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六水氯化钐与甘氨酸丙氨酸三元固态配合物的热化学 总被引:2,自引:0,他引:2
合成了 Sm3 +与甘氨酸丙氨酸混配体配合物 ,通过红外光谱分析、热重分析和化学分析 ,确定了配合物的组成为 :Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O,并用溶解量热法分别测定了 Sm Cl3 · 6H2 O( s) ,2 Gly( s) + 3Ala( s)和 Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O( s)在 2 mol/L HCl中的溶解焓 ;再根据盖斯定律设计了一个热化学循环 ,计算得到了六水氯化钐与甘氨酸丙氨酸反应的反应焓△ r Hθm( 2 98.1 5 K) =2 .1 60 k J/mol,并求出了 Sm( Gly) 2 ( Ala) 3 Cl3 · 2 H2 O( s)标准生成焓△f Hθm[Sm( Gly) 2 ( Ala) 3 Cl3 ·2 H2 O,s,2 98.1 5 K]=- 44 81 .5 k J/mol 相似文献
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用新型的具恒温环境的反应热量计 ,以 2 mol/L HCl为量热溶剂 ,分别测定了 Dy Cl3·6H2 O (s) +3Gly(s) (Gly代表甘氨酸 )和配合物 Dy(Gly) 3Cl3· 3H2 O(s)在 2 mol/L HCl溶液中的溶解焓变。根据盖斯定律设计了一个热化学循环 ,计算得到六水氯化镝与甘氨酸配位反应的反应焓Δr Hθm(2 98.2 K) =- 2 6.2 89k J/mol,并估算出配合物 Dy(Gly) 3Cl3· 3H2 O的标准生成焓 Δr Hθm(2 98.2 K) =- 3650 .5k J/mol。 相似文献
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室温下合成了6种未见报道的固态含能配合物M(BTA)(bpy)m.nH2O(M=Mn,m=1,n=1;M=Co,m=2,n=5;M=Ni,m=2,n=6;M=Cu,m=2,n=0;M=Zn,m=2,n=1;M=Pb,m=1,n=0;BTA=N,N’-二四唑胺离子,bpy=2,2’-联吡啶),对它们进行了组成、红外光谱、密度等表征。测定了298.15 K下各配合物的液相生成反应焓变△rHmθ,改变液相反应温度,在实验和计算基础上,得到了液相生成反应的热力学参数(活化焓△Hθ≠、活化熵△S≠θ和活化自由能△Gθ≠)、速率常数k和动力学参数(表现活化能E、频率因子ln[A/s]和反应级数n)。 相似文献
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采用PAN为显色剂,通过分光光度法测定反应体系中催化剂Pd(PPh3)2Cl2的浓度,以探讨氯苄单羰基化合成苯乙酸反应中Pd(PPh3)2Cl2水解失活的动力学方程.结果表明,Pd2+与PAN显色的较佳条件为在10 mL 1~20×10-6Pd2+含量的溶液中,加入0.5 mL0.04%的PAN,在pH=3.0、40℃的水浴中加热30 min;其摩尔吸光系数e=1.384×104 L·mol-1·cm-1;Pd(PPh3)2Cl2水解反应对三苯基膦氯化钯浓度呈0.5级;对三苯基膦浓度呈-0.8级;对苯乙酸浓度呈2级;对碱中和剂NaOH的浓度呈1.2级.Pd(PPh.)2C12水解反应的活化能E=75.59 kJ·mol-1,指前因子为1.68×1012. 相似文献
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使用具有恒定温度环境的反应热量计,以溶解热法及针对配位反应所设计的热化学循环,得到该反应的标准反应焓△rHθm(298.15K)=-27.924kJ·mol-1,并求得配合物Cu(p-tol)2Cl2的标准生成焓,其值推荐为△fHθm[Cu(p-tol)2Cl2,s]=-343.374kJ·mol-1。 相似文献
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制备了2-氨基嘧啶(AP)与镍的配合物Ni(AP)2Cl2,并对其组成进行了测定,采用具有恒温环境的溶解-反应量热计,分别测定了298.15 K时[NiCl2.6H2O(s) 2AP(s)]和Ni(AP)2Cl2(s)在100.00 mL 2 mol/L HCl溶液中的溶解焓。通过设计热化学循环得到2-氨基嘧啶(AP)和氯化镍反应的反应焓ΔrHmΘ=21.17±0.09 kJ/mol,进而计算出配合物Ni(AP)2Cl2在298.15 K时的标准摩尔生成焓为ΔfHΘm[Ni(AP)2Cl2,(s),298.15 K]=-458.82±3.41 kJ/mol. 相似文献
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提出了一个估算NTO负一价离子标准水合Gibbs自由能ΔhGθm(NTO-,g)的简易公式.用所建立的估算式和热力学关系式,算得ΔhGθm(NTO-,g)=-267.24kJ·mol-1,ΔhSθm(NTO-,g)=380.71J·(K·mol)-1.用热化学循环,算得体系[Mn (g) nNTO-(g) mH2O(g)](M=La,Ce,Pr,Eu,Sm,Gd,n=3,m=7;M=Y,Yb,n=3,m=6;M=Dy,Tb,n=3,m=5;M=Nd,n=3,m=8)水合过程的焓变. 相似文献
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在298.15 K下,用滴定式微量热法对α-、β-环糊精(α-/β-CD)与两个新型同系列表面活性剂3-烷氧基-2-羟丙基三甲基氯化铵(CnNC l,n=8,12)的包合作用进行了研究。结果表明,C8NC l与α-/β-CD均形成摩尔比为1∶1的稳定包合物,实验稳定常数分别为1.41×103dm3.mol-1和6.50×102dm3.mol-1;而C12NC l与α-/β-CD分别形成摩尔比为1∶2和1∶1的包合物,实验稳定常数分别为1.05×106dm6.mol-2和8.83×103dm3.mol-1。具有较长疏水链的C12NC l与两类环糊精包合过程的标准焓变(ΔHθ)和标准熵变(ΔSθ)较小。α-CD包合物的形成过程是焓驱动熵阻滞,而β-CD包合物的形成过程则是熵焓共同驱动。 相似文献
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Yong Sig Ko 《Powder Technology》2004,145(1):10-19
Zeolite L powder was prepared from the substrate mixture of Na2O-K2O-Al2O3-SiO2-H2O system at temperatures of 373-443 K. In order to investigate the factors which influence the synthesis outcome, a reference system which yields zeolite L in a reproducible manner was chosen and subjected to controlled changes in synthesis parameters. The crystalline zeolite L samples obtained were characterized by elemental chemical analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). It was established that phase purity, morphology, and the size of crystals of crystalline product were affected by molar ratios of the substrate, such as SiO2/Al2O3, (K2O+Na2O)/SiO2, Na2O/(K2O+Na2O), and H2O/(K2O+Na2O). Amorphous silica powder (Zeosil) was the preferred silica source, and the crystallization rate was promoted by introducing gel aging, seeding, and rapid heating rate. 相似文献
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Cu2O/TiO2, Bi2O3/TiO2 and ZnMn2O4/TiO2 heterojunctions were studied for potential applications in water decontamination technology and their capacity to induce an oxidation process under VIS light. UV–vis spectroscopy analysis showed that the junctions-based Cu2O, Bi2O3 and ZnMn2O4 are able to absorb a large part of visible light (respectively, up to 650, 460 and 1000 nm). This fact was confirmed in the case of Cu2O/TiO2 and Bi2O3/TiO2 by photocatalytic experiments performed under visible light. A part of the charge recombination that can take place when both semiconductors are excited was observed when a photocatalytic experiment was performed under UV–vis illumination. Orange II, 4-hydroxybenzoic and benzamide were used as pollutants in the experiment. Photoactivity of the junctions was found to be strongly dependent on the substrate. The different phenomena that were observed in each case are discussed. 相似文献
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Thixotropic gels of the precursor powders of the titled compounds have been prepared by the addition of oxalic acid to the mixed solutions of metal salts at room temperature (≈ 27 °C). The clear sols of yttrium-zirconyl oxalate (YZO) and yttrium-cerium-zirconyl oxalate (YCZO) gelled within a few hours and were oven-dried at 40 °C. The various stages of gelation behaviour of the sols are explained on the basis of DLVO theory. By repeptizing the dried gel powders with water, concentrated sols were prepared. The gelation time as a function of chloride ion concentration is discussed for both sols. The nature of the temperature dependence of the dried gel powders was studied by means of thermogravimetric analysis and differential thermal analysis. Powder X-ray diffraction was used to study the crystallization behaviour of the dried amorphous gel powders. It is found that these powders crystallize in tetragonal phase when calcined at 850 °C for 1 h. Estimation of surface area and infra-red characterization have also been carried out for the prepared powders. 相似文献
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Thadsanee Thongkanluang Treedej KittiauchawalPichet Limsuwan 《Ceramics International》2011,37(2):543-548
Green pigments with high near infrared reflectance based on a Cr2O3-TiO2-Al2O3-V2O5 composition have been synthesized. Cr2O3 was used as the host component and mixtures of TiO2, Al2O3 and V2O5 were used as the guest components. TiO2, Al2O3, and V2O5 were mixed into 39 different compositions. The spectral reflectance and the distribution of pigment powder were determined using a spectrophotometer and a scanning electron microscope, respectively. It was found that a pigment powder sample S9 with a Cr2O3-TiO2-Al2O3-V2O5 composition of 80, 4, 14 and 2 wt%, respectively, gives a maximum near infrared solar reflectance of 82.8% compared with 49.0% for pure Cr2O3. The dispersion of pigment powders in a ceramic glaze was also studied. The results show that the pigment powder sample S9 is suitable for use as a coating material for ceramic-based roofs. 相似文献
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Al2O3-SiO2-TiO2一ZrO2复合陶瓷膜的制备与表征 总被引:1,自引:0,他引:1
采用Sol—Gel法制备出掺杂SiO2,TiO2及ZrO2改性的γ-Al2O3膜,并通过SEM,EPMA,AFM等测试手段对膜结构和性能进行表征。探讨了制膜工艺条件对膜性能及结构的影响。制备的Al2O3复合膜膜厚为1—2μm,结构均匀无缺陷。 相似文献
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Yu. F. Shepelev A. E. Lapshin M. A. Petrova A. S. Novikova 《Glass Physics and Chemistry》2005,31(5):690-693
The crystal structure of the LiNaZnP2O7 compound is determined using X-ray powder diffraction (space group Cmcm, a = 12.431 Å, b = 7.589 Å, c = 6.283 Å). The structure has a mixed tetrahedral framework consisting of the diortho groups [P2O7] and the tetrahedra [ZnO4] and [LiO4], which are joined into chains. The [ZnO4] and [LiO4] tetrahedra are distributed in the chains in a random manner, because the zinc and lithium atoms statistically occupy one
crystallographic position. The sodium cations are arranged in channels of the tetrahedral framework. The atomic coordinates
and interatomic distances in the structure are reported.
Original Russian Text Copyright ? 2005 by Fizika i Khimiya Stekla, Shepelev, Lapshin, Petrova, Novikova. 相似文献
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Xueming Chen 《Electrochimica acta》2005,50(20):4155-4159
RuO2-based electrodes are generally known to be unstable for O2 evolution. In this paper, a stable type of RuO2-based electrode, Ti/RuO2-Sb2O5-SnO2, is demonstrated for O2 evolution. In the ternary oxide coating, RuO2 serves as the catalyst, SnO2 as the dispersing agent, and Sb2O5 as the dopant. The accelerated life test showed that the Ti/RuO2-Sb2O5-SnO2 electrode containing 12.2 molar percent of RuO2 nominally in the coating had a service life of 307 h in 3 M H2SO4 solution under a current density of 0.5 A cm−2 at 25 °C, which is more than 15 times longer than other types of RuO2-based electrodes. Instrumental analysis indicated that RuO2-Sb2O5-SnO2 was a solid solution with a compact structure, which contributed to the stable nature of the electrode. 相似文献
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The crystallization of zeolites in the SiO2-Al2O3-Na2O-K2O-(TEA)2O-H2O system, where (TEA)2O is tetraethylammonium oxide, has been investigated over a wide range of variations in the SiO2: Al2O3 ratio (from 5 to 19). It has been found that, in the composition region under investigation, zeolites crystallize with structures
of paulingite, beta, phillipsite, merlinoite, erionite, mordenite, and garronite. The formation of the aforementioned phases
is determined by the composition of the initial gels and the synthesis temperature. The cocrystallization of paulingite, phillipsite,
and merlinoite is explained by the structural features of these zeolites. 相似文献