γ—Mo2N合成过程中的热变化及中间产物的研究

采用ＤＴＡ技术，通过改变升温速率研究了γ－Ｍｏ２Ｎ合成过程中的热变化，并经ＸＲＤ，ＢＥＴ及ＩＲ测试，对ＤＴＡ曲线中的谱峰进行归属，考察了中间产物，ＤＴＡ结果表明，在ＭｏＯ３和ＮＨ３程序升温反应过程中有放热峰及吸热峰出现，且随升温速率的长高，放热峰面积与吸热峰面积之比逐渐减小，结合ＸＲＤ及ＩＲ结果可知，ＤＴＡ曲线听放热峰可归属为由ＭｏＯ３变化为ＭｏＯ２的还原峰，吸热峰则归属为由ＭｏＯ２变化为Ｍｏ２Ｎ     

煤系高岭土的DTA特征

利用程序升温热分析法得到煤系高岭土在不同气氛下的ＴＧ／ＤＴＡ谱图。通过比较煤系高岭土与普通高岭土的ＴＧ／ＤＴＡ谱图，可以发现：在惰性气氛下煤系高岭土的ＤＴＡ谱图与普通高岭土的谱图基本一致；而在空气气氛下，由于煤的燃烧反应致使煤系高岭土的吸热谷被部分或全部遮盖，另外在３００℃左右有弱的放热峰出现。比较煤系高岭土与普通高岭土的吸热谷特征可以得出煤系高岭土的结构完整性与结晶度较差。     

水合溴化镧的脱水动力学及与二甲基亚砜配合物的合成和热分析研究

合成了水合演化镧和演化镧与二甲基亚砜（ＤＭＳＯ）的配合物，经化学分析和红外光谱确定其组成分别为ＬａＢｒ３．７Ｈ２Ｏ和ＬａＢｒ３·７ＤＭＳＯ。应用ＴＧ－ＤＴＡ－ＤＴＧ联用技术研究了水合盐的脱水过程；由ＤＴＡ法测得脱水焓值。依据ＴＧ、ＤＴＡ数据进行了动力学分析。求出了第一、第二阶段脱水反应的活化能并推断出脱水反应机理。用相同的技术研究了ＬａＢｒ３·７ＤＭＳＯ的热分解过程。     

Li^＋忘记尖晶石构造LiAlMnO4的合成及离子交换性能

用共沉淀／热结晶法制备了尖晶石型金属复合物ＬｉＡｌＭＮＯ４用Ｘ－射线衍射、ＤＴＡ－ＴＧ分析、ＦＴ－ＩＲ光谱／ＰＨ滴定和Ｋｄ测定研究了该化合物的Ｌｉ＾＋抽出，嵌入及离子交换性质。研究表明，Ｌｉ＾＋的抽出／嵌入过程主要是离子交换，为局部规整反应；该化合物酸处理产物对Ｌｉ＾＋的交换容量约４．５ｍｏｌ／ｇ，对Ｌｉ＾＋显著了忘记性离子筛效庆。     

Li~＋记忆尖晶石构造LiAlMnO_4的合成及离子交换性能

用共沉淀／热结晶法制备了尖晶石型金属复合氧化物ＬｉＡｌＭｎＯ４，用Ｘ－射线衍射、ＤＴＡ—ＴＧ分析、ＦＴ—ＩＲ光谱、ｐＨ滴定和Ｋｄ测定研究了该化合物的Ｌｉ＋抽出、嵌入及离子交换性质。研究表明，Ｌｌ＋的抽出／嵌入过程主要是离子交换，为局部规整反应；该化合物酸处理产物对Ｌｉ＋的交换容量约４．５ｍｍｏｌ／ｇ，对Ｌｉ＋显示了记忆性离子筛效应。     

Cu，Pd－ZSM－5上NO分解和CO氧化的催化作用

双交换Ｃｕ，ｐｄ－ＺＳＭ－５催化剂（Ｃｕ交换度为１０５％，Ｐｄ交换度分别为３．４％和３３％）对ＣＯ氧化反应有活性增强作用，对ＮＯ分解反应不存在增强效应．双交换催化剂在于交换程序不同，而表面物种不同，活性组分的分布状态不同，因而有不同的活性．先交换Ｃｕ，４００℃焙烧后再交换ｐｄ的Ｃｕ－Ｐｄ－ＺＳＭ－５催化剂，对上述两类反应的活性存双组分催化剂中均为最高．Ｈ_２－ＴＰＲ谱表明，共交换的Ｃｕ－Ｐｄ－ＺＳＭ－５中尚有部分ＣｕＣｌ＋占据了部分交换位置，而使ＣＯ氧化活性稍有下降．Ｎ_２－ＤＴＡ和Ｈ_２－ＴＰＲ谱结果表明，Ｐｄ交换到Ｃｕ－ＺＳＭ－５中后，抑制了吸附水和水合铜化合物的形成，由此提高了在２００—３００℃时氧的吸附量．后者的大小和ＣＯ氧化活性有顺变关系．Ｎ_２－ＤＴＡ谱中３４０—４４５℃的放热峰可能分别表征了和ＮＯ分解活性有关的铜氧桥或把氧桥的形成，该放热峰的峰温愈低，峰面积愈大，则ＮＯ分解活性愈高．     

水合溴化镧的脱水动力学及与二甲基亚砜配合物的合成和热分析…

合成了水合溴化镧和溴化镧与二甲基亚砜的配合物，经化学分析和红外光谱确定基组成分别为ＬａＢｒ．３７Ｈ２Ｏ和ＬａＢｒ３．７ＤＭＳＯ．应用ＴＧ－ＤＴＡ－ＤＴＧ联用技术研究了水合盐的脱水过程；由ＤＴＡ法测得脱水焓值。依据ＴＧ、ＤＴＡ数据进行了动力学分析。求出了第一、第二阶段脱水反应的活化能并推断出脱水反应机理。用相同的技术研究了ＬａＢｒ３．７ＤＭＳＯ的热分解过程。     

乙二胺四乙酸对锗（Ⅳ）—没食子酸体系及钒（Ⅳ）的示波极谱电流的影响

用分光光度法及电化学法详细研究了在稀硫酸介质，分别加ＥＤＴＡ到锗－没食子酸，Ｇｅ－ＧＡ－Ｖ体系以及Ｖ溶液中，所产生的影响。结果表明，ＥＤＴＡ使Ｇｅ－ＧＡ体系的两步２电子反应过程变得清Ｇｅ－ＧＡ－Ｖ体系因Ｖ２Ｈ３Ｙ＾－Ｇ形成，增强了Ｖ的化学氧化力。     

单一阴离子交换柱同时分离有机酸和无机阴阳离子

研究了用乙二胺四乙酸（ＥＤＴＡ）作淋洗液时，性质迥异的有机酸、无机阴离子和碱土金属离子（Ｃａ＾２＋、Ｍｇ＾２＋）在同一阴离子交换柱上的同时分离以及保留机理，结果表明，在离子交换机理之外，非离子交换机理对有机酸及钙镁的ＥＤＴＡ络阴郭的保留行为起一定的辅助作用，９种有机酸和无机阴阳离子在１０ｍｉｎ内得到了较好的分离。各离子的电导检测灵敏度在１０＾－９至１０＾－１１ｍｏｌ，能满足环境和食吕分析的要求。     

双缓血氨二乙三胺五乙酸酰胺钆,镱螯合物的合成及其弛豫性能

缓血氨（Ｔｒｉｓ，三羟甲基氨基甲烷）修饰多氨多羧酸（二乙三胺五乙酸，ＤＴＰＡ和乙二胺四乙酸，ＥＤＴＡ）得到两种新的双酰胺型氨羧衍生物配体ＤＴＰＡВＴｒｉｓ和ＥＤＴＡＢＴｒｉｓ，并合成了它们的Ｇｄ３＋，Ｙｂ３＋，Ｍｎ２＋，Ｆｅ３＋等顺磁性金属螯合物，研究了Ｇｄ３＋，Ｍｎ２＋和Ｆｅ３＋螯合物作为磁共振成像造影剂的主要性能。结果表明，ＧｄＤＴＰＡＢＴｒｉｓ，ＭｎＥＤＴＡＢＴｒｉｓ和ＦｅＥＤＴＡＢＴｒｉｓ在体外水溶液中对水质子的纵向弛豫率Ｒ１分别为５４，３．１和１．９Ｌ·ｍｍｏｌ－１·ｓ－１，均高于其相应母体螯合物在相同条件下的弛豫率。此外，这些螯合物还具有医用磁共振成像造影剂所要求的高水溶性和化学稳定性。     

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.