氯气的制取与性质实验绿色化设计

针对氯气有毒及其与金属反应易于泄露等实验不足,设计了氯气制取、氯气与金属反应和氯水成分探究的全封闭实验。其中,氯气与金属的反应采用原位电加热的方式,加热速度快,金属在氯气中的燃烧现象明显,且能快速识别产物,有效地消除了因加热带来的氯气泄露问题;氯水成分的探究是通过青霉素瓶在封闭条件下进行的。整个实验仪器常规,装置简单,药品用量少,操作容易,现象明显,安全无污染,非常适合课堂演示。     

数字化实验探究次氯酸光照分解反应

针对教材和文献中次氯酸光解实验的不足之处,利用数字化实验从光照条件、氯水浓度、传感器、实验表征等方面探究次氯酸光解实验成功的关键因素,测得溶解氧、pH和氯离子浓度的数据为支持多重表征次氯酸光解过程,帮助学生通过实验促进对次氯酸分解反应的理解,发展学生证据推理与模型认知、实验探究与创新意识等化学学科核心素养。     

氢硫酸的新法制备及其全封闭性质实验

氢硫酸必须现用现制。即便如此,部分被氧化仍是不可避免的。细心的实验者会观察到此时氢硫酸溶液外观轻微浑浊,清晰度较之其它溶液要差。演示被氯水氧化实验,前后浑浊现象对比不够明显。鉴于H2S的强还原性、毒性和恶臭气味以及由此而造成的环境污染,可否制得能长期保存而又可多次使用的氢硫酸呢?     

硫化学性质演示实验的设计

演示实验是化学中最有效的教学手段,它除了符合化学实验的基本要求外,还应具备演示实验特有的直观性和示范性。课堂演示实验应保证全班同学能清楚地观察实验的全部过程,同时教师在实验中应始终注意化学反应生成毒物的处理及其它有关的安全教育。高中教科书（注1）中硫化学性质一节的课堂演示实验,在教学过程中演示现象观察不理想且示范性差（如生成SO2、H2S毒性大,没有及时处理）,我们重新设计了以下装置进行演示。     

氯水光照分解实验改进

新编高级中学化学课本(必修)第一册[实验1-6]介绍的氯水光照分解实验(同以前各版本相同,是将无支管的盛满氯水的圆底烧翻倒立在盛氯水的水槽内。)由于氯水与空气大贰积接触,氯气逸出污染实验环境且氯水易失效;不便于验证分解产物,使用新制氯水进行实验时即使在日光直射下也不能在45分钟内有明显现象。实验效果不够理想。     

氯水和溴化钾、碘化钾溶液反应现象的探讨

对氯水与碘化钾溶液、溴化钾溶液反应出现的现象通过实验进行了探讨,分析了氯水和KI溶液反应后的溶液用CCl4萃取生成的碘时出现异常现象的原因,提出了做好氯水与碘化钾溶液反应实验的方法。     

氯水性质检验的微型实验设计

采用以双通管为主体的复合微型实验装置,4 min 内完成了氯水的制备、氯水颜色的观察、氯水的萃取、氯气与水反应产物H+与Cl-的检验、氯水漂白性的实验。     

卤素单质水溶液的颜色研究

在卤素单质间置换反应实验环境下,将氯水、溴水、碘水从有色饱和溶液逐步稀释到无色“溶液”,观察到一系列不同浓度下氯水、溴水、碘水的颜色。指出了卤素单质颜色的变化趋势、主要显色、相互共色等问题。     

多现象演示实验设计：谈用“组合设计法”设计氨的喷泉,喷烟,发光与发声实验

“多现象演示实验”就是一个演示实验出现几种可观察的现象,例如,在做ＮＨ３的喷泉实验时,伴随发光和喷烟现象。多现象演示实验数目不多,大多集中在颜色的变化范围内,即同一演示实验出现不同颜色。笔者查阅了有关国内外文献［１,２］,结合自己的实践,总结了采用组合设计法来设计多现象演示实验。１　组合设计法的思路顾名思义,就是将产生单一实验现象的装置,通过改进组合到同一演示实验装置中。现以两个实验来说明。ＮＨ３的喷泉喷烟实验。将ＮＨ３溶于水的喷泉实验装置（如下图Ⅰ）跟ＮＨ３与ＨＣｌ反应出现白烟实验装置（如下图…     

“卤素活动性比较”演示实验的改进

高中化学(甲种本)第一册第24页和高中化学(乙种本)上册第18页都有“卤素各单质的活动性比较”的两个演示实验,用来说明氯能置换溴和碘及溴能置换碘。这两个实验操作并不复杂,效果一般也较明显,但教师必须在课前预备好新制的氯水和溴水,否则实验效果就有问题;同时,由于溴和碘在水中的溶解度小,所以只好选用汽油作溶剂才易于观察比较,这样所观察到的并不是单质的嗅和碘,而是它们的溶液。     

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.     

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.     

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.