoan abundance. MB was a stronger fumigant than MS, and use of VIF increased their repressive power. The most serious population reduction occurred in amoebae, thus, they also required the longest time to recover. MB and MS also changed the protozoan community structure. MB use decreased the percentage of amoebae but increased percentage of ciliates, while MS incrcased the percentagc of amoebae and decreased the percentage of flagellates in the protozoan community.展开更多
Molecular dynamics simulations have been performed to investigate the structural properties of hydroxyl-substituted alkyl benzenesulfonate monolayers formed at the water/vapor and water/decane interfaces.We report a d...Molecular dynamics simulations have been performed to investigate the structural properties of hydroxyl-substituted alkyl benzenesulfonate monolayers formed at the water/vapor and water/decane interfaces.We report a detailed study of the interfacial properties-liquid density profile,hydrogen bond structure,surfactant aggregate structure and order parameter-of the novel anionic surfactant,sodium 2-hydroxy-3-decyl-5-octylbenzenesulfonate(C10C8OHphSO3Na).Simulation results show that:with increasing number of surfactant molecules,the average number of intramolecular hydrogen bonds per surfactant molecule in the monolayer decreases,but the structures forming the intramolecular hydrogen bonds still play a dominant role;the hydrophobic part of the alkyl tail chain,especially the decyl substituent on the third carbon atom in the benzene ring,becomes straighter,and more ordered towards the external interface at higher surfactant coverage;two-dimensional radial distribution functions can describe the characteristic of surfactant aggregate structures and highlight the decane phase effect on the orientation of the hydrophobic part of the surfactant;the surfactant molecules readily form long-range hydrogen bonded structures.Our results are an important complement to experimental studies.We used the all-atom model by employing the GROMACS and ffAMBER programs in the simulations,which provides a new way to simulate the interfacial behavior of alkyl benzenesulfonate surfactants.展开更多
The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect...The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides(LDHs) on pseudocapacitors. Here, we obtained the CoAl-LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl(DS^-(dodecyl sulfate))-LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g^-1 than CoAl(SO4^2-)-LDH(0.87 nm, 1252.7 F g^-1) and CoAl(CO3^2-)-LDH(0.76 nm, 1149.2 Fg^-1) at a discharge current density of 1 A g^-1. An asymmetric supercapacitor with the CoAl(DS^-)-LDHs‖activated carbon also shows a better electrochemical performance, including a high energy density of54.2 W h kg^-1 at a power density of 0.9 kW kg^-1 and a longterm stability, in comparison with CoAl(SO4^2-)-LDH and CoAl(CO3^2-)-LDH ‖activated carbon.展开更多
The reaction of the alkyl alkylidyne W(CH2CMe3)3(=CSiMe3) (1) with H20 in THF and with D20 in benzene-d6 gave two new trimeric oxo complexes: W3O3(μ=O)3(CH2CMe3)6(THF)3 (2) and [W303(μ=O)3(Ch2CMe3...The reaction of the alkyl alkylidyne W(CH2CMe3)3(=CSiMe3) (1) with H20 in THF and with D20 in benzene-d6 gave two new trimeric oxo complexes: W3O3(μ=O)3(CH2CMe3)6(THF)3 (2) and [W303(μ=O)3(Ch2CMe3)6(D2O)3] 2benzene-d6 (3.2benzened6), respectively, each containing two alkyl ligands per W atom. This is in contrast to the dimer W2o(β-O)(CH2CMe3)6, containing three alkyl ligands per W atom, from the previously reported reaction of the alkyl alkylidyne analog W(CH2CMe3)3- (=-CCMe3) with H2O. In the reaction of 1 with D20 in THF, an unstable intermediate W2O2(μ-O)(CD2SiMe3)2(CH2CMe3)4 (4-d4) was identified. Kinetic studies of the reactions of 1 with excess H2O and D2O in THF-ds, yielding 4 and 4-d4, respectively, give a kinetic isotope effect (KIE) of 3.46(3) at 298(1) K, suggesting that the disappearance of 1 is a rate-determining step.展开更多
文摘(C5H9C5H4)(3)NdBrLi(THF)(4)(1)(C5H9=cyclopentyl) was obtained from the reaction of NdCl3 with C5H9C5H4Na and LiBr (Nd:Na:Li=1:2:1 molar ratio) in THE X-ray crystallography showed that the ten-coordinated neodymium atom is bonded to three cyclopentylcyclopentadienyl(eta(5)) rings and a single bromine atom bridging a lithium which is bonded to three THF molecules. Complex 1 is triclinic, P1 space group with unit dimensions of a= 12.048(2), b= 13.498(3), c= 13.831(3)Angstrom, a = 104.16(3), beta = 104.07(3), gamma =95.96(3)degrees, V=2083.3(7)Angstrom(3), Z=2, D-c=1.35Mg/m(3) and F(000)=874. (C5H9C5H4)(3)SmTHF (2) was synthesized by reaction of anhydrous SmCl3 with C5H9C5H4Na at a molar ratio of 1:3. The structure was determined by X-ray crystallography. The ten-coordinated samarium atom is bonded to three cycloperrtylcyclopentadienyl rings and one oxygen of THF molecule to form a pseudo-tetrahedron. Complex 2 is orthorhombic, Fdd2 space group with unit cell dimensions of a =28.175(5)Angstrom, b =46.24(2) Angstrom, c =9.167(4) Angstrom(3), V=11943(8)Angstrom(3), Z= 16, D-c = 1.38Mg/m(3) and F(000)=5136.
基金supported by the National Basic Research Program of China(973 Program,2015CB932303)the National Natural Science Foundation of China(NSFC)(21733004 and 21473039)the International Cooperation Program of Shanghai Science and Technology Committee(STCSM)(17520711200)~~
文摘Carbon supported Pt-Co alloys are among the most promising electrocatalysts towards oxygen reduction reaction(ORR)for the application in low temperature fuel cells and beyond,thus their facile and green synthesis is highly demanded.Herein we initially report an alternate aqueous phase one-pot synthesis of such catalysts(containing nominally ca.20 wt.%Pt)based on dimethylamine borane(DMAB)reduction.The as-obtained electrocatalyst(denoted as Pt3Co/C-DMAB)is compared with the ones obtained by NaBH4 and N2H4·H2O reduction(denoted as Pt3Co/C-NaBH4 and Pt3Co/C-N2H4·H2O,respectively)as well as a commercial Pt/C,in terms of the structure and electrocatalytic property.It turns out that Pt3Co/C-DMAB exhibits the highest ORR performance among all the tested samples in an O2-saturated 0.1 mol/L HClO4,with the mass activity(specific activity)ca.4(6)times as large as that for Pt/C.After 10000 cycles of the accelerated degradation test,the half-wave potential for ORR on Pt3Co/C-DMAB decreases only by 4 mV,in contrast to 24 mV for that on Pt/C.Pt3Co/C-NaBH4 or Pt3Co/C-N2H4·H2O shows a specific activity comparable to that for Pt3Co/C-DMAB,but a mass activity similar to that for Pt/C.ICP-AES,TEM,XRD and XPS characterizations indicate that Pt3Co nanoparticles are well-dispersed and alloyed with a mean particle size of ca.3.4±0.4 nm,contributing to the prominent electrocatalytic performance of Pt3Co/C-DMAB.This simple aqueous synthetic route may provide an alternate opportunity for developing efficient practical electrocatalysts for ORR.
文摘The title compound,{[n-Bu_(2)Sn(O_(2)CCH_(2)CS_(2)NC_(4)H_(8))]_(2)O}_(2),has been synthesized by the reaction of(tetrahydro-pyrrodithiolocarbamoylthio)acetic acid with the di-n-bubyltin oxide in1∶1molar ratio.The complex has been characterized by elemental analysis,IR and NMR.The crystal structure of it has been determined by X-ray single crystal diffraction.And the results showed that the crystal belongs to triclinic system with space group P1and some crystal parameters:a=1.2202(9)nm,b=1.3158(10)nm,c=1.3804(10)nm,α=111.215(9)°,β=99.357(9)°,γ=96.075(10)°,V=2.006(2)nm 3,Z=1,F(000)=908,μ=1.489mm^(-1),D c=1.474g·cm^(-3),R_(1)=0.0375,wR_(2)=0.0839.The complex has a centrosymmetric dimer structure mode with a four-membered central endo-cyclic Sn_(2)O_(2)unit in which two bridged oxygen atoms both connect with an exo-cyclic tin atom which has a distorted octahedron.Each of the endo-cyclic tin atoms exhibits a distorted trigonal bipyramid coordination geometry with an additional weak coordination carboxylate oxygen.Four carboxylate ligands are divided into two types.And two of them are bidentate and connecting to each of exo-cyclic tin atoms by using both oxygen atoms,whereas the others bridge to each pair of exo-and endo-cyclic tin atoms utilizing one oxygen atom only.CCDC:220513.
基金The authors thank the financial support of the Natural Science Foundation of Fujian Province (No. E0110010)
文摘Two title compounds, 4,4?diformyl-diphenoxyethane (compound 1, C16H14O4) and 4,4?4创-triformyl-triphenoxytriethylamine (compound 2, C27H27NO6), were synthesized by condensation of 4-hydroxybenzaldehyde with 1,2-dichloroethane and tris(2-chloroethyl)amine, respectively in dimethyl formamide in the presence of anhydrous potassium carbonate. The crystal data are: monoclinic, P21/c, a = 7.571(2), b = 12.608(3), c = 7.357(2) ? b = 105.823(6)? V = 675.7(2) 3, Mr = 270.3, Z = 2, Dc = 1.328 g/cm3, F(000) = 284, m(MoKa) = 0.096 mm-1, R = 0.0537 and wR = 0.2189 for compound 1; and monoclinic, P21/n, a = 11.7162(6), b = 9.0042(6), c = 22.908(2) ? b = 99.505(1)? V = 2383.5(3) ?, Mr = 461.50, Z = 4, Dc = 1.286 g/cm3, F(000)= 976, m(MoKa) = 0.091 mm-1, R = 0.0464 and wR = 0.1462 for compound 2. The molecule of compound 1 (dialdehyde) is located at the crystallographic inversion center nearby the midpoint of C(8)C(8A) single bond. The three chains in the molecule of compound 2 (trialdehyde) are of non-crystallographic pseudo-C3 symmetry, and each of them is quite planar.
文摘C50H46OP4ClRh, RhCl(dppm)2 · H2O, Mr = 922. 2, monoclinic, P21/2, a=10. 532(3), b=22.574(8), c=18. 641(8) A, β=93. 41(3)°, V = 4424 (3) A3, Z = 4, Dc=1. 386 g. cm-3, λ(MoKα) = 0. 71073A , F(000) = 1904. The structure was determined by direct methods and difference Fourier syntheses and refined by full-matrix least-squares to final R = 0. 037 and Rw = 0. 036 for 3432 (F> 6. 0σ(F) ) observed reflections. The structure of the title compound contains RhCl-(dppm)2 and non-coordinated H2O molecules. The rhodium atom is coordinated by one chlorine atom and four phosphorus atoms of two DPPM ligands forming a tetragonal pyramidal configuration.
基金This work is supported by Natural Science Foundation of China
文摘The lsolobal displacement reaction between the dianion {M(CO)3[(h5-C5H4) C(O)C6H4C(O)(h5-C5H4)](CO)3M}2- and two molecules of [(m3-C)CO2Et]Co3(CO)9 gave rise to the formation of terephthaloyl(biscyclopentadienyl)-bridged double cluster complexes [(h5-C5H4)C(O)C6H4C(O)(h5-C5H4)]{[(m3-C)CO2Et]Co2M(CO)8}2 (M = Mo 1, M = W, 2). In the reaction, single cluster complexes[(m3-C)CO2Et]-Co2M(CO)8[h5-C5H4C(O)C6H4CO2CH3] ( M = Mo 3, M = W, 4) were yielded as by-products. All the cluster complexes were characterized by C/H analysis, IR and 1H NMR spectroscopy, and the structure of 3 has been determined by single-crystal X-ray diffraction method. Crystal data: Mr = 750.19, monoclinic, space group P21/c, a = 22.652(5), b = 8.954 (2), c = 14.530(3) ? b = 104.00(3), V = 2859.6(10) 懦, Z = 4, Dc = 1.743 mg/m? F(000) = 1488, m = 1.644 mm-1, the final R = 0.0555 and wR = 0.1353 for 5519 observations with I > 2s(I).
基金This work was supported by the NNSFC (No. 29832030)
文摘N-(5-phenylseleno)pentyl succinimide 1, C15H19NO2Se (Mr = 324.27), was prepared by treating Br(CH2)5SePh with potassium succinimide. Its crystal structure has been determined by X-ray single-crystal diffraction. The crystal of 1 belongs to monoclinic system, space group P21/c with the crystal cell parameters: a = 18.018(6), b = 5.980(2), c = 14.682(5) ? = 109.977(6)? V = 1486.7(9) 3, Z = 4, Dc = 1.449 g/cm3, (MoK? = 2.523 mm-1, F(000) = 664,the final R = 0.0302 and wR = 0.0666 for 2623 independent observed reflections with I > 2(I). Structure analyses revealed that there exist strong nonclassical hydrogen bonds (CH…O).
文摘Axis House manufactures and supplies alkyl hydroxamate reagent of various carbon chain lengths for application in flotation of oxide copper and other minerals. As a part of reagent performance improvement, the structural factors of hydroxamate are examined by various analytical tools in particular with X-ray diffraction of single crystals. In a recent publication, the structures of n-octyl hydroxamic acid and its corresponding potassium salt are presented with findings of hydroxamic functional group geometric preference, H-bonding, keto-enol tautomerisation, acid-salt aggregation and alignment of carbon chain. In this paper, an example of branched alkyl hydroxamate3,5,5-trimethyl hexyl hydroxamate. hydroxamate is presented and compared with the result of linear alkyl
文摘We examined soil fumigation effects on soil protozoan abundance and community structure in greenhouses and explored the capacity of protozoa to recover after disturbances. A randomized complete block design with five treatments and 4 replicates was set up in Qingzhou, Shandong Province, China. In addition to methyl bromide (MB) and untreated control (CK), three alternative fumigation treatments were studied, including MB+VIF (virtually impermeable films), metham sodium (MS) and MS+VIF. Tomato cultivars (Lyeopersicum eseulentum Mill), cv. Maofen-802 were selected as test crops. Results of four fumigations were demonstrated through three-level ten-fold dilution methodology. Abundance of three groups of soil protozoa-flagellates, amoebae, and ciliates was measured from July 2002 to July 2003. Results indicated that two chemical fumigants and their combinations with physical material all significantly repressed soil protozoan abundance. MB was a stronger fumigant than MS, and use of VIF increased their repressive power. The most serious population reduction occurred in amoebae, thus, they also required the longest time to recover. MB and MS also changed the protozoan community structure. MB use decreased the percentage of amoebae but increased percentage of ciliates, while MS incrcased the percentagc of amoebae and decreased the percentage of flagellates in the protozoan community.
基金supported by the National Natural Science Foundation of China (21003143)
文摘Molecular dynamics simulations have been performed to investigate the structural properties of hydroxyl-substituted alkyl benzenesulfonate monolayers formed at the water/vapor and water/decane interfaces.We report a detailed study of the interfacial properties-liquid density profile,hydrogen bond structure,surfactant aggregate structure and order parameter-of the novel anionic surfactant,sodium 2-hydroxy-3-decyl-5-octylbenzenesulfonate(C10C8OHphSO3Na).Simulation results show that:with increasing number of surfactant molecules,the average number of intramolecular hydrogen bonds per surfactant molecule in the monolayer decreases,but the structures forming the intramolecular hydrogen bonds still play a dominant role;the hydrophobic part of the alkyl tail chain,especially the decyl substituent on the third carbon atom in the benzene ring,becomes straighter,and more ordered towards the external interface at higher surfactant coverage;two-dimensional radial distribution functions can describe the characteristic of surfactant aggregate structures and highlight the decane phase effect on the orientation of the hydrophobic part of the surfactant;the surfactant molecules readily form long-range hydrogen bonded structures.Our results are an important complement to experimental studies.We used the all-atom model by employing the GROMACS and ffAMBER programs in the simulations,which provides a new way to simulate the interfacial behavior of alkyl benzenesulfonate surfactants.
基金financially supported by the National Natural Science Foundation of China (21501152,21571159,21671178,21441003,51521091 and 51525206)China Postdoctoral Science Foundation (2017M611282)+5 种基金Program for Changjiang Scholars and Innovative Research Team in University (IRT15R61)Ministry of Science and Technology of China (2016YFA0200100 and 2016YBF0100100)Foundation of Zhengzhou University of Light Industry (2014BSJJ054)Strategic Priority Research Program of the Chinese Academy of Sciences (XDA09010104)Projects for Public Entrepreneurship and Public Innovation of ZZULI (2017ZCKJ215)Key Program of Henan Province for Science and Technology (162102210212)
文摘The interlayer space of the layered materials is not always the electrochemical active area for contributing to the pseudocapacitive process. To our knowledge, few efforts have been devoted to investigating the effect of interlayer distance of layered double hydroxides(LDHs) on pseudocapacitors. Here, we obtained the CoAl-LDH with different interlayer distance via the reaction in aqueous media hydrothermally. Electrochemical characterization reveals that the CoAl(DS^-(dodecyl sulfate))-LDHs with an interlayer distance of 2.58 nm can deliver higher specific capacitance of 1481.7 F g^-1 than CoAl(SO4^2-)-LDH(0.87 nm, 1252.7 F g^-1) and CoAl(CO3^2-)-LDH(0.76 nm, 1149.2 Fg^-1) at a discharge current density of 1 A g^-1. An asymmetric supercapacitor with the CoAl(DS^-)-LDHs‖activated carbon also shows a better electrochemical performance, including a high energy density of54.2 W h kg^-1 at a power density of 0.9 kW kg^-1 and a longterm stability, in comparison with CoAl(SO4^2-)-LDH and CoAl(CO3^2-)-LDH ‖activated carbon.
基金supported by the US National Science Foundation(CHE-0749651 & CHE-1012173)
文摘The reaction of the alkyl alkylidyne W(CH2CMe3)3(=CSiMe3) (1) with H20 in THF and with D20 in benzene-d6 gave two new trimeric oxo complexes: W3O3(μ=O)3(CH2CMe3)6(THF)3 (2) and [W303(μ=O)3(Ch2CMe3)6(D2O)3] 2benzene-d6 (3.2benzened6), respectively, each containing two alkyl ligands per W atom. This is in contrast to the dimer W2o(β-O)(CH2CMe3)6, containing three alkyl ligands per W atom, from the previously reported reaction of the alkyl alkylidyne analog W(CH2CMe3)3- (=-CCMe3) with H2O. In the reaction of 1 with D20 in THF, an unstable intermediate W2O2(μ-O)(CD2SiMe3)2(CH2CMe3)4 (4-d4) was identified. Kinetic studies of the reactions of 1 with excess H2O and D2O in THF-ds, yielding 4 and 4-d4, respectively, give a kinetic isotope effect (KIE) of 3.46(3) at 298(1) K, suggesting that the disappearance of 1 is a rate-determining step.