两性高分子的溶液性质

两性高分子是分子链上同时含有正负电荷基团的一类高聚物、具有独特的溶液性质。本文就两性高分子等电点的构象状态、影响等电点的因素、两性高分子的溶解性以及高分子结构和组成、ｐＨ、溶液离子强度、混合溶剂、温度对流体力学行为的影响进行了综述。     

纳米二氧化锆制备过程的DSC、TGA和XRD研究

用ＤＳＣ、ＴＧＡ和ＸＲＤ技术研究了在沉淀法制备纳米ＺｒＯ２的过程中，残留ＮＨ４Ｃｌ、ｐＨ值、滴加方式、以及结构稳定剂Ｙ２Ｏ３的添加量对结晶过程的影响。结果表明，残留ＮＨ４Ｃｌ使结晶化温度降低，使放热过程变为吸热过程。而ｐＨ值、滴加方式和结构稳定剂的添加对结晶过程无明显影响。     

Gd（ClO_4）_3·3H_2O－18C6－CH_3CN三元体系25℃相平衡研究及配合物的合成与表征

采用半微量相平衡方法研究了Ｇｄ（ＣｌＯ_４）_３·３Ｈ_２Ｏ－１８Ｃ６－ＣＨ_３ＣＮ三元体系在２５℃时的溶解度，测定了饱和溶液的折光率。结果表明，该体系在２５℃时形成两种化学计量的配合物，其组成分别为：Ｇｄ（ＣｌＯ_４）_３·１８Ｃ６·３Ｈ_２Ｏ·２ＣＨ_３ＣＮ和Ｇｄ（ＣｌＯ_４）_３·２（１８Ｃ６）·３Ｈ_２Ｏ·２ＣＨ_３ＣＮ，制备了固态配合物，用化学分析及元素分析、ＩＲ、ＤＴＧ、ＴＧ及ＤＳＣ等研究了配合物的组成与性质。     

固定化谷氨酸脱羧酶柱式反应器测定L—谷氨酸

用羧甲基化的Ｎ,Ｎ’－甲叉双丙烯酰胺交联的烯丙基葡萄糖（简称ＣＭ－ＣＡＤＢ）凝胶树脂为新型载体,研究了谷氨酸脱羧酶（ＧＤＣ）在ＣＭ－ＣＡＤＢ上的固定化与环境的依赖头等确定了酶固定化最佳条件,研究了固定化ＧＤＣ的性状与底物浓度,ｐＨ温度的依存性,动态响应特性,热稳定性的寿命,求算了米氏常数。将固定化ＧＤＣ酶柱与进样系统具ＣＯ２气敏电极的离子活度分析器－计算机数据采集系统匹配,构成酶反应谷氨酸检测装置     

固定化谷氨酸脱羧酶性能的研究

本文首镒用羧甲基化的以Ｎ,Ｎ’－甲叉双丙烯酰胺交联的烯丙基葡聚糖凝胶生化树脂为新型载体,将谷氨酸脱羧酶固定在ＣＭ－ＣＡＤＢ树脂上。研究了固定化ＧＤＣ的活性与低物浓度,ｐＨ,温度的依存性;动态响应特性;热稳定性和寿命;求算了米氏常数和反应活化能;将固定化ＧＤＣ酶柱与进样系统－离子活度分析器－计算机数据采集系统匹配,构成酶传感器谷氨酸检测装置,测定了固定化ＧＤＣ酶柱的能斯特线性响应曲线,线性方程为ｙ／     

Y（ClO4）3·3H2O—B15C5—CH3CN三元体系在20℃时的半微量相平…

采用半微量相平衡方法研究了Ｙ（ＣｌＯ４）３·３Ｈ２Ｏ－Ｂ１５Ｃ５－ＣＨ３ＣＮ三元体系在２０℃时的溶解度，测定了各饱和溶液的折光率。该体系于２０℃生成两种化学计量的配合物，其组成分别为Ｙ（ＣｌＯ４）３·Ｂ１５Ｃ５·３Ｈ２Ｏ·２．５ＣＨ３ＣＮ和Ｙ（ＣｌＯ４）３·２Ｂ１５Ｃ５·３Ｈ２Ｏ·ＣＨ３ＣＮ。用ＩＲ光谱、电导、ＤＴＧ、ＴＧ和ＤＳＣ研究了配合物的组成和性质。     

Y（ClO_4）_3·3H_2O－B15C5－CH_3CN三元体系在20℃时的半

采用半微量相平衡方法研究了Ｙ（ＣｌＯ_４）_３·３Ｈ_２Ｏ－Ｂｌ５Ｃ５－ＣＨ_３ＣＮ三元体系在２０℃时的溶解度，测定了各饱和溶液的折光率．该体系于２０℃生成两种化学计量的配合物，其组成分别为Ｙ（ＣｌＯ_４）_３·Ｂ１５Ｃ５·３Ｈ_２Ｏ·２．５ＣＨ_３ＣＮ和Ｙ（ＣｌＯ_４）_３·２Ｂ１５Ｃ５·３Ｈ_２Ｏ·ＣＨ_３ＣＮ。用ＩＲ光谱、电导、ＤＴＧ、ＴＧ和ＤＳＣ研究了配合物的组成和性质。     

三水合氯化镨与18C6在乙醇中的配位行为及配合物的合…

采用半微量相平衡方法研究了ＰｒＣｌ３．３Ｈ２Ｏ－１８Ｃ－Ｃ２Ｈ５ＯＨ三元体系在２５℃的溶解度，测定了各饱和溶液的折光率，在该体系中有三种化学计量的配合物形成，其化学组成为：２ＰｒＣｌ３．１８Ｃ６．６Ｈ２Ｏ．Ｃ２Ｈ６ＯＨ，４ＰｒＣｌ３．３（１８Ｃ６）．１２Ｈ２Ｏ和ＰｒＣｌ３．１８Ｃ６．３Ｈ２Ｏ依据相平衡结果，合成了三咱固态配合物，利用化学分析、ＩＲ、ＴＧ、ＤＴＧ、ＤＳ电导研究了配合物的组成和性质。     

聚丙烯酰胺/柠檬酸铝胶态分散凝胶性质的研究

用低浓度不同分子量的部分水解聚丙烯酰胺（ Ｈ Ｐ Ａ Ｍ） 和柠檬酸铝制备了胶态分散凝胶（ Ｃ Ｄ Ｇ） ,并用奥氏粘度计、超细粒度分析仪、岩芯流动实验对 Ｃ Ｄ Ｇ 的性质进行了研究．结果表明, Ｃ Ｄ Ｇ 的粘度比 Ｈ Ｐ Ａ Ｍ 粘度低,粒径在４５０ ～５２０ｎ ｍ 之间．岩芯流动实验结果表明, Ｃ Ｄ Ｇ 能够使岩芯的流动阻力大幅度增加,且在岩芯中达到同样的流动阻力所需通过 Ｃ Ｄ Ｇ 的体积与形成 Ｃ Ｄ Ｇ 的 Ｈ Ｐ Ａ Ｍ 的分子量、浓度及岩芯渗透率有关．     

硫代苹果酸作为络合滴定掩蔽剂的研究

本系统地研究了硫代苹果在络合滴定中的掩蔽性能，发现它在ｐＨ１．５～１０可作为Ｓｎ＾４＋、Ｓｂ＾３＋、Ｔｂ＾３＋、Ｂｉ＾３＋、Ｃｕ＾２＋、Ｈｇ＾２＋和Ａｇ＾＋等的掩蔽剂（在ｐＨ２～３．５还可掩蔽Ｆｅ＾３＋）。掩蔽上述离子后，可在ｐＨ２．５～３用Ｔｈ＾４＋回滴ＥＤＴＡ，在ｐＨ５～６用ＥＤＴＡ滴定Ｚｎ＾２＋或Ｙｂ＾３＋等，或在ｐＨ１０用ＥＤＴＡ滴定Ｍｇ＾２＋、Ｃａ＾２＋、Ｍｇ＾２＋＋Ｃａ＾２＋和Ｍｎ＾     

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.