纳米TiO2微胶粒的光化应制备机理及量子尺寸效应

研究了由水相Ｔｉ＾３＋制备纳米极Ｔｉ＾Ｏ２微胶粒的光化反应机理及反应动力学，给出反应速率方程。讨论了ＴｉＯ２微胶粒的量子尺寸效应，经电镜测试ＴｉＯ２粒子的直径为１５－２５ｎｍ。反应过程中由气相色谱仪监测生成物Ｈ２。     

缺陷TiO2(110)表面吸附NO从头算研究

应用量子化学从头算方法对ＮＯ在ＴｉＯ２表面发生吸附的四种吸附模型进行了榴型优化，能量计算及Ｍｕｌｌｉｋｅｎ布居分析。计算结果表明，吸附模型Ｍ２－２是ＮＯ在ＴｉＯ２表面发生吸附分解最为有利的模型。据此提出了ＮＯ在ＴｉＯ２表面吸附分解形成Ｎ２Ｏ的可能机理，认为吸附ＮＯ发生该分解反应的反应势垒较自由ＮＯ大大降低，从而催化该反应的发生。该机理与实验的推测一致。     

α－Ti（HPO_4）_2·H_2O的制备方法研究

本文介绍了一种快速制备α－Ｔｉ（ＨＰＯ４）２·Ｈ２Ｏ晶体的新方法，该法以硫酸钛为原料，先制得稳定的Ｔｉ（Ｏ２）ＯＨ（Ｈ２Ｏ）＋４配离子溶液，将其加入磷酸溶液后，加热使Ｔｉ（Ｏ２）ＯＨ（Ｈ２Ｏ）＋４分解，逐步释放出钛与磷酸反应，在２小时内制得α－Ｔｉ（ＨＰＯ４）２·Ｈ２Ｏ。在实验温度１２０－１５５℃范围内，此法几乎不受温度和时间的影响。     

SO_4~（2－）－TiO_2－Hβ－Al_2O_3催化剂的制备及催化性能研究

以Ｈβ沸石为基础，通过ＴｉＯ_２改性及硫酸铵处理制备了ＳＯ－ＴｉＯ_２－Ｈβ－Ａｌ_２Ｏ_３催化剂，并由ＸＲＤ、ＸＰＳ、ＮＨ_３－ＴＰＤ、ＦＴＩＲ及化学吸附等手段考察了不同焙烧温度对该催化剂表面性质、酸性及催化性能的影响。结果表明：适宜的焙烧温度使ＳＯ－ＴｉＯ２－Ｈβ－Ａｌ２Ｏ３的酸量大幅度增加，强酸比例增大，并产生部分增强酸中心。高强度的酸性中心中，以Ｌ酸中心为主；５５０℃焙烧的样品能使沸石表面上ＳＯ与ＴｉＯ_２间发生较强的相互作用，高温焙烧则使浓度下降；该催化剂明显促进了丙烯与异丙醇的醚化反应，丙烯转化率由８．０％增高到１５．９％。关键词     

α—Ti（HPO4）2·H2O的制备方法研究

本文介绍了一种快速制备α－Ｔｉ（ＨＰＯ４）２·Ｈ２Ｏ晶体的新方法，该法以硫酸钛为原料，先制得稳定的Ｔｉ（Ｏ２）ＯＨ（Ｈ２Ｏ４）４＾＋配离子溶液，将其加入磷酸溶液后，加热使Ｔｉ（Ｏ２）ＯＨ（Ｈ２Ｏ）４＾＋分解，逐步释放出钛与磷酸反应，在２小时内制得α－Ｔｉ（ＨＰＯ４）２·Ｈ２Ｏ。在实验温度１２０－１５５℃范围内，此法几乎不受温度和时间的影响。     

NO^—2离子的光催化反应研究（Ⅱ）

研究了ＮＯ＾－２离子在ＴｉＯ２表面的光催化反应,结果表明,体系ｐＨ值升高及Ｃｒ,Ｃｌ＾－,ＳＯ＾２－４离了的加入均对ＮＯ＾－２离子在ＴｉＯ２表面的暗态吸附产生抑制作用,而ＮＯ＾－２在ＴｉＯ２表面的光照反应转化率则随ｐＨ值的升高出现先减小后增大的总体变化趋势。     

TiO2光谱化反应及其在废水处理中的应用

ＴｉＯ多相光催化能利用太阳能有效降低多种对环境有害的污染物，使有害物质矿化为ＣＯ２、Ｈ２Ｏ及其它无机小分子物质。本文综述了ＴｉＯ２光催化的机理，提高光催化能力的途径，多种具有代表性污染物的光催化降解处理方法，以及目前尚存在的一些问题，扼要介绍了近年来ＴｉＯ２ｚ光催化反应及其在废水处理中应用的研究进展及应用前景。     

添加非金属元素Si对固体超强酸SO_4~(2-)/TiO_2的改性研究

采用共沉淀法引入Ｓｉ对ＳＯ２－４／ＴｉＯ２进行改性，制得了ＳＯ２－４／Ｔｉ－Ｓｉ－Ｏ系列固体超强酸，试样经ＩＲ、ＳＥＭ、ＸＲＤ表征和低温正戊烷异构化活性测试，发现超强酸中心是硫酸根离子与金属原子Ｔｉ结合形成的双配位螯合结构，在超强酸性的样品中ＴｉＯ２均呈锐钛矿晶型。引入Ｓｉ仅迟滞ＴｉＯ２晶化过程，控制Ｓｉ在ＳＯ２－４／Ｔｉ－Ｓｉ－Ｏ体系中的含量可以有效调节固体超强酸的酸性，并提高正戊烷异构化反应的选择性。     

低温降解二氯甲烷的TiO_2－SO_4~（2－）催化剂研究

研制了硫酸化氧化钛催化剂（表示为ＴｉＯ_２－ＳＯ_４~（２－）），实验表明在低于３００℃的反应温度下，它能有效地降解二氯甲烷（浓度为４２．８μｍｏｌ／Ｌ），如在２７５℃，二氯甲烷的转化率达１００％，降解产物为ＣＯ、ＣＯ_２和ＨＣｌ．该催化剂含２％硫酸根，氨的吸附量为每克催化剂３．４ｍｍｏｌ．与未经硫酸化处理的ＴｉＯ_２对比，硫酸化后的催化活性显著提高，表明二氯甲烷降解反应发生在固体酸的酸性活性中心上．水汽的存在明显降低了催化活性，提高了反应活化能．在ＴｉＯ_２－ＳＯ_４~（２－）上负载ＣｕＯ后可显著提高降解产物中二氧化碳的选择性．     

载钛中孔二氧化硅分子筛的光催化性能研究

分别 以单一 Ｔｉ Ｏ２ 纳米粒 子及不 同 Ｔｉ Ｏ２ 覆 盖率的中 孔分 子筛（ Ｔｉ Ｏ２／ Ｈ Ｍ Ｓ） 和微 孔分 子筛（ Ｔｉ Ｏ２／ Ｎａ Ｙ） 为光催 化剂,以２ ,４ ,６三氯苯 酚（ Ｔ Ｃ Ｐ） 为 降解对象 ,考察了 两类分子 筛担 载 Ｔｉ Ｏ２ 的光催化性 能． 结 果表明 ： 在钛 含量相 同的 条 件下 , Ｔｉ Ｏ２／ Ｈ Ｍ Ｓ 的光 催 化活 性 高于 Ｔｉ Ｏ２／ Ｎａ Ｙ 和 单一 Ｔｉ Ｏ２ 的光催 化活性; Ｔｉ Ｏ２ 负载量 较低时 , Ｔｉ Ｏ２／ Ｈ Ｍ Ｓ 即可 显示 有高 的光 催化 活性, 且其 光催 化活性随着 中孔分 子筛孔径 的增大而 升高     

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.