盐酸在硫酸镍水溶液中的活度系数

以标准氢电极和银-氯化银电极组成无液接电池,研究HCl-NiSO4-H2O体系.在恒定溶液总离子强度I=0.4、0.6、0.8、1.0、1.5 、2.0 mol•kg－1, NiSO4在溶液中的离子强度分数yB=0.00、0.10、0.20、0.30、0.50、0 .70的条件下,在278.15～323.15 K温度范围内测定电池: Pt, H2(101.325 kPa)│HCl(mA), NiSO4(mB), H2O│AgCl-Ag 的电动势.根据测得的电动势数据,考虑到体系存在硫酸的二级解离,应用数学迭代方法确定平衡体系氢离子的浓度,进而计算了混合溶液中HCl的活度系数γA.结果表明,在溶液中总离子强度保持恒定时, HCl 的活度系数服从Harned规则.     

葡萄糖和水混合溶液中多组份电解质溶液热力学I: HCl-NaCl-D-glucose-H2O体系(5-45℃)

本文在恒定葡萄糖质量百分数x=10%的条件下,应用电动势法测定无液体接界电池(A)和电池(B)的电动势: Pt,H2(1.013X10^5 Pa)|HCl(m),D-Glucose(x),H2O(1-x)|AgCl-Ag Pt,H2(1.013X10^5 Pa)|HCl(ｍA),NaCl(ｍA),D-Glucose(x),H2O(1-x)|AgCl-Ag (B) 根据电池(A)电动势确定混合液中的Ag-AgCl电极的标准电极电势,讨论了HCl的迁移性质;利用电池(B)的电动势确定了HCl在该体系中的活度系数γA,结果表明,在恒定总离子强度下,HCl的活度系数服从Harned 规则。在溶液组成恒定时,lgγA是温度倒数1/Τ的线性函数,进一步讨论了混合物中HCl的相对偏摩尔焓,计算了HCl的介质效应。     

葡萄糖和水混合溶液中多组份电解质溶液热力学I: HCl-NaCl-D-glucose-H2O体系(5-45℃)

本文在恒定葡萄糖质量百分数x=10%的条件下,应用电动势法测定无液体接界电池(A)和电池(B)的电动势: Pt,H2(1.013X10^5 Pa)|HCl(m),D-Glucose(x),H2O(1-x)|AgCl-Ag Pt,H2(1.013X10^5 Pa)|HCl(ｍA),NaCl(ｍA),D-Glucose(x),H2O(1-x)|AgCl-Ag (B) 根据电池(A)电动势确定混合液中的Ag-AgCl电极的标准电极电势,讨论了HCl的迁移性质;利用电池(B)的电动势确定了HCl在该体系中的活度系数γA,结果表明,在恒定总离子强度下,HCl的活度系数服从Harned 规则。在溶液组成恒定时,lgγA是温度倒数1/Τ的线性函数,进一步讨论了混合物中HCl的相对偏摩尔焓,计算了HCl的介质效应。     

硫酸铟水溶液热力学

在HCl-In2(SO4)3-H2O体系中,溶液表观总离子强度恒定为I=0.2、0.4、0.6、0.8、1.0、1.5 mol•kg－1,硫酸铟在溶液中的表观离子强度分数恒定为yB=0、0.10、0.20、0.30、0.50和0 .70条件下,应用电动势方法测定无液体接界电池(A)在278.15～318.15 K温度范围内的电动势Pt, H2(101.325 kPa)│HCl(mA),In2(SO4)3(mB),H2O│AgCl-Ag (A) 根据测得电池(A)的电动势数据,考虑到该体系存在硫酸的二级解离,应用数学迭代方法确定平衡体系氢离子的浓度,进而确定了混合溶液中HCl 的活度系数γA .     

盐酸在硫酸镁水溶液中的Harned规则

在盐酸-硫酸镁-水三元系混合介质中, 以标准H2电极和Ag-AgCl电极组成无液接电池, 应用经典的电动势(EMF)方法测定下列电池的电动势： Pt, H2 (101.325 kPa )│HCl (m＝0.01000 mol·kg-1)│AgCl-Ag (A) Pt, H2 (101.325 kPa)│HCl (mA), MgSO4 (mB), H2O│AgCl-Ag (B) 根据电池(A)得到Ag-AgCl电极在278.15、288.15、298.15、308.15和318.15 K等5个温度时纯水中的标准电极电势. 对电池(B)恒定体系总离子强度I为 0.2、0.4、0.6、0.8、1.0、1.5 mol·kg-1, 硫酸镁的离子强度分数yB恒定为 0.00、0.10、0.20、0.30、0.50和0.70, 测定电池(B)在278.15、288.15、298.15、308.15和318.15 K等5个温度时的电动势. 由于体系中存在硫酸的二级解离, 采用数学迭代方法确定平衡体系中氢离子的浓度, 根据测得电池(B)的电动势数据计算了混合溶液中盐酸的活度系数γA. 结果表明: 在溶液中总离子强度保持恒定时, 盐酸的活度系数服从Harned规则, 在组成恒定时混合物中HCl的活度系数lgγA对热力学温度T作图是一条直线. 进一步讨论了混合溶液中盐酸的相对偏摩尔焓．     

混合溶剂中多组分电解质溶液热力学性质的研究Ⅱ.HCl+NaCl+2-propanol+H_2O体系15～45℃

本文在恒定异丙醇摩尔分数x=0.05的条件下,应用电动势法测定无液体接界电池(A)和电池(B)的电动势:Pt,H_2(latm)|HCl(m),2-propanol(x),H_2O(1-x)|Agcl-Ag(A)和Pt,H_2(latm)|HCl(m_A),NaCl(m_B),2-propanol(x),H_2O(1-x)|AgCl-Ag(B)根据电池(A)电动势确定混合溶剂中的Ag-AgCl电极的标准电极电势,讨论了HCl的迁移性质;利用电池(B)电动势确定HCl在该体系中的活度系数γA,在恒定总离子强度下,HCl的活度系数遵守Harned规则。在溶液组成恒定时,logγA是温度倒数1/T的线性函数,讨论了混合物中HCl的相对偏摩尔焓,计算了HCl的一级、二级和总介质效应。     

混合溶剂中多组分电解质溶液热力学性质的研究I: 5-45℃下氯化氢-氯化钠-1,2-丙二醇-水体系

在恒定1,2-丙二醇摩尔分数X为0.05的混合溶剂中,在5-45℃温度范围内测定无液接电池Pt,H2(1 atm)HCl(ma),1,2-C3H5(OH)2(X),H2O(1-X)|AgCl-Ag(A)和Pt,H2(1 atm)|HCl(ma),NaCl(mb),1,2-C3H5(OH)2(X),H2O(1-X)|AgCl-Ag (B)的电动势.利用电池A的电动势确定混合溶剂中Ag-AgCl电极的标准电极电势,利用电池B的电动势确定了HCl在混合溶剂的多组分电解质溶液中的活度系数γA.指出了在恒定总离子强度下HCl仍然服从Harned规则,在溶液组成恒定时,logγA是温度T的线性函数.HCl的相对偏摩尔焓遵守类似的Harned规则,计算了HCl的一级、二级和总介质效应.     

混合溶剂中多组分电解质溶液热力学性质的研究Ⅱ. HCl+NaCl+2-propanol+H2O体系15～45 ℃

本文在恒定异丙醇摩尔分数x=0.05的条件下, 应用电动势法测定无液体接界电池(A)和电池(B)的电动势:Pt, H_2(latm)|HCl(m), 2-propanol(x), H_2O(1-x)|Agcl-Ag (A)和Pt, H_2(latm)|HCl(m_A), NaCl(m_B), 2-propanol(x), H_2O(1-x)|AgCl-Ag (B)根据电池(A)电动势确定混合溶剂中的Ag-AgCl电极的标准电极电势, 讨论了HCl的迁移性质; 利用电池(B)电动势确定HCl在该体系中的活度系数γ_A, 在恒定总离子强度下, HCl的活度系数遵守Harned规则。在溶液组成恒定时, logγ_A是温度倒数1/T的线性函数, 讨论了混合物中HCl的相对偏摩尔焓, 计算了HCl的一级、二级和总介质效应。     

葡萄糖和水混合溶液中多组份电解质溶液热力学——Ⅰ.HCl-NaCl-D-Glucose-H_2O 体系(5—45℃)

本文在恒定葡萄糖质量百分数 x=10%的条件下,应用电动势法测定无液体接界电池(A)和电池(B)的电动势:Pt,H_2(1.013×10~5 Pa)丨HCl(m),D-Glucose(x),H_2O(1-x)「AgCl-Ag (A)Pt,H_2(1.013×10~5Pa)丨HCl(m_A),NaCl(m_B),D-Glucose(x),H_2O(1-x)「AgCl-Ag (B)根据电池(A)电动势确定混合溶液中的 Ag-AgCl 电极的标准电极电势,讨论了 HCl 的迁移性质;利用电池(B)的电动势确定了 HCl 在该体系中的活度系数γ_A,结果表明,在恒定总离子强度下,HCl 的活度系数服从 Harned 规则.在溶液组成恒定时,lgγ_A 是温度倒数1/T 的线性函数,进一步讨论了混合物中 HCl 的相对偏摩尔焓,计算了 HCl 的介质效应.     

葡萄糖和水混合溶液多组分电解质热力学 Ⅱ.HCl-NaCl-d-Glucose-H_2O体系(5—45℃)

本文续前报在恒定溶液总离子强度I=1.00mol·kg~(-1),改变葡萄糖在混合溶液中的质量百分数x=5%、15%和20%的条件下,应用电动势法测定了无液接界电池(A)和电池(B)的电动势: Pt,H_2(1.013×10~5Pa)|HCl(m),d-Glucose(x),H_2O(1-x)|AgCl-Ag (A) Pt,H_2(1.013×10~5Pa)|HCl(m_A),NaCl(m_B),d-Glucose(x),H_2O(1-x)|AgCl-Ag(B) 其中x代表葡萄糖在水中的质量百分数,m_A和m_B分别是HCl和NaCl在混合溶液中的质量摩浓度。利用电池(A)的电动势数据得到了AgCl-Ag电极在d-Glucose-H_2O混合溶液中的标准电极电势Φ_m~0,讨论了HCl的迁移性质,利用电池(B)的电动势数据,确定了HCl在HCl-NaCl-d-Glucse-H_2O体系中的活度系数γ_A,实验结果表明:在恒定总离子强度下,HCl的活度系数服从Harned规则。HCl的迁移自由能与葡萄糖的质量百分数x成线性关系。计算了HCl     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.