铁基高温变换催化剂制备的穆斯堡尔谱研究Ⅰ.铁氧化物前驱态的相变过程

用穆斯堡尔谱及ＸＲＤ技术对不同铁氧化物前驱态的相变过程进行了，ＦｅＣＯ３沉淀在空气中老化时被氧化分解生成ＦｅＯ（ＯＨ），经干燥、煅烧后合部转化为ａ－Ｆｅ２Ｏ３。（Ｆｅ（ＯＨ）２沉淀物在空气中老化时则转化为Ｆｅ３Ｏ４．２Ｈ２Ｏ和ＦｅＯＯＨ，两者的相对含量受Ｆｅ＾２＋的迁移速率和Ｆｅ（ＯＨ）２的氧化速度的影响。     

α-Fe_2O_3在LiOH水溶液中的锂化行为

用循环伏安和红外光谱法对α－Ｆｅ_２Ｏ_３在室温ＬｉＯＨ溶液中的锂化行为进行研究．采用Ｘ射线衍射（ＸＲＤ）、电感偶合等离子体光源的原子发射光谱（ＩＣＰ）对α－Ｆｅ_２Ｏ_３电极在第一、二次循环中不同时段进行了跟踪分析测量．实验结果揭示： α－Ｆｅ_２Ｏ_３能进行少量锂化;大量的α－Ｆｅ_２Ｏ_３在第一次放电和充电后反应生成Ｆｅ_３Ｏ_４;之后,Ｆｅ_３Ｏ_４的锂化行为不可避免地为Ｆｅ的析出、氧化反应所限制,但在用ＫＯＨ作电解质溶液的对比实验时发现：α－Ｆｅ_２Ｏ_３在ＬｉＯＨ溶液中的充放电行为与它在ＫＯＨ溶液中是不同的,主要表现为,１）在ＬｉＯＨ溶液中,锂化和Ｆｅ析出、氧化反应协调的结果是其充放电曲线平台高度比在同碱度 ＫＯＨ溶液中降低了 １００ ｍＶ左右, ２）与 Ｋ~（＋）对比, Ｌｉ~（＋）的插入反应促进了α－Ｆｅ_２Ｏ_３到Ｆｅ_３Ｏ_４的转化．     

（四甲基二硅撑）双（3－三甲硅基环戊二烯基）－四羰基二铁的反应性

标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２／（μ－ＣＯ）_２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ_２Ｃｌ、ＣｌＣＨ_２ＣＯＯＣ_２Ｈ_５和Ｐｈ_３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２Ｒ］_２（Ｒ：ＭｅＣＯ（１），ＰｈＣＯ（２），ＰｈＣＨ_２（３），ＣＨ_２ＣＯＯＣ_２Ｈ_５（４），Ｐｈ_３Ｓｎ（５），Ｉ（６））。Ａ在氯仿中与碘反应，得到Ｆｅ－Ｆｅ断裂的双铁碘化物，但在苯中与过量碘反应，则得到Ｆｅ－Ｉ－Ｆｅ桥联的离子型化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２Ｉ·Ｉ（７）。化合物６的晶体和分子结构经Ｘ射线衍射测定，６属单斜晶系，Ｐ２１／ｃ空间群，ａ＝１．７２１７（４）ｎｍ，ｂ＝０．７７５３（２）ｎｍ，Ｃ＝１．３６２９（７）ｎｍ，β＝１０３．８０（３）°，Ｖ＝１．７６７（２）ｎｍ３，Ｚ＝４，Ｄｃ＝１．６２９９·ｃｍ－１，最终偏差因子Ｒ＝０．０５４。     

对“三草酸合铁(Ⅲ)酸钾的制备”的改进

在Ｋ３［Ｆｅ（Ｃ２Ｏ４）３］·３Ｈ２Ｏ合成过程中,当草酸加入Ｈ２Ｏ２氧化ＦｅＣ２Ｏ４·２Ｈ２Ｏ产物制备Ｋ３［Ｆｅ（Ｃ２Ｏ４）３］·３Ｈ２Ｏ溶液时,原实验条件控制不严格,易发生草酸还原高铁的副反应而导致产品不纯。本文通过改进草酸加入方式和酸溶终了ｐＨ的控制,可降低副反应,提高产品质量。     

具有不同类型桥基的双核Cu(Ⅱ)-Schiff碱配合物的合成和晶体结构

合成了３个分别以Ｃ２Ｏ２－４（［Ｃｕ２（Ｌ１）２（ｏｘ）］，１），ＡｃＯ－（［Ｃｕ２（ＡｃＯ）（Ｌ２）２］ＢＦ４，２）和酚氧（［Ｃｕ２（Ｌ３）２］（ＣｌＯ４）２，３）为桥基的双核铜配合物，并测定了１的复配合物［Ｃｕ２（Ｌ１）２（ｏｘ）］·［Ｆｅ（ＯＨ）２（Ｈ２Ｏ）４］ＣｌＯ４·Ｈ２Ｏ（１′）及２和３的晶体结构．Ｘ射线衍射结果表明：１′，２和３分别属于Ｆｄｄｄ，Ｐ２１／ｃ和Ｐ２１／ｃ空间群．晶胞参数：［Ｃｕ２（Ｌ１）２（ｏｘ）］［Ｆｅ（ＯＨ）２（Ｈ２Ｏ）４］ＣｌＯ４·Ｈ２Ｏ，ａ＝２．４３９０（４）ｎｍ，ｂ＝３．０５３８（６）ｎｍ，ｃ＝１．８４９４（６）ｎｍ，α＝β＝γ＝９０．００°；２，ａ＝０．８４７（１）ｎｍ，ｂ＝２．６５４２（８）ｎｍ，ｃ＝１．４１００（６）ｎｍ，β＝９１．３４（６）°；３，ａ＝０．７６４６（３）ｎｍ，ｂ＝１．６９８３（３）ｎｍ，ｃ＝２．４４１７（３）ｎｍ，β＝９７．１１°     

等瓣置换反应的研究──手性簇合物［（η~5－MeO_2CC_5H_4）（CO）_2Mo］·［（η~5－MeO_2CC_5H_4）（CO）_2W］Fe（CO）_3（μ_3－S）的分子结构及晶体结构

用Ｘ射线衍射法测定了由η~５－ＭｅＯ_２ＣＣ_５Ｈ_４）（ＣＯ）_３ＭｏＮａ和［（η~５－ＭｅＯ_２ＣＣ_５Ｈ_４）（ＣＯ）_２Ｗ］Ｆｅ－（ＣＯ）_３Ｃｏ（Ｃｏ）_３（μ_３－Ｓ）的等瓣置换反应所生成的手性簇合物──［（η~５－ＭｅＯ_２ＣＣ_５Ｈ_４）（ＣＯ）_２Ｍｏ］－［（η~５－ＭｅＯ_２ＣＣ_５Ｈ_４）（ＣＯ）_２Ｗ］Ｆｅ（ＣＯ）_３（μ_３－Ｓ）的分子结构及晶体结构。晶体属Ｐ１空间群，晶胞参数α＝０．８７１６２（５）ｎｍ，ｂ＝０．７６２１８（４）ｎｍ，ｃ＝１．８７１１１（８）ｎｍ；α＝９４．１６４（４）°，β＝９７．９７９（２）°，γ＝９９．１０８（２）°，Ｚ＝２，μ＝５．９ｃｍ~（－１）。最终的一致性因子Ｒ＝０．０３６，Ｒｗ＝０．０３７．该簇合物含ＭｏＷＦｅＳ四面体簇核，其中Ｍｏ、Ｗ原子以１：１的比例无序地分占了四面体的２个顶点．     

α-Fe2O3在LiOH水溶液中的锂化行为

用循环伏安和红外光谱法对α－Ｆｅ２Ｏ３在室温ＬｉＯＨ溶液中的锂化行为进行研究,采用Ｘ射线衍射（ＸＲＤ）、电感偶合等离子体光源的原子发射光谱（ＩＣＰ）对α－Ｆｅ２Ｏ３电极在第一、二次循环中不同时段进行了跟踪分析测量。实验结果揭示：α－Ｆｅ２Ｏ３能进行少量锂化;大量的α－Ｆｅ２Ｏ３在第一次放电和充电后反应生成Ｆｅ３Ｏ４;之后,Ｆｅ３Ｏ４的锂化行不可避免地为Ｆｅ的析出,氧化反应所限制,但在用ＫＯＨ作电解     

α-Fe_2O_3掺杂对In_2O_3电导和气敏性能的影响

用化学共沉淀法制备了α－Ｆｅ２Ｏ３掺杂的Ｉｎ２Ｏ３纳米晶微粉,研究了α－Ｆｅ２Ｏ３掺杂对Ｉｎ２Ｏ３电导和气敏性能的影响．结果表明,α－Ｆｅ２Ｏ３和 Ｉｎ２Ｏ３间可形成有限固溶体Ｉｎ２－ｘＦｅｘＯ３（０≤ｘ≤０．４０）;Ｆｅ３＋对 Ｉｎ２Ｏ３晶格中Ｉｎ３＋格位的部分取代,大大增强了阴阳离子间的结合力,导致材料中氧空位Ｖｏｘ数骤降、自由电子的浓度变稀和电导下降．ｎ（Ｆｅ３＋）：ｎ（Ｉｎ３＋）＝５：５的共沉淀粉于 ８００℃下灼烧 ４ ｈ所得的 α－Ｆｅ２Ｏ３掺杂Ｉｎ２Ｏ３传感器元件,对 ４５μｍｏｌ·Ｌ－１Ｃ２Ｈ５ＯＨ的灵敏度达５４．０,为相同浓度干扰气体汽油的８倍多．     

三元体系Y（ClO_4）_3·3H_2O—B15C5—CH_3OH（25℃）的半

采用半微量相平衡方法研究了三元体系Ｙ（ＣｌＯ４）３·３Ｈ２Ｏ－Ｂ１５Ｃ５—ＣＨ３ＯＨ在２５℃的溶解度，测定了各饱和溶液的折光率．该体系在２５℃生成三种化学计量的配合物，其组成分别为：４Ｙ（ＣｌＯ４）３·３Ｂ１５Ｃ５·１２Ｈ２Ｏ·１２ＣＨ３ＯＨ（Ⅰ）、Ｙ（ＣｌＯ４）３·Ｂ１５Ｃ５·３Ｈ２Ｏ·１．５ＣＨ３ＯＨ（Ⅱ）与Ｙ（ＣｌＯ４）３·２Ｂ１５Ｃ５·３Ｈ２Ｏ·ＣＨ３ＯＨ（Ⅲ），其中配合物（Ⅰ）和（Ⅱ）是溶解不一致化合物．在甲醇溶剂中，分离制备了配合物（Ⅲ），在６９—７２℃下干燥得到配合物Ｙ（ＣｌＯ４）３·２Ｂ１５Ｃ５·３Ｈ２Ｏ．利用ＩＲ光谱、电导测量及Ｘ－射线衍射分析对配合物进行了表征．     

煤裂解过程中负载铁化学形态的变化

应用ＥＸＡＦＳ、ＸＡＮＥＳ和ＸＲＤ方法研究了褐煤中负载铁在裂解过程中化学形态的变化规律。结果表明，在载ＦｅＣｌ３．６Ｈ２Ｏ煤中，铁与煤表面碳－氧官能团发生强烈的相互作用。随热处理温度的升高，铁化学形态以如下顺序递变：高分散Ｆｅ－Ｏ／Ｃ络合物，超细ＦｅＯＯＨ，晶态Ｆｅ３Ｏ４，晶还原态铁（α－Ｆｅ，（Ｆｅ，Ｃ））《     

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.