两个基于四氮唑衍生物的配位聚合物的合成

在水热条件下,5-(4-吡啶基)四氮唑(4-PTZ)分别与氯化锌和氯化镉反应,得到2个基于此配体的配位聚合物,它们的分子式分别为{[Zn(4-PTZ)₂Cl₂]·4H₂O}n(1)和{[Cd₃(4-PTZ)₂(H₂O)₂Cl₆]·3H₂O}n(2),且表现出不同的配位模式.这2个化合物均结晶在单斜晶系,化合物1的晶胞参数分别为:a=0.69175(8)nm;b=2.6688(3)nm;c=1.12266(12)nm;β=93.5350(10)°;V=2.0687(4)nm³;Z=4;R₁=0.0318(I>2σ(I));wR₂=0.0829;空间群为P2₁/n.化合物2的晶胞参数分别为:a=1.89713(13)nm;b=1.05579(7)nm;c=1.44649(10)nm;β=102.4890(10)°;V=2.8287(3)nm³;Z=4;R₁=0.0262(I>2σ(I));wR₂=0.1343;空间群为C₂/c.通过元素分析、红外光谱分析和热重分析对该化合物进行了表征,另外荧光测定结果显示化合物1和2的固态粉末在室温下均表现出较强的紫外荧光发射特性.     

碳纳米管负载的Pd-Ag-Sn催化剂对甲酸的电氧化

采用硼氢化钠还原的方法合成了碳纳米管负载的钯基纳米催化剂（Pd/CNT,Pd₇Ag₃/CNT,Pd₇Sn₂/CNT,Pd₇Ag₁Sn₂/CNT,Pd₇Ag₂Sn₂/CNT和Pd₇Ag₃Sn₂/CNT）。通过XRD,TEM和XPS对其进行了表征,结果表明,相比Pd/CNT和Pd-Ag（或Pd-Sn）催化剂的纳米颗粒,Pd-Ag-Sn催化剂展现出了更小的平均颗粒尺寸（2.3 nm）。此外,还通过循环伏安（CV）和计时电流法（CA）测试了这些催化剂对甲酸氧化的电活性,在酸碱介质中,Pd-Ag-Sn/CNT对甲酸氧化都表现出了更高的电流密度。其中,Pd₇Ag₂Sn₂/CNT催化剂在酸碱介质中的电流密度分别是108.8和211.3 mA·cm^-2,相应的Pd质量电流密度高达1 364和2 640 mA·mg^-1,远远高于商业Pd/C,表明Pd-Ag-Sn/CNT催化剂对甲酸氧化表现出了极好的电催化活性。     

含有磺胺的多金属氧酸盐的合成及抑制前列腺癌细胞PC-3M作用的研究

合成了(C₆H₉N₂O₂S)₅HP₂Mo₁₈O₆₂•15H₂O (SPOM-1)和(C₆H₉N₂O₂S)H₈P₂Mo₁₅V₃O₆₂•8H₂O (SPOM-2)两种新的含有磺胺的多金属氧酸盐, 通过元素分析、IR光谱对其结构进行了表征. 在人雄激素非依赖性前列腺癌细胞系PC-3M内, 对合成的多金属氧酸盐进行了抗肿瘤活性的研究. 研究发现, SPOM-1, SPOM-2在体外能明显抑制前列腺癌PC-3M细胞, 并呈一定的量效关系, EC₅₀分别为38, 11 g•mL^－1; 治疗指数(TI)分别为12.07, 26.82; SPOM-2的抗前列腺癌PC-3M细胞活性大于SPOM-1.     

含苯并咪唑三足配体的金属配位化合物的合成及对碘的吸附性能

通过溶剂热法合成了2种新型金属配位化合物[Co₃(L1)₂Cl₆]_n (1)和{[Cu(L1)(SO₄)]·2CH₃OH}_n (2)，其中L1=2，2''，2″-三(1-苯并咪唑基)乙基胺，是一种中性苯并咪唑三足有机配体。单晶X射线衍射分析表明化合物1是一维链状结构、化合物2是三维结构；红外光谱和粉末X射线衍射表征证实化合物1和2的纯度较高。热重分析表明化合物1和2是耐热性的材料。碘吸附实验表明，2个化合物对环己烷溶液中的碘和气态碘都有很高的捕获性能且具有良好的循环利用性。同时，它们的吸附动力学最符合准二级模型，吸附过程以化学吸附为主。吸附机理研究进一步表明化合物的结构中含有苯、氮杂环等活性基团，间接增加了与碘的吸附位点，提高了与碘的化学反应性和碘的去除率。     

微乳液法制备纳米草酸钆的热解机理的研究

Gd₂O₃∶Tb³⁺ luminescent nanoparticles were prepared by the thermal decomposition of the nanosized oxlate prepared in the reverse microemulsions based on triton X-100 / n-hexyl alcohol, n-octane, and water. From TG-DTA, XRD and FTIR analyses, the mechanism of thermal decomposition of the nanosized oxalate precursor is suggested as follows: Gd₂(C₂O₄)₃·10H₂O → Gd₂(C₂O₄)₃ + 10H₂O, Gd₂(C₂O₄)₃ → Gd₂O₂(CO₃) + 3CO +2CO₂, Gd₂O₂(CO₃) → Gd₂O₃ + CO₂. The kinetic parameters of thermal decomposition reaction-activation energy E of stage 2 and 3 are 194.6 kJ·mol^-1, 110.9 kJ·mol^-1, respectively, using Ozawa method. And the reaction order n is 2.9 and 0.43, respectively, according to the TG curves.     

二丁基硫醚的合成及其萃取分离钯、铂的研究

用Na₂S·9H₂O和1-溴丁烷合成了二丁基硫醚(简写为M)。以二丁基硫醚为萃取剂进行了钯、铂萃取分离的研究,并采用正交实验,得出了钯、铂分离的最佳条件为c_M=0.344 mol·L^-1,O/A=1∶1,t=6 min,c_H⁺=2 mol·L^-1。测得二丁基硫醚萃取钯的容量大于17 g·L^{-1相似文献}   

基于席夫碱分隔配体的Cu-Tb单分子磁体的阴离子调控

基于席夫碱分隔配体H₂vanophen（1,2-苯二胺缩邻香草醛）,通过引入不同的阴离子,构筑了3个Cu-Tb基金属配合物[Cu₂（vanophen）₂TbCl₂（MeOH）₂]Cl·3MeOH（1）、[Cu₂（vanophen）₂TbCl₂（MeOH）₂]（TCNQ）_1.5·2MeOH（2）和[Cu₂（vanophen）₂Tb₂（N₃）₆]·2MeOH（3）（TCNQ=7,7,8,8-四氰基对苯二醌二甲烷）,并详细研究了它们的结构和磁性。除了抗衡阴离子外,配合物1和2具有非常相似的[CuTbCu]三核结构;其中Cu（Ⅱ）离子处于席夫碱配体中的[N₂O₂]配位口袋中,而Tb（Ⅲ）离子则和配体中的[O₄]配位口袋中的全部或部分O原子配位。对应于一个三核基元,配合物1中的抗衡阴离子为一个Cl^-离子,而配合物2中的抗衡阴离子是一个TCNQ^-0.5阴离子及半个TCNQ^-阴离子。配合物3是由end-end及end-on叠氮桥联2个[CuTb]单元形成的四核[CuTb]2配合物。磁性研究表明,三核配合物1和2均为场致的单分子磁体而配合物3为零场单分子磁体,其中配合物1和3的能垒分别为（11.1±0.3） cm^-1和（20.2±0.3） cm^-1。相比于配合物1,配合物2具有更低的能垒,这可能源于其中的阴离子自由基和三核[CuTbCu]基元之间的弱的磁相互作用。     

多孔铝合金的孔隙率

建立了两种孔形(球形,多角形)多孔铝合金总孔隙率(Pr_c)的物理模型,实验值(Pr_e)与理论计算值((Pr_c)符合良好.多孔铝合金的总孔隙率(Pr_c)由填料颗粒堆积造成的孔隙率(Pr_堆积)、液-固两相不浸润所致的附加孔隙率(Pr_附加)和凝固收缩引起的孔隙率(Pr_凝固)组成.Pr_堆积是Pr _c的主部,Pr_附加对Pr_c的贡献虽小,但却是成功制备多孔铝合金的关键.     

含吡咯环的缩氨基硫脲席夫碱镍、铜配合物的晶体结构及与DNA的相互作用

合成并通过单晶衍射、元素分析及红外光谱表征了配合物[Ni（L¹）₂]·2DMF （1）,[Cu（L¹）₂]·THF·0.25MeOH·2.25H₂O（2）, [Ni（L²）₂]·2MeOH（3）和[Cu（L²）₂]·2EtOH （4）的结构（HL¹：5-甲酰基-3,4-二甲基-吡咯-2-甲酸乙酯缩硫代氨基脲,HL²：5-甲酰基-2,4-二甲基-吡咯-3-甲酸乙酯缩4-异丙基氨基硫脲）。单晶衍射结果表明,除溶剂分子不同外,配合物1~4的结构相似。每个配合物的中心金属离子分别与来自2个阴离子L^-配体的N₂S₂电子供体配位,采取扭曲的平面正方形配位构型。荧光光谱结果表明,配合物与DNA的相互作用强于其配体。     

水对苯硼酸参与的偶联反应的促进作用

水;离子液体;PEG;苯硼酸;Suzuki偶联反应;Suzuki-Type偶联反应     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.