锌(Ⅱ)配合物的超分子设计及对甲醇蒸气的吸附性能

采用饱和蒸气扩散技术, 将2,4-二羟基苯甲醛缩异烟酰腙(H₂dhbi)配体分别与Zn(ClO₄)₂·6H₂O和Zn(NO₃)₂·6H₂O进行配位作用, 得到2种不同配位模式的金属-有机框架材料[(dhbi)₂Zn₂·8H₂O]_n(1)和{[(dhbi)₂(H₂O)₂Zn₂]·4DMF]}_n(2). 利用X射线单晶衍射、 热分析技术(TG-DTA)和X射线粉末衍射(PXRD)等方法进行了结构表征. 进一步将配位聚合物1和2用于对甲醇分子的吸附性能研究, 结果表明, 化合物1是一种理想的微孔材料, 其对甲醇分子的吸附能力为化合物2的近5倍, 采用PLATON对材料的孔隙体积进行计算得到化合物1和2的孔隙率分别为38.2%和5.5%.     

草酰胺功能化的荧光阴离子骨架及其对亚甲基蓝的选择性吸附

由于对人类和环境的严重威胁,染料的吸附已经引起研究工作者的广泛关注。 本论文中利用四齿配体5,5'-[oxalylbis(azanediyl)]diisophthalic acid(H₄L)成功地合成出了草酰胺功能化的阴离子骨架材料{[(CH₃)₂NH₂]₂(CdL)}·x(Solvent)(1)。 单晶X射线衍射分析表明化合物1具有二重穿插的三维骨架,(3,3,4)-连接的新拓扑网络结构和{8³}₂{8⁶}的点(施莱夫利)符号。 更有趣的是,它不仅对亚甲基蓝呈现出选择性的吸附行为,而且在可见光区具有荧光发光性质。     

二维钨-钒簇聚物[Cu(en)2]2·[VⅤO44{Cu(en)2(H2O)}2]·3H2O的合成与表征

采用水热法合成了一个钨-钒簇聚物[Cu(en)₂]₂[V^Ⅴ{Cu(en)₂(H₂O)}₂]·3H₂O(1, en=乙二胺), 并通过X射线单晶衍射、 元素分析、 傅里叶变换红外光谱、 X射线粉末衍射、 热重分析、 价键计算、 X射线光电子能谱、 电子顺磁共振和磁性分析对其结构和性能进行了表征. 结果表明, 化合物1是以双支撑的四帽Keggin结构 [(V^ⅤO₄){Cu(en)₂(H₂O)}₂]^4- 钨-钒簇合物阴离子为基本结构单元, 与4个[Cu(en)₂]²⁺配合物阳离子以共价键和弱键相连接形成二维层状结构, 相邻层又通过氢键连接成三维超分子网络. 研究了化合物1的磁性及光催化降解罗丹明B的活性.     

基于2-氨基吡啶的两个簇基超分子化合物的合成、结构及催化性能

以磷钼酸、2-氨基吡啶、五氧化二钒、氯化锌和氯化镍等为主要原料,采用水热方法合成了2个簇基超分子化合物[H₃PMo₁₂O₄₀]₂[C₅H₆N₂]₆(1)和[H₂PMo₁₂V₂O₄₂][C₅H₆N₂]₅·3H₂O(2)(C₅H₆N₂=2-氨基吡啶).通过元素分析、红外光谱、紫外-可见光谱、X射线光电子能谱、热重分析、X射线单晶衍射及X射线粉末衍射等手段对化合物进行了结构表征.结构分析显示,簇单元不同的2个超分子化合物以各自独特的堆积方式形成三维超分子网络.利用苯乙烯的环氧化反应研究了2个化合物的催化性能.     

铜配合物修饰的Dawson型钨磷酸盐的合成、晶体结构和催化性能

在水热条件下,Cu(Ⅱ)-H₂biim配合物与Dawson型钨磷酸盐构筑了1个无机-有机杂化化合物[Cu(H₂biim)₂(H₂O)][{Cu(H₂biim)₂}₂(P₂W₁₈O₆₂)]·11H₂O(1)(H₂biim=2,2'-联咪唑)。 通过单晶X射线衍射、红外光谱(IR)、X射线粉末衍射(XRD)、元素分析、电化学分析等技术手段对其进行了表征。 结构分析表明,在化合物1分子中,[P₂W₁₈O₆₂]^6-单元作为双齿配体与2个Cu²⁺离子配位形成双支撑的杂多阴离子[{Cu(H₂biim)₂}₂(P₂W₁₈O₆₂)]^2-,在其外部有1个游离的[Cu(H₂biim)₂(H₂O)]²⁺ 和11个H₂O分子。 H₂biim分子与杂多阴离子/H₂O分子间存在氢键,通过氢键、静电和π-π堆积作用,进一步构成具有3D结构的晶体材料。 该晶体化合物对H₂O₂和NaNO₂的还原具有良好的电催化作用;同时,作为酸催化剂用于合成环己酮乙二醇缩酮反应,催化活性高,可重复使用。     

Mn(II)-Fe(II)-MCF的制备及催化性能

以改性玉米苞叶纤维为载体(MCF),负载Mn(II)和Fe(II)制备了Mn(II)-Fe(II)-MCF复合材料,催化H₂O₂氧化水中染料。通过傅立叶变换红外/近红外成像系统和扫描电子显微镜对其结构和形貌进行表征。实验结果表明:当染料浓度为10 mg·L^-1,Mn(II)-Fe(II)-MCF用量为4 g·L^-1,H₂O₂初始浓度为1.56 mmol·L^-1,Mn(II)-Fe(II)-MCF对四种染料的催化效率明显不同。阳离子蓝X-GRRL(CBX-GRRL)降解效果最好,其次是甲基橙(MO)、次甲基蓝(MB)和罗丹明B(RhB)。对染料的氧化反应进行动力学分析,MO的降解反应为二级反应,CBX-GRRL、MB和RhB的降解反应均为一级反应。Mn(II)-Fe(II)-MCF适合催化氧化偶氮染料废水。     

基于Keggin型杂多酸的无机-有机杂化物的合成和光催化活性

采用水热合成方法制备了2个基于Keggin型杂多酸的无机-有机杂化物, 化学式分别为{[Cu₂(4,4′- bipy)₄(H₂O)₄](SiMo₁₂O₄₀)·18H₂O}_n(1)和{[Cu₂(4,4′-bipy)₄(H₂O)₄](PMo₆W₆O₄₀)·18H₂O}_n(2)(bipy=bipyridine). 结构分析 表明2个化合物同构, Cu²⁺是六配位, 分别与4个4,4′-bipy上的N原子和2个水分子上的O原子结合, 形成 [Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺二维层状结构. 杂多阴离子通过静电与配位阳离子[Cu(4,4′-bipy)₂(H₂O)₂]_n²ⁿ⁺作用交叉排列在层间. 通过红外光谱、 粉末X射线衍射和固体紫外-可见漫反射光谱等对化合物的性质进行了表征. 研究了所合成化合物对水溶性染料亚甲基蓝的降解活性, 发现2种化合物对于亚甲基蓝均表现出显著的光降解活性, 并对它们的催化机理进行了讨论.     

新型混合价态钒锗簇合物的合成与表征

采用水热法合成了一个新型混合价态钒锗簇合物[Ge₆V₆^VV₉^ⅣO₄₂(OH)₆(H₂O)]·6(1,6-DAH)·21H₂O(1)(DAH=己二胺), 并通过X射线单晶衍射、 元素分析、 红外光谱、 热重分析、 价键计算、 X射线光电子能谱和磁性分析对其结构、 组成和性质进行了表征. X射线单晶衍射分析表明, 化合物1结晶属于六方晶系, R3c空间群, 晶胞参数 a=b=1.98418(6) nm, c=4.63450(3) nm; V=15.8015(12) nm³, Z=6. 该化合物中的[Ge₆V₆^VV₉^ⅣO₄₂(OH)₆(H₂O)]簇可看作由3个{Ge₂O₇}二聚体取代{V₁₈O₄₂}簇中的3个VO₅四方锥单元衍生而来. 价键计算和XPS分析表明, 化合物1中的钒原子处于混合价态. 磁性研究表明, 化合物1中存在弱的反铁磁相互作用.     

ZnO修饰提升花状BiOBr的可见光催化降解罗丹明B性能

以Bi(NO₃)₃·5H₂O、Zn(CH₃COO)₂·2H₂O和NaBr为前驱体,采用简单溶剂热法制备BiOBr/ZnO三维花状微纳米复合材料。采用X射线衍射、扫描电子显微镜、X射线光子能谱、N₂吸附-脱附、光致发光和电子顺磁共振等分析技术对其理化性质进行了表征。通过可见光催化降解罗丹明B(RhB)的实验测试了复合材料的光催化性能。结果表明ZnO含量为5%的BiOBr/ZnO光催化活性最优,RhB降解率在50 min后达到98.3%,其降解速率常数是纯ZnO和BiOBr的6.3倍和3.4倍,并且具有较高的稳定性。复合材料光催化性能增强的可能原因为ZnO的引入增强了可见光的吸收和光生载流子的电荷分离效率。     

CuSO4(ZnSO4)-CO(NH2)2-H2O三元体系在30℃时的等温溶度研究

报道了CuSO₄(ZnSO₄)-CO(NH₂)₂-H₂O两个三元体系在30℃时的等温溶度及饱和溶液的折光率,绘制了相应的溶度图和折光率-组成图.两个三元体系中分别形成了组成为CuSO₄·3CO(NH₂)₂·H₂O(异成分溶解)和ZnSO₄·CO(NH₂)·2H₂O(同成分溶解)的化合物,并通过元素分析、红外光谱、X射线粉末衍射及热分析对新相进行了表征.     

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.