纳米ZnO脱硫剂表面结构与室温脱除H2S性能的研究

采用均匀沉淀法制备纳米ZnO，经260 ℃，360 ℃，460 ℃和550 ℃焙烧制备的纳米ZnO均具有六方纤锌矿结构，平均粒径分别为14.3 nm，21.2 nm，24.1 nm和35.3 nm。通过TEM、TPR、XRD和XPS等技术对脱硫剂进行了表征。结果表明，纳米ZnO提高了对H₂S的室温去除率，室温脱除H₂S的活性时间是分析纯ZnO的近40倍；其脱硫性能随粒径增大，氧空位减少而下降，脱硫后高结合能的硫物种增多，硫取代晶格氧的趋势增大。说明粒径大小和氧空位是纳米ZnO室温脱硫的主要影响因素。纳米ZnO(14.3 nm)可直接将H₂S选择氧化为单质硫，尾气中未见SO₂产生。     

纳米晶态硼化钴的合成及其催化氨硼烷高效制氢

采用简单的煅烧工艺合成了纳米硼化钴(CoB)晶体,并首次研究了纳米CoB晶体在氨硼烷溶液水解制氢过程中的催化活性。研究发现,纳米CoB晶体具有较高的催化活性,在室温条件下其转换频率(TOF)为35.3 mol_H2·mol_cat^-1·min^-1,优于同等条件下贵金属Pt催化剂(TOF=29.3 mol_H2·mol_cat^-1·min^-1)。此外,循环测试8次后纳米硼化物晶体的催化制氢性能没有发生衰减。进一步研究发现CoB表面的Co⁰物种是催化制氢的活性位点,而表面的B物种位点能够有效辅助Co⁰位点实现协同催化氨硼烷制氢。     

纳米晶态硼化钴的合成及其催化氨硼烷高效制氢

采用简单的煅烧工艺合成了纳米硼化钴(CoB)晶体,并首次研究了纳米CoB晶体在氨硼烷溶液水解制氢过程中的催化活性。研究发现,纳米CoB晶体具有较高的催化活性,在室温条件下其转换频率(TOF)为35.3mol_H2·mol_cat^-1·min^-1,优于同等条件下贵金属Pt催化剂(TOF=29.3mol_H2·mol_cat^-1·min^-1)。此外,循环测试8次后纳米硼化物晶体的催化制氢性能没有发生衰减。进一步研究发现CoB表面的Co⁰物种是催化制氢的活性位点,而表面的B物种位点能够有效辅助Co⁰位点实现协同催化氨硼烷制氢。     

离子交换-双氧水氧化法制备纳米CeO2晶体

以99.995% Ce(NO₃)₃和强碱性阴离子交换树脂为原料，采用离子交换-双氧水氧化法合成制备出纳米CeO₂晶体。并就离子交换反应中的Ce³⁺浓度、树脂加入速度和离子交换温度及H₂O₂加入速度等条件对CeO₂粒径的影响进行了探讨，得出了离子交换-双氧水氧化法制备纳米CeO₂晶体的最佳工艺条件。FTIR、TEM分析表明，离子交换法无需对合成的Ce(OH)₃溶胶进行洗涤即可去除NO₃^-、CO₃^2-等阴离子杂质，并用H₂O₂将该溶胶氧化，经真空干燥可制得粒径分布均匀，平均晶粒尺寸约3 nm，高纯度的CeO₂粉体。     

1-异丙基-3-异丙烯基-1H-吡唑并[3,4-d]嘧啶-4-胺的合成、表征及抗肿瘤活性

以3-碘-1H-吡唑并[3,4-d]嘧啶-4-胺(2)为原料,经过N-烷基化、Suzuki偶联反应得到目标化合物1-异丙基-3-(异丙烯基)-1H-吡唑并[3,4-d]嘧啶-4-胺(1),两步反应总收率57.0 %。产物及中间体结构经₁^H NMR、_1³C NMR、ESI-MS以及X-射线单晶衍射进行表征。并对该Suzuki反应条件进行研究,确定最佳条件为：Pd(dppf)Cl₂的用量为n (Pd(dppf)Cl₂) : n (化合物3) = 0.06 : 1;物料比为n(异丙烯基硼酸): n(化合物3)= 1.6 : 1;反应溶剂为N,N-二甲基甲酰胺;反应温度为100 ℃;反应时间2 h,在最佳反应条件下,该Suzuki偶联反应收率达到68.2 %。体外抗肿瘤活性测试表明,产物(1)对MCF-7、A549、PC-3、HepG2和SGC-7901增殖均有明显的抑制活性,特别抑制MCF-7的IC₅₀值达到10.6 μmol?L_-1^。     

Phen-铜(II)-氨基酸配合物的合成、表征及其SOD活性

合成了3个新的SOD模拟配合物：[Cu(Phen)(L-Gln)(H₂O)]Cl·2H₂O (1)、[Cu(Phen)(L-Ala)(H₂O)]Cl·4H₂O (2)、[Cu(Phen)(L-Thr)(H₂O)]Cl·2H₂O (3) [Phen(1，10-邻菲咯啉)、L-Gln(谷氨酰胺)、L-Ala(丙氨酸)、L-Thr(苏氨酸)]。用元素分析、摩尔电导、红外光谱、紫外-可见光谱对配合物进行了表征。用X-射线衍射对配合物[Cu(Phen)(L-Gln)(H₂O)]Cl·2H₂O的晶体结构进行了测定。用氯化硝基四氮唑蓝(NBT)光还原法对这3个配合物催化歧化超氧阴离子自由基(O₂^{- ·})的能力进行了测定。结果表明：这些配合物具有较高的SOD活性， 催化速率常数K_Q分别为1.58 × 10⁷ mol^-1·L·s^-1、5.65 × 10⁷ mol^-1·L·s^-1、0.83 × 10⁷ mol^-1·L·s^-1。     

不同形貌纳米CoWO4的水热法制备及气敏性能

以Co（NO₃）₂·6H₂O、Na₂WO₄·2H₂O为主要原料,去离子水为溶剂,利用水热法在不同条件下制备了一系列的纳米CoWO₄,用XRD、TEM和比表面分析仪对产品的物相、形貌和比表面积进行了表征。较系统地探讨了水热条件（反应混合物pH值、反应时间、反应温度等）对产物物相和形貌的影响,并研究了不同形貌产品对甲醛、乙醇、氨气、苯和丙酮等的敏感性能。结果表明：水热条件对产品的物相和形貌有影响,在不同水热条件下,可成功制备CoWO₄纳米颗粒、纳米立方体及纳米棒;以纳米颗粒、纳米立方体及纳米棒样品制成的气敏元件对被试气体有不同程度的响应,其中以纳米颗粒为基的元件在210℃对1000μL·L^-1NH₃灵敏度为3.3。     

自组装的四(4-N,N-二乙胺基苯基)卟啉/多酸(钠)有机/无机复合薄膜及其气敏性质

选择Keggin型12-磷钨酸（TPA）及其钠盐（NaTP）水溶液为亚相,用四（4-N,N-二乙胺基苯基）卟啉化合物（H₂TNPP）自组装膜为功能模板,釆用低成本的QLS法成功制备了2种新型有机/无机复合材料：H₂TNPP/TPA,H₂TNPP/NaTP QLS薄膜。薄膜结构、形貌及半导体性质测试发现：H₂TNPP分子在H₂TNPP/TPA,H₂TNPP/NaTP复合膜中均采取H-聚集模式,TPA亚相上H-聚集程度更大。而在纯H₂TNPP膜中其为J-聚集模式。3种薄膜表面均为纳米颗粒形貌,以H₂TNPP/NaTP膜表面颗粒均一,颗粒尺寸最小（~60 nm）,H₂TNPP/TPA膜表面缺陷较多,颗粒尺寸最大（~150 nm）。薄膜导电性依次为H₂TNPP/NaTP（3.00×10^-5 S·cm^-1）>H₂TNPP/TPA（2.49×10^-5 S·cm^-1）>H₂TNPP膜（1.53×10^-5 S·cm^-1）。常温气敏测试发现：3种薄膜在30 s内对浓度小于1.88 mg·m^-3的NO₂气体都有响应,灵敏度依次为H₂TNPP/NaTP（43%）>H₂TNPP膜（16%）>H₂TNPP/TPA（4.5%）。具有最小颗粒尺寸和最高导电性的H₂TNPP/NaTP复合薄膜具有最高的灵敏度,并且对NO₂检测限低至0.094 mg·m^-3。显示出了非常高的实际应用价值。本研究为制备低成本、高灵敏度、环境友好的快速室温NO₂气敏器件提供了一种新的策略。     

三维Cu-MOF对亚甲蓝的吸附和光催化降解及其机理

本文报道了[Cu₃(ppda)₃(tib)₂(H₂O)₄]·6H₂O (Cu-MOF)的合成、结构、吸附和光催化降解性能。在Cu-MOF中，1，4-苯二乙酸(H₂ppda)和1，3，5-三(1-咪唑基)苯(tib)配体交替连接Cu离子形成二维层，层与层之间通过trans-ppda^2-相互穿插形成稳定的三维结构。Cu-MOF对亚甲蓝(MB)的催化效率为97%，最高反应速率常数为0.019 7 min^-1。光催化降解机理：在光的激发下，催化剂表面的光生电子和空穴对发生分离，并与O₂、H₂O、H₂O₂反应生成活性物质，将染料降解为CO₂和H₂O。在MB溶液中加入NaCl (200 g·L^-1)后，Cu-MOF的吸附量有所提升(87.23 mg·g^-1)，准二级动力学模型和Langmuir等温线模型的实验数据拟合程度较好，该吸附的主要过程为单层化学吸附。     

碳酸盐共沉淀法可控制备超高倍率锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2

采用碳酸盐共沉淀法通过调节NH₃·H₂O用量来实现可控制备超高倍率纳米结构LiNi_1/3Co_1/3Mn_1/3O₂正极材料。NH₃·H₂O用量会对颗粒的形貌、粒径、晶体结构以及材料电化学性能产生较大的影响。X射线衍射（XRD）分析和扫描电镜（SEM）结果表明,随着NH₃·H₂O用量的降低,一次颗粒形貌由纳米片状逐渐过渡到纳米球状,且n_NH3·H2O：（n_Ni+n_Co+n_Mn）=1：2样品晶体层状结构最完善、Li⁺/Ni²⁺阳离子混排程度最低。电化学性能测试结果也证实了n_NH3·H2O：（n_Ni+n_Co+n_Mn）=1：2样品具有最优异的循环稳定性和超高倍率性能。具体而言,在2.7~4.3 V,1C下循环300次后的放电比容量为119 mAh·g^-1,容量保持率为81%,中值电压基本无衰减（保持率为97%）。在100C（18 Ah·g^-1）的超高倍率下,放电比容量还能达到56 mAh·g^-1,具有应用于高功率型锂离子电池的前景。此NH₃·H₂O比例值对于共沉淀法制备其他高倍率、高容量的正/负极氧化物材料具有一定的工艺参考价值。     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

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.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.