One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = ...One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = 2.3475(5), b = 1.2208(2), c = 1.9499(4) nm, β= 114.682(3)°, V = 5.0778(16) nm^3, Dc = 1.339 g/cm^3, Z = 4,μ(MoKa) = 0.458 mm^-1, F(000) = 2168, GOOF = 1.014, R = 0.0401 and wR = 0.0961. The nickel(H) center in the title complex is coordinated with six nitrogen atoms of three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. However, the nickel(Ⅱ) ion does not coordinate to the hexane dicarboxylic acid. The complex molecules form a 3D structure through hydrogen bonds. TG analysis shows that the title complex is stable below 240.0 ℃.展开更多
A new complex has been synthesized with o-methylbenzoyl-benzoic acid(HL) and 1,10-phenanthroline(phen) in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328(18), b...A new complex has been synthesized with o-methylbenzoyl-benzoic acid(HL) and 1,10-phenanthroline(phen) in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328(18), b = 17.7876(18), c = 19.998(2), β = 104.720(4)o, C54H48N4O11Zn, Mr = 994.33, V = 4690.2(9)3, Dc = 1.408 g/cm3, Z = 4, F(000) = 2072, μ(MoKα) = 0.59 mm-1, R = 0.0736 and wR = 0.2029. The crystal structure shows that the zinc ions are coordinated with two oxygen atoms from two HL molecules and four nitrogen atoms from two phen molecules, forming distorted octahedral coordination geometry. The fluorescent and thermal stability properties of the complex are studied. The result shows that it has one fluorescent emission band at around 412 nm. In addition, the complex is stable under 210 ℃.展开更多
A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic...A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.展开更多
A new dinuclear copper(II) complex [Cu2(L)2(phen)2]·5H2O (1) with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid (H2L) and 1,10-phenanthroline (phen) as ligands has been synthesized in the mixed sol...A new dinuclear copper(II) complex [Cu2(L)2(phen)2]·5H2O (1) with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid (H2L) and 1,10-phenanthroline (phen) as ligands has been synthesized in the mixed solvents of ethanol and water. It crystallizes in the monoclinic space group P21/c, with a = 17.925(4), b = 19.908(4), c = 11.235(2) A, β = 97.65(3)°, V= 3973.4(14) A3, Dc = 1.552 g/cm^3, Z = 8, F(000) = 1910, the final GOOF = 1.056, R= 0.0519 and wR= 0.1293. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two copper ions are bridged by twoμ2-η1 :η0-3-carboxylate groups of L^2- anions. The fluorescence and thermal stability properties of 1 were studied. The results show that 1 has an intense fluorescent emission at around 381 rim. The TG analysis shows that I is stable below 143 ℃.展开更多
A new dinuclear manganese complex [Mn2(L)2(2,2'-bipy)2(H2O)512·3H2O has been synthesized with MnSO4·H2O, 2,2'-bibenzoic acid (H2L) and 2,2'-bipyridine(2,2'-bipy) in the mixed solvent ethanol an...A new dinuclear manganese complex [Mn2(L)2(2,2'-bipy)2(H2O)512·3H2O has been synthesized with MnSO4·H2O, 2,2'-bibenzoic acid (H2L) and 2,2'-bipyridine(2,2'-bipy) in the mixed solvent ethanol and water. It crystallizes in monoclinic, space group Pi with a = 9.9944(10), b = 21.939(2), c = 25.628(3) A, a = 108.429(3), β = 100.613(4), 7 = 102.821(3)°, V = 4997.9(9) A3, Dc= 1.355 g/cm^3, Z = 2, F(000) = 2108, GOOF = 1.074, the R= 0.0626 and wR= 0.1531. The structure of the complex contains two [Mn2(L)2(2,2'-bipy)2] units, ten coordinated H2O molecules and three uncoordinated H2O molecules. The fluorescence, thermal stability and magnetic properties of the complex were investigated.展开更多
A new dinuclear copper(Ⅱ) complex [Cu(CH3COO)(C7H5N4)(H2O)]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallize...A new dinuclear copper(Ⅱ) complex [Cu(CH3COO)(C7H5N4)(H2O)]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallizes in the monoclinic space group P21/c, with a = 12.0188(7), b = 13.7993(8), c = 8.7488(5) A, β = 101.7350(10)o, V = 1420.67(14) A3, D3 c = 1.568 g/cm, Z = 1, F(000) = 690, the final GOOF = 1.145, R = 0.0437, and w R = 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ2-η1:η0 3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Cu(Ⅱ) ion is Cu O2N3, giving a distorted square pyramidal geometry. The thermal stability and magnetic properties of the complex were investigated.展开更多
A new 1D chain copper coordination polymer [CuE(H2L)2(C10HsN2)(HEO)2]n'3n(H20) with 2,3-pyridinedi carboxylic acid (H2L) and 2,2'-bipyridine (2,2'-bipy) as ligands has been synthesized in the mixed etha...A new 1D chain copper coordination polymer [CuE(H2L)2(C10HsN2)(HEO)2]n'3n(H20) with 2,3-pyridinedi carboxylic acid (H2L) and 2,2'-bipyridine (2,2'-bipy) as ligands has been synthesized in the mixed ethanol and water solvents. Crystal data for this complex are as follows: monoclinic, space group P2Jc, a = 7.7713(7), b = 27.478(3), c = 13.2621(13)/1,, fl = 100.6940(10), V= 2782.8(5) A3, Dc = 1.722 g/cm3, Z = 4, p = 1.61 mm-1, F(000) = 1472, the final R = 0.0363 and wR = 0.0933. In the crystal structure, the whole molecule consists of two cooper ions, two H2L, one 2,2"-bipy molecule and six water molecules. Each central copper ion is coordinated with three oxygen atoms from two H2L and one water molecule, two nitrogen atoms from one 2,2'-bipy molecule and two H2L, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.展开更多
A new nickel(Ⅱ) complex Ni2(L)2(2,2'-bipy)2·5.5H2O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2'-bipy) as ligands has been synthesized in the mixed solvent ...A new nickel(Ⅱ) complex Ni2(L)2(2,2'-bipy)2·5.5H2O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2'-bipy) as ligands has been synthesized in the mixed solvent DMF and water(v:v = 5:2). It crystallizes in the triclinic space group P1 with a = 10.414(2), b = 12.884(3), c = 16.176(4) A, α = 70.715(5), β = 80.599(5), γ = 77.383(6)°, V = 1989.4(8) A^3, Dc = 1.531 g/cm^3, Z = 2, F(000) = 958, GOOF = 1.028, the final R = 0.0808 and w R = 0.2036. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two nickel ions are bridged by two μ2-η1:η0 3-carboxylate groups of L2- anions. The coordination environment of Ni(Ⅱ) ion is Ni N2O3, giving a distorted square pyramidal geometry. The thermal stability and electrochemical properties of the complex were investigated.展开更多
To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into(Pr(0.25)Nd(0.75))(30.6)Cu(0.15)Fe(bal)B1(wt.%) b...To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into(Pr(0.25)Nd(0.75))(30.6)Cu(0.15)Fe(bal)B1(wt.%) basic magnets. The effects of the addition of terbium sulfide on magnetic properties, microstructure, and thermal stability of sintered Nd–Fe–B magnets are investigated.The experimental results show that by adding 3 wt.% Tb2S3, the coercivity of the magnet is remarkably increased by about 54% without a considerable reduction in remanence and maximum energy product. By means of the electron probe microanalyzer(EPMA) technology, it is observed that Tb is mainly present in the outer region of 2:14:1 matrix grains and forms a well-developed Tb-shell phase, resulting in enhancement of HA, which accounts for the coercivity enhancement.Moreover, compared with Tb2S3-free magnets, the reversible temperature coefficients of remanence(α) and coercivity(β) and the irreversible flux loss of magnetic flow(hirr) values of Tb2S3-added magnets are improved, indicating that the thermal stability of the magnets is also effectively improved.展开更多
One new cobalt complex [Co(phen)3][(C6Hs)2C(OH)COO]2·7H2O with benzeneacetic acid (BAA), 1,10-phenanthroline and cobaltous perchlorate has been synthesized by means of solvent method. It crystallizes in t...One new cobalt complex [Co(phen)3][(C6Hs)2C(OH)COO]2·7H2O with benzeneacetic acid (BAA), 1,10-phenanthroline and cobaltous perchlorate has been synthesized by means of solvent method. It crystallizes in the triclinic system, space group P^-1, with a = 1.14181(13), b = 1.64417(18), c = 1.65342(18) nm, α = 74.2830(10), β= 84.4490(10), γ = 74.9430(10)°, V = 2.8842(6) nm^3, Dc = 1.359 g/cm^3, Z = 2, F(000) = 1234, R = 0.0621 and wR = 0.1673. The crystal structure shows that the cobalt ion is coordinated with six nitrogen atoms from three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. There are a lot of hydrogen bonds in the complex, from which a two-dimensional network is constructed. The result of TG analysis shows that the title complex is stable below 130.0 ℃.展开更多
Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic pr...Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic properties for the Pr0.85La0.15Co4.3 and Pr0.75La0.25Co4.1 magnets are iHc=368 kA/m, Br=0.91 T, (BH)max=145.6 kJ/m3, αBr=-0.03%/℃ and iHc=568 kA/m,Br=0.8 T, (BH)max=127.2 kJ/m3,αBr,=-0.06%/℃, respectively The phase structures of as-cast alloys and magnets were investigated展开更多
A new zinc coordination polymer{[Zn2(ttmb)2(dca)4(H2O)].H2O}n(1.H2O)was synthesized by the reaction of 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene(ttmb),Zn(Ⅱ)salt and sodium dicyanamide(Na(dca)).The structure of the ...A new zinc coordination polymer{[Zn2(ttmb)2(dca)4(H2O)].H2O}n(1.H2O)was synthesized by the reaction of 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene(ttmb),Zn(Ⅱ)salt and sodium dicyanamide(Na(dca)).The structure of the title compound was determined by single-crystal X-ray diffraction,elemental analyses and IR spectra.1 exhibits a(3,4)-connected 2D double-layer network with the point symbol of{63}{(66}.The solid-state luminescence shows a strong emission band at 485 nm upon excitation at 384 nm.The thermal stability properties were also studied.展开更多
This paper reports crystal structures, magnetic properties and thermal stability of TbCu7-type Sm(8.5)Fe((85.8-x)Co(4.5)Zr(1.2)Nbx(x = 0-1.8) melt-spun compounds and their nitrides, investigated by means of...This paper reports crystal structures, magnetic properties and thermal stability of TbCu7-type Sm(8.5)Fe((85.8-x)Co(4.5)Zr(1.2)Nbx(x = 0-1.8) melt-spun compounds and their nitrides, investigated by means of X-ray diffraction, vibrating sample magnetometer, flux meter and transmission electron microscope. It is found that the lattice parameter ratio c/a of TbCu7-type crystal structure increases with Nb substitution, which indicates that the Nb can increase the stability of the metastable phase in the Sm-Fe ribbons. Nb substitution impedes the formation of magnetic soft phase a-Fe in which reversed domains initially form during the magnetization reversal process. Meanwhile, Nb substitution refines grains and leads to homogeneous micro structure with augmented grain boundaries. Thus the exchange coupling pining field is enhanced and irreversible domain wall propagation gets suppressed. As a result, the magnetic properties are improved and the irreversible flux loss of magnets is notably decreased. A maximum value 771.7 kA/m of the intrinsic coercivity H(cj) is achieved in the 1.2 at% substituted samples.The irreversible flux loss for 2 h exposure at 120 ℃ declines from 8.26% for Nb-free magnets to 6.32% for magnets with 1.2 at% Nb substitution.展开更多
To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber(LSR), a series of modified LSR samples were prepared by introducing octavinyl-p...To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber(LSR), a series of modified LSR samples were prepared by introducing octavinyl-polyhedral oligosilsesquioxanes(VPOSS) and high purity silicon sol singly or in combination before vulcanization. Significant correlation was found between the loading rate of VPOSS and thermal properties. However, mechanical properties were negatively correlated with VPOSS content within the range experimented, which may be ascribed to material defect caused by uneven distribution and aggregation. Furthermore, test results approved that the introducing of silicon sol indeed affected the stabilities of the polymer by restraining the material defect caused by the aggregation of POSS molecules and improving cross link density. For example, adding 10%-20% of silicon sol into VPOSS(1.0%) modified LSR will increase tear resistance by 43.9%-85.7%, elongation at break by 31.7%-57.3%, residue at 800 ℃ in N2 atmosphere by 32.0%-37.9%, residue at 650 ℃ in air atmosphere by 70.9%-91.6%, respectively. This work proves that, to incorporate VPOSS into LSR by hydrosilylation, and to use silicon sol as dispersant and reinforce filler can become an efficient way to improve the mechanical property, thermal stability and bio-compatibility of LSR in the future.展开更多
The effect of Ga_2O_3 on the structure and properties of calcium aluminate glasses fabricated by vacuum melting process was investigated by Raman spectrum, differential scanning calorimeter(DSC), and infrared spectr...The effect of Ga_2O_3 on the structure and properties of calcium aluminate glasses fabricated by vacuum melting process was investigated by Raman spectrum, differential scanning calorimeter(DSC), and infrared spectrum methods. The results show that calcium aluminate glass network only consists of [AlO_4] tetrahedral units. With the gradual addition of Ga_2O_3, the quantity of [GaO_4] tetrahedral units increases. Substitution of Ga_2O_3 for Al_2O_3 results in a decrease in Tg, Tx, and Tp, and an increase in the thermal stable index ΔT. Similarly, the absorption band around 3.0 μm obviously reduces and the transparency in 4.0-6.0 μm rapidly increases with increasing Ga_2O_3 content. However, the chemical stability of calcium aluminate glasses decreases if Ga_2O_3 is introduced due to the increasing of [GaO_4] units in the glass network.展开更多
The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior...The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior (temperature-programmed reduction/temperatureprogrammed re-oxidation) as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 (υ1) and 650 cm-1 (υ2) respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts.展开更多
A new Sr(Ⅱ) complex, [Sr(Hsip)(H2O)] (1, NaH2sip = 5-sulfoisophthalic acid monosodium), has been synthesized by solvothermal reaction of SrCO3 and NaH2sip at 120 ℃, and characterized by single-crystal X-ray ...A new Sr(Ⅱ) complex, [Sr(Hsip)(H2O)] (1, NaH2sip = 5-sulfoisophthalic acid monosodium), has been synthesized by solvothermal reaction of SrCO3 and NaH2sip at 120 ℃, and characterized by single-crystal X-ray diffraction studies, elemental analysis and FT-IR. Single- crystal X-ray diffraction reveals that compound 1 has a 3D architecture, and there is only one crystallographically independent Sr(Ⅱ) ion in 1. The coordination geometry of Sr(Ⅱ) is a distorted tetragonai anti-prism. The whole Hsip2- ligand performs aμ6-coordination model. In the solid state, complex 1 shows luminescence with the maximum emission intensity at 417 nm upon excitation at 320 nm. Thermal stability of complex 1 was also investigated.展开更多
Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,w...Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.展开更多
Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction(XRD), thermal magnetic analysis(TMA), and magnetic measurements. XRD results show that all ...Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction(XRD), thermal magnetic analysis(TMA), and magnetic measurements. XRD results show that all the compounds have a main phase of hexagonal CaCu5-type crystal structure with small amount of impurity phases; increasing Tm content is associated with contraction of the hexagonal unit cell in the direction of the c axis and expansion of the a and b parameters. TMA results indicate that the Curie temperature(TC) of Sm1-xTmxCo5 compounds gets higher with the increase in Tm content.Magnetic measurements show that both the magnetic anisotropy field(HA) and the magnetization at an applied field of 7 T(M7 T) decrease with the increase of Tm content. However, the thermal stability of both the HAand M7 Tof all the Tm doped compounds is remarkably improved compared with that of the pure SmCo5 compound, leading to the result that both the M7 Tand HAof Sm0.8Tm0.2Co5 .2are higher than those of SmCo5 compound at 473 K, which indicates the good potential of Tm doped compound in the practical applications at elevated temperature.展开更多
The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by i...The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis(TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction(WAXD) and scanning electron microscope(SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin.展开更多
基金Project supported by the Fund of Science and Technology Committee of Hunan Province (2008FJ3023)the Research Award Fund for Outstanding Young Teachers of Hengyang Normal University (2006)Key Subject Fund of Hunan Province
文摘One novel complex [Ni(phen)3],(C8H12O4)·(H2O)14 with hexane dicarboxylic acid and 1,10-phenanthroline has been hydrothermally synthesized and characterized. Crystal data: monoclinic, space group C2/c, a = 2.3475(5), b = 1.2208(2), c = 1.9499(4) nm, β= 114.682(3)°, V = 5.0778(16) nm^3, Dc = 1.339 g/cm^3, Z = 4,μ(MoKa) = 0.458 mm^-1, F(000) = 2168, GOOF = 1.014, R = 0.0401 and wR = 0.0961. The nickel(H) center in the title complex is coordinated with six nitrogen atoms of three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. However, the nickel(Ⅱ) ion does not coordinate to the hexane dicarboxylic acid. The complex molecules form a 3D structure through hydrogen bonds. TG analysis shows that the title complex is stable below 240.0 ℃.
基金Supported by the Natural Science Foundation of Hunan Province(No.11JJ9006)Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)the Construct Program of the Key Discipline in Hunan Province
文摘A new complex has been synthesized with o-methylbenzoyl-benzoic acid(HL) and 1,10-phenanthroline(phen) in the mixture of water and ethanol. It crystallizes in monoclinic, space group C2/c with a = 13.6328(18), b = 17.7876(18), c = 19.998(2), β = 104.720(4)o, C54H48N4O11Zn, Mr = 994.33, V = 4690.2(9)3, Dc = 1.408 g/cm3, Z = 4, F(000) = 2072, μ(MoKα) = 0.59 mm-1, R = 0.0736 and wR = 0.2029. The crystal structure shows that the zinc ions are coordinated with two oxygen atoms from two HL molecules and four nitrogen atoms from two phen molecules, forming distorted octahedral coordination geometry. The fluorescent and thermal stability properties of the complex are studied. The result shows that it has one fluorescent emission band at around 412 nm. In addition, the complex is stable under 210 ℃.
基金Supported by the Natural Science Foundation of Hunan Province (No. 11JJ9006)Key Project of Science and Technology Plan of Hunan Province (2012FJ2002)+1 种基金Science and Technology Plan of Hunan Province (2012GK3031, 2012WK3029)the Construct Program of Key Discipline in Hunan Province
文摘A new complex Cu2(o-C6H5COC6H5COO)4(C10H8N2)2(H2O)2 with 2-benzoylben- zoic acid and 2,2′-bipyridine as ligands has been synthesized in mixed methanol and water solvent. Crystal data are as follows: monoclinic, space group Co, a = 14.0133(14), b = 16.0409(16), c = 30.372(3) A, β = 100.8950(10)°, V = 6704.1(12) A3, Dc = 1.364 g/cm3, Z = 8,μ(MoKa) = 0.704 mml, F(000) = 2840, the final R= 0.0552 and wR = 0.1431. In the crystal structure, the whole molecule consists of two copper ions, four 2-benzoylbenzoic acid molecules, two 2,2′-bipyridine molecules and two water molecules. Each central copper ion is coordinated with two nitrogen atoms from one 2,2′-bipyridine molecule and three oxygen atoms from two 2-benzoylbenzoic acids and one water molecule, respectively, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.
基金Supported by the Construct Program of the Key Discipline in Hunan Province and Key Project of Production Plan of Hengyang City(2013)
文摘A new dinuclear copper(II) complex [Cu2(L)2(phen)2]·5H2O (1) with bicycle[2.2.1 ]hept- 2-en-5, 6-dicarboxylic acid (H2L) and 1,10-phenanthroline (phen) as ligands has been synthesized in the mixed solvents of ethanol and water. It crystallizes in the monoclinic space group P21/c, with a = 17.925(4), b = 19.908(4), c = 11.235(2) A, β = 97.65(3)°, V= 3973.4(14) A3, Dc = 1.552 g/cm^3, Z = 8, F(000) = 1910, the final GOOF = 1.056, R= 0.0519 and wR= 0.1293. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two copper ions are bridged by twoμ2-η1 :η0-3-carboxylate groups of L^2- anions. The fluorescence and thermal stability properties of 1 were studied. The results show that 1 has an intense fluorescent emission at around 381 rim. The TG analysis shows that I is stable below 143 ℃.
基金Supported by the Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)Science and Technology Committee of Hengyang(2013KG77)the Construct Program of the Key Discipline in Hunan Province
文摘A new dinuclear manganese complex [Mn2(L)2(2,2'-bipy)2(H2O)512·3H2O has been synthesized with MnSO4·H2O, 2,2'-bibenzoic acid (H2L) and 2,2'-bipyridine(2,2'-bipy) in the mixed solvent ethanol and water. It crystallizes in monoclinic, space group Pi with a = 9.9944(10), b = 21.939(2), c = 25.628(3) A, a = 108.429(3), β = 100.613(4), 7 = 102.821(3)°, V = 4997.9(9) A3, Dc= 1.355 g/cm^3, Z = 2, F(000) = 2108, GOOF = 1.074, the R= 0.0626 and wR= 0.1531. The structure of the complex contains two [Mn2(L)2(2,2'-bipy)2] units, ten coordinated H2O molecules and three uncoordinated H2O molecules. The fluorescence, thermal stability and magnetic properties of the complex were investigated.
基金Supported by the Construct Program of the Key Discipline in Hunan Province and Key Project of Production Plan of Hengyang City(2013)
文摘A new dinuclear copper(Ⅱ) complex [Cu(CH3COO)(C7H5N4)(H2O)]2·3.5H2 O has been hydrothermally synthesized with copper acetate, o-acetamidobenzoic acid and 3-(pyridin-2-yl)-1,2,4-triazole. It crystallizes in the monoclinic space group P21/c, with a = 12.0188(7), b = 13.7993(8), c = 8.7488(5) A, β = 101.7350(10)o, V = 1420.67(14) A3, D3 c = 1.568 g/cm, Z = 1, F(000) = 690, the final GOOF = 1.145, R = 0.0437, and w R = 0.1097. The crystal structure shows that the whole molecule consists of two copper ions bridged by two μ2-η1:η0 3-(pyridin-2-yl)-1,2,4-triazole anions. The coordination environment of Cu(Ⅱ) ion is Cu O2N3, giving a distorted square pyramidal geometry. The thermal stability and magnetic properties of the complex were investigated.
基金Supported by the Natural Science Foundation of Hunan Province(No.11JJ9006)Key Project of Science and Technology Plan of Hunan Province(2012FJ2002)+1 种基金Science and Technology Plan of Hunan Province(2012GK3031,2012WK3029)the Construct Program of the Key Discipline in Hunan Province
文摘A new 1D chain copper coordination polymer [CuE(H2L)2(C10HsN2)(HEO)2]n'3n(H20) with 2,3-pyridinedi carboxylic acid (H2L) and 2,2'-bipyridine (2,2'-bipy) as ligands has been synthesized in the mixed ethanol and water solvents. Crystal data for this complex are as follows: monoclinic, space group P2Jc, a = 7.7713(7), b = 27.478(3), c = 13.2621(13)/1,, fl = 100.6940(10), V= 2782.8(5) A3, Dc = 1.722 g/cm3, Z = 4, p = 1.61 mm-1, F(000) = 1472, the final R = 0.0363 and wR = 0.0933. In the crystal structure, the whole molecule consists of two cooper ions, two H2L, one 2,2"-bipy molecule and six water molecules. Each central copper ion is coordinated with three oxygen atoms from two H2L and one water molecule, two nitrogen atoms from one 2,2'-bipy molecule and two H2L, giving a distorted tetragonal pyramidal geometry. Thermal stability properties of the complex were investigated.
基金Supported by the Construct Program of the Key Discipline in Hunan ProvinceKey Project of Industrial Science and Technology Support of Hengyang City(2015KG23)
文摘A new nickel(Ⅱ) complex Ni2(L)2(2,2'-bipy)2·5.5H2O with methy-bicycle[2.2.1]hept-5-ene-2,3-dicarboxylic acid(H2L) and 2,2?-bipyridine(2,2'-bipy) as ligands has been synthesized in the mixed solvent DMF and water(v:v = 5:2). It crystallizes in the triclinic space group P1 with a = 10.414(2), b = 12.884(3), c = 16.176(4) A, α = 70.715(5), β = 80.599(5), γ = 77.383(6)°, V = 1989.4(8) A^3, Dc = 1.531 g/cm^3, Z = 2, F(000) = 958, GOOF = 1.028, the final R = 0.0808 and w R = 0.2036. The crystal structure shows that the whole molecule consists of two independent dinuclear units, in which two nickel ions are bridged by two μ2-η1:η0 3-carboxylate groups of L2- anions. The coordination environment of Ni(Ⅱ) ion is Ni N2O3, giving a distorted square pyramidal geometry. The thermal stability and electrochemical properties of the complex were investigated.
基金Project supported by the Science Funds from the Ministry of Science and Technology,China(Grant Nos.2014DFB50130 and 2011CB612304)the National Natural Science Foundation of China(Grant Nos.51172168 and 51072139)
文摘To increase coercivity and thermal stability of sintered Nd–Fe–B magnets for high-temperature applications, a novel terbium sulfide powder is added into(Pr(0.25)Nd(0.75))(30.6)Cu(0.15)Fe(bal)B1(wt.%) basic magnets. The effects of the addition of terbium sulfide on magnetic properties, microstructure, and thermal stability of sintered Nd–Fe–B magnets are investigated.The experimental results show that by adding 3 wt.% Tb2S3, the coercivity of the magnet is remarkably increased by about 54% without a considerable reduction in remanence and maximum energy product. By means of the electron probe microanalyzer(EPMA) technology, it is observed that Tb is mainly present in the outer region of 2:14:1 matrix grains and forms a well-developed Tb-shell phase, resulting in enhancement of HA, which accounts for the coercivity enhancement.Moreover, compared with Tb2S3-free magnets, the reversible temperature coefficients of remanence(α) and coercivity(β) and the irreversible flux loss of magnetic flow(hirr) values of Tb2S3-added magnets are improved, indicating that the thermal stability of the magnets is also effectively improved.
基金Supported by the Fund of Science and Technology Committee of Hunan Province (2007SK4012)The Construct Program of the Key Disipline in Hunan Province
文摘One new cobalt complex [Co(phen)3][(C6Hs)2C(OH)COO]2·7H2O with benzeneacetic acid (BAA), 1,10-phenanthroline and cobaltous perchlorate has been synthesized by means of solvent method. It crystallizes in the triclinic system, space group P^-1, with a = 1.14181(13), b = 1.64417(18), c = 1.65342(18) nm, α = 74.2830(10), β= 84.4490(10), γ = 74.9430(10)°, V = 2.8842(6) nm^3, Dc = 1.359 g/cm^3, Z = 2, F(000) = 1234, R = 0.0621 and wR = 0.1673. The crystal structure shows that the cobalt ion is coordinated with six nitrogen atoms from three 1,10-phenanthroline molecules, giving a distorted octahedral coordination geometry. There are a lot of hydrogen bonds in the complex, from which a two-dimensional network is constructed. The result of TG analysis shows that the title complex is stable below 130.0 ℃.
文摘Pr1-xLaxCo5-y (x=0, 0.15. 0.25, 0.35,1.0, y=0.5, 0.7, 0.9, 1.0) alloys were investigated. The effect of the variation of x and y on magnetic properties and thermal stability of the alloys were studied. The magnetic properties for the Pr0.85La0.15Co4.3 and Pr0.75La0.25Co4.1 magnets are iHc=368 kA/m, Br=0.91 T, (BH)max=145.6 kJ/m3, αBr=-0.03%/℃ and iHc=568 kA/m,Br=0.8 T, (BH)max=127.2 kJ/m3,αBr,=-0.06%/℃, respectively The phase structures of as-cast alloys and magnets were investigated
基金the Natural Science Foundation of Jiangsu Province(No.BK20161212)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe project of Scientific and Technological Infrastructure of Suzhou(SZS201905)。
文摘A new zinc coordination polymer{[Zn2(ttmb)2(dca)4(H2O)].H2O}n(1.H2O)was synthesized by the reaction of 1,3,5-tris(1,2,4-triazol-1-ylmethyl)benzene(ttmb),Zn(Ⅱ)salt and sodium dicyanamide(Na(dca)).The structure of the title compound was determined by single-crystal X-ray diffraction,elemental analyses and IR spectra.1 exhibits a(3,4)-connected 2D double-layer network with the point symbol of{63}{(66}.The solid-state luminescence shows a strong emission band at 485 nm upon excitation at 384 nm.The thermal stability properties were also studied.
基金Project supported by the National Natural Science Foundation of China(51401028)
文摘This paper reports crystal structures, magnetic properties and thermal stability of TbCu7-type Sm(8.5)Fe((85.8-x)Co(4.5)Zr(1.2)Nbx(x = 0-1.8) melt-spun compounds and their nitrides, investigated by means of X-ray diffraction, vibrating sample magnetometer, flux meter and transmission electron microscope. It is found that the lattice parameter ratio c/a of TbCu7-type crystal structure increases with Nb substitution, which indicates that the Nb can increase the stability of the metastable phase in the Sm-Fe ribbons. Nb substitution impedes the formation of magnetic soft phase a-Fe in which reversed domains initially form during the magnetization reversal process. Meanwhile, Nb substitution refines grains and leads to homogeneous micro structure with augmented grain boundaries. Thus the exchange coupling pining field is enhanced and irreversible domain wall propagation gets suppressed. As a result, the magnetic properties are improved and the irreversible flux loss of magnets is notably decreased. A maximum value 771.7 kA/m of the intrinsic coercivity H(cj) is achieved in the 1.2 at% substituted samples.The irreversible flux loss for 2 h exposure at 120 ℃ declines from 8.26% for Nb-free magnets to 6.32% for magnets with 1.2 at% Nb substitution.
基金Funded by the National Natural Science Foundation of China(No.31170558)
文摘To develop an efficient and bio-compatible way to improve the thermal and mechanical properties of addition type liquid silicone rubber(LSR), a series of modified LSR samples were prepared by introducing octavinyl-polyhedral oligosilsesquioxanes(VPOSS) and high purity silicon sol singly or in combination before vulcanization. Significant correlation was found between the loading rate of VPOSS and thermal properties. However, mechanical properties were negatively correlated with VPOSS content within the range experimented, which may be ascribed to material defect caused by uneven distribution and aggregation. Furthermore, test results approved that the introducing of silicon sol indeed affected the stabilities of the polymer by restraining the material defect caused by the aggregation of POSS molecules and improving cross link density. For example, adding 10%-20% of silicon sol into VPOSS(1.0%) modified LSR will increase tear resistance by 43.9%-85.7%, elongation at break by 31.7%-57.3%, residue at 800 ℃ in N2 atmosphere by 32.0%-37.9%, residue at 650 ℃ in air atmosphere by 70.9%-91.6%, respectively. This work proves that, to incorporate VPOSS into LSR by hydrosilylation, and to use silicon sol as dispersant and reinforce filler can become an efficient way to improve the mechanical property, thermal stability and bio-compatibility of LSR in the future.
基金Funded by the National Natural Science Foundation of China(No.60808024)
文摘The effect of Ga_2O_3 on the structure and properties of calcium aluminate glasses fabricated by vacuum melting process was investigated by Raman spectrum, differential scanning calorimeter(DSC), and infrared spectrum methods. The results show that calcium aluminate glass network only consists of [AlO_4] tetrahedral units. With the gradual addition of Ga_2O_3, the quantity of [GaO_4] tetrahedral units increases. Substitution of Ga_2O_3 for Al_2O_3 results in a decrease in Tg, Tx, and Tp, and an increase in the thermal stable index ΔT. Similarly, the absorption band around 3.0 μm obviously reduces and the transparency in 4.0-6.0 μm rapidly increases with increasing Ga_2O_3 content. However, the chemical stability of calcium aluminate glasses decreases if Ga_2O_3 is introduced due to the increasing of [GaO_4] units in the glass network.
文摘The present work establishes a systematic approach based on the application of in-situ Fourier transform infrared spectroscopy (FTIR) for the investigation of the crystal structure, thermal stability, redox behavior (temperature-programmed reduction/temperatureprogrammed re-oxidation) as well as the catalytic properties of Co3O4 thin films. The syntheses of Co3O4 were achieved by chemical vapor deposition in the temperature range of 400-500℃. The structure analysis of the as-prepared material revealed the presence of two prominent IR bands peaking at 544 cm-1 (υ1) and 650 cm-1 (υ2) respectively, which originate from the stretching vibrations of the Co-O bond, characteristic of the Co3O4 spinel. The lattice stability limit of Co3O4 was estimated to be above 650℃. The redox properties of the spinel structure were determined by integrating the area under the emission bands υ1 and υ2 as a function of the temperature. Moreover, Co3O4 has been successfully tested as a catalyst towards complete oxidation of dimethyl ether below 340 ℃. The exhaust gas analysis during the catalytic process by in situ absorption FTIR revealed that only CO2 and H2O were detected as the final products in the catalytic reaction. The redox behavior suggests that the oxidation of dimethyl ether over Co3O4 follows a Mars-van Krevelen type mechanism. The comprehensive application of in situ FTIR provides a novel diagnostic tool in characterization and performance test of catalysts.
基金supported by the National Natural Science Foundation of China(41472047)Science Research Starting Project of Chuzhou University(2014qd035)Student Creative Project of Chuzhou University
文摘A new Sr(Ⅱ) complex, [Sr(Hsip)(H2O)] (1, NaH2sip = 5-sulfoisophthalic acid monosodium), has been synthesized by solvothermal reaction of SrCO3 and NaH2sip at 120 ℃, and characterized by single-crystal X-ray diffraction studies, elemental analysis and FT-IR. Single- crystal X-ray diffraction reveals that compound 1 has a 3D architecture, and there is only one crystallographically independent Sr(Ⅱ) ion in 1. The coordination geometry of Sr(Ⅱ) is a distorted tetragonai anti-prism. The whole Hsip2- ligand performs aμ6-coordination model. In the solid state, complex 1 shows luminescence with the maximum emission intensity at 417 nm upon excitation at 320 nm. Thermal stability of complex 1 was also investigated.
基金Funded by the National Natural Science Foundation of China (No. 60372002)
文摘Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.
基金financially supported by the State Key Development Program of Basic Research of China (No. 2010CB934600)State Key Laboratory of Advanced Metals and Materials (No. 2011-ZD02)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges under Beijing Municipality (No. 009000543113507)
文摘Structure, magnetic properties, and thermal stability of ternary Sm1-xTmxCo5 compounds were studied via X-ray diffraction(XRD), thermal magnetic analysis(TMA), and magnetic measurements. XRD results show that all the compounds have a main phase of hexagonal CaCu5-type crystal structure with small amount of impurity phases; increasing Tm content is associated with contraction of the hexagonal unit cell in the direction of the c axis and expansion of the a and b parameters. TMA results indicate that the Curie temperature(TC) of Sm1-xTmxCo5 compounds gets higher with the increase in Tm content.Magnetic measurements show that both the magnetic anisotropy field(HA) and the magnetization at an applied field of 7 T(M7 T) decrease with the increase of Tm content. However, the thermal stability of both the HAand M7 Tof all the Tm doped compounds is remarkably improved compared with that of the pure SmCo5 compound, leading to the result that both the M7 Tand HAof Sm0.8Tm0.2Co5 .2are higher than those of SmCo5 compound at 473 K, which indicates the good potential of Tm doped compound in the practical applications at elevated temperature.
基金financially supported by the National Natural Science Foundation of China(51343008)
文摘The effects of mesogen-jacketed liquid crystalline polymer poly(dipropyl vinylterephthalate)(PDPVT) on the mechanical and thermal properties of diglycidyl ether of bisphenol-A(DGEBA) epoxy resin were investigated by impact test, tensile test and thermogravimetric analysis(TGA). The mechanism underlying the enhancement of mechanical properties of epoxy resin was studied using 1D wide-angle X-ray diffraction(WAXD) and scanning electron microscope(SEM). It was found that the mechanical properties of 1 wt%–5 wt% PDPVT/DGEBA composites were significantly improved compared to neat epoxy resin. Especially, the epoxy resin with 3 wt% PDPVT had the greatest increase in mechanical properties, with the impact strength, tensile strength and elongation while breaking increased by 87%, 59% and 174%, respectively. The increased mechanical strength was due to the fact that PDPVT maintained liquid crystalline phase in cured PDPVT/DGEBA composites, which would blunt the crack tip and prevent crack propagation. Moreover, PDPVT had slight effect on the thermal stability properties of epoxy resin.