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。     

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．     

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．     

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°     

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     

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））《     

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．     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

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%.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.