在与水混溶有机溶剂体系中流动注射光度测定钯

本文研究了在乙醇－水载流体系中钯的流动注射光度法。二硫代乙二酰胺为显色剂，在波长４２０ｎｍ处检测，测定钯的在线性范围为２．０～１２．０μｇ／ｍＬ，进样频率达２４０次／ｈ。方法有较好的选择性，适合于各催化剂、合金和王水不溶渣中微量和较高含量钯的分析。     

双波长分光光度法同时测定贵金属钯和锇

本文提出了在对羟基苯基荧光酮和溴化十六烷基三甲烷基甲胺存在下，双波长分光光度法同时测定微量和锇的新方法，在ｐＨ＝７．６～８．０的磷酸盐介质中，钯和锇的对羟基苯基荧光酮－ＣＴＭＡＢ配合物吸收光谱相互重叠，选择测定钯配合物的波长对为５８０．５ｎｍ与５３０．５ｎｍ，测定锇配合物的波长对为５５３．５ｎｍ与６０４．５ｎｍ，钯含量在０～７．０μｇ／１０ｍＬ范围内，锇含量在０～９．０μｇ／ｍＬ范围内，与ΔＡ值呈     

氯代十六烷基吡啶存在下钯与1,4—双肼酞嗪新显色反应的研究

本文研究了１，４－双肼酞嗪（ＤＨＰＨ）与钯的配合显色反应，在阳离子型表面活性剂氯代十六烷吡啶存在下，在０．１～０．２ｍｏｌ／ＬＨＣｌ溶液中，试剂与钯形成１：１的稳定的亲黄绿色配合物，最大吸收峰在４００ｎｍ处，表观摩尔吸光系数为２．６×１０＾４。钯量在０～５０μｇ／２５ｍＬ范围内股从比尔定律，方法简便快速，选择性好，已用于催化剂中钯的测定，结果满意。     

氯代十六烷基吡啶存在下钯与1，4－双肼酞嗪新显色反应的研究

本文研究了１，４－双肼酞嗪（ＤＨＰＨ）与钯的配合显色反应，在阳离子型表面活性剂氯代十六烷基吡啶存在下，在０．１～０．２ｍｏｌ／ＬＨＣｌ溶液中，试剂与钯形成１：１的稳定的黄绿色配合物，最大吸收峰在４００ｎｍ处，表观摩尔吸光系数为２．６×１０￣４，钯量在０～５０μｇ／２５ｍＬ范围内股从比尔定律，方法简便快速，选择性好，已用于催化剂中钯的测定，结果满意。     

石蜡相分光光度法测定微量钯

以石蜡为固体萃取剂，系统地探讨了钯－丁二酮肟（ＤＭＧ） 显色体系在石蜡相最佳显色条件及光度特性。钯的浓度在０～８０ ｍ ｇ／５０ Ｌ范围内符合比尔定律，相关系数ｒ＝ ０．９９９７。方法检出限为１．７５×１０－ ５ｇ／Ｌ。该法选择性好，大多数常见离子不干扰钯的测定，灵敏度比液相光度法高。应用于分子筛中微量钯的测定，结果良好。     

泡沫塑料对贵金属—碘化亚锡—络合物的吸附分离行为研究

本文通过泡沫塑料对贵金属－碘化亚锡体系富集分离的条件，怀能和朵理的研究，建立了一种泡沫塑料同时富集分离微量铂，钯，铑，铱，金的新体系。实验结果表明，在１．０ｍｏｌ／ＬＨＣｌ，０．６ｍｏｌ／ＬＫＩ和０．０１ｍｏｌ／ＬＳｎＣｌ２的溶液中，振荡吸附３０ｍｉｎ。各元素分配系数均在１０＾５以上，吸附容量（ｍｍｏｌ／ｇ）分别为：铂０．２５，钯０．２４，铑０．１２，铱０．１０，金０．５２，回收率分别为：铂９９．     

新催化动力学光度法测定痕量钯

在磷酸－邻苯二甲酸氢钾缓冲溶液（ｐＨ２．０）中,利用钯（Ⅱ）对次磷酸钠还原二甲苯蓝ＦＦ褪色的催化作用,建立了用斜率法测定痕量钯的新动力学分光光度法。在加入金（Ⅲ）的条件下,钯（Ⅱ）的检测下限为２．７×１０－１１ｇ／ｍＬ,线性范围为０．０４～６．０ｎｇ／ｍＬ。该法已应用于测定二次阳极泥中钯的含量。     

N_（1923）萃淋树脂对钯吸萃性能及机理的研究

Ｎ＿（１９２３）萃淋树脂是胺类萃淋树脂。本文报道了该树脂在酸性体系中对钯的静态分配比。讨论了温度、树脂用量，振摇时间对吸附钯的影响。确定了吸萃物的组成比，并用红外光谱探讨了树脂吸附钯的机理。在此基础上，进行树脂的柱色层试验，结果表明此树脂为萃取色层的新固定相，树脂上吸附的钯可用０．０５０ｍｏｌ／Ｌ硫脲－０．５０ｍｏｌ／ＬＨＣｌ溶液解脱，树脂可再生和重复使用。     

铁基体离子注入钯的腐蚀行为

研究了铁基体离子注入钯后的腐蚀行为。钯离子注入剂量为１×１０＾６～１×１０＾１８离子．ｃｍ＾－２注入能量４０ｄｅＶ．在ｐＨ＝５．０的０．５ｍｏｌ／Ｌ ＮａＡｃ／ＨＡｃ缓冲溶液中，用动电位扫描法测量了注钯后的铁的阳极溶解过程，用开腐蚀电位与浸泡时间的关系研究了修饰材料的耐蚀性。结果表明，钯离子的注入降低了铁的临界钝化电流，在ｐＨ＝５．０的醋酸盐缓冲溶液中保持较好的钝性。但当注入电极表面的氧化膜被还原     

平台石墨炉原子吸收法测定高温镍基合金中铋

本文用１ｍｇ／ｍＬ镍和０．２ｍｇ／ｍＬ钯作混合基体改进剂，提高了测定铋的灰化温度和抗干扰能力，且灵敏度几乎不变。可不经分离样品基体，直接用平台石墨炉原子吸收法测定高温镍基合金中铋。方法特征量为１８ｐｇ，检出限为０．０８１μｇ／ｇ。对含０．３－０．７μｇ／ｇ铋的镍基样品测定，相对标准偏差为３．０％－５．９％，回收率在８５％－１１９％之间。     

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.