具有不同生色团的Pt（Ⅱ）配合物二阶非线性光学性质的DFT研究

采用密度泛函理论B3LYP／LANL2DZ方法,对实验合成的含有不同生色团的Pt（Ⅱ）配合物的电子性质和二阶非线性光学（NLO）效应进行计算分析。结果表明：配合物中二苯基啡咯啉部分表现出给电子的性质,金属Pt（Ⅱ）在配合物内起到平衡电荷的作用。对配合物lb～6b与配合物a进行比较发现,配合物1b-5b的βvec值比配合物a的成βvec值增大,而配合物6b的βvec值比配合物a的风值减小。7个配合物中前线分子轨道能级差越小的配合物,它的βvec值越大,同时配合物更深层占有轨道与空轨道之间的电子跃迁对二阶NLO效应有明显的贡献。     

12顶点[1-R-CB11-Me11]-碳硼烷氧化-还原过程二阶NLO效应的理论研究

采用密度泛函理论（DFT）对12顶点[1-R-CB₁₁-Me₁₁]^-碳硼烷的结构和二阶非线性光学（NLO）调节效应进行计算分析. 结果表明,C位连接的取代基R供、吸电子能力的不同以及分子发生可逆氧化-还原反应对分子构型有一定影响. 由自然键轨道（NBO）电荷和电子自旋密度分析可知,分子的氧化中心是碳硼笼,分子的氧化反应可导致碳硼笼部分给、受体特性发生改变. 氧化态分子的第一超极化率总有效值（β_tot）大于相应还原态分子,当C位取代基R为供电子基团（—NH₂）的分子时,氧化态与还原态的β_tot值变化最大. 这类分子的氧化-还原反应可以有效调节二阶NLO光学效应.     

六元碳环邻位对称取代的Λ-型分子非线性光学系数的计算

采用密度泛函理论(DFT)的BHandHLYP/6-31G*方法,对3类含有六元碳环的Λ-型分子的几何构型进行优化.在优化结构的基础上,结合有限场方法(FF)和含时密度泛函理论(TD-DFT)对分子的二阶非线性光学(NLO)活性及电子吸收光谱进行研究.结果表明,在拐点处环己烷的构象不同时,分子电荷分布、偶极矩、极化率、二阶NLO系数和电子吸收光谱等变化很小.以苯环为拐点片段的分子有所不同,当支链取代基R增大时,以苯环为拐点片段分子的极化率和二阶NLO系数增加明显.     

噻唑类二阶非线性光学活性分子的合成与性能

合成了4个以噻唑环为母体、含有Schiff碱结构的新型二阶非线性光学(NLO)活性分子,用红外光谱、紫外光谱、核磁共振光谱和元素分析确定了分子结构,用溶致变色法确定了二阶极化率. 分子中噻唑五元杂环和Schiff碱结构提高了NLO分子的热稳定性和透明性,噻唑的共轭芳香杂环非中心对称结构连接多个供、吸电子基团,提高了分子的二阶非线性系数. 结果表明,这些NLO分子的紫外吸收波长在350～415 nm之间,裂解温度均在300 ℃左右,二阶非线性光学系数β值达到1×10 -30 esu数量级,初步实现了"二阶非线性-透明性-热稳定性"综合性能优化的目标.     

基于偶氮苯衍生物的三阶非线性光开关性能的调控

偶氮苯衍生物因其具有特殊的共轭体系常用作光开关特性的三阶非线性光学（NLO）开关材料,但有部分带有特殊基团的偶氮类分子在一般条件下无法显示其性能.然而,这类分子在被调节之后能展示出优异的光控的NLO开关性能.以无光控的NLO开关性能的5-（N-4-偶氮苯基）氨甲基间苯二甲酸为研究对象,并对其潜在的光控NLO开关性能进行调控.经过调节后的这类分子在光照条件下能顺利地经历可逆的顺反异构化反应,且产生三阶非线性性能的转换.其Z-扫描实验结果显示处于反式构型的材料展示出反饱和吸收和自散焦特性;在光照之后,这类材料转化为顺式构型并展现出饱和吸收和自聚焦行为.三阶NLO性能的转换是由于材料的结构发生转变其内部电子产生重排,使得它们在激光刺激下产生不同的响应机制.     

含不同基团偶氮苯化合物的合成及其光致异构化性质

以苯胺或对硝基苯胺为起始原料,通过重氮偶合法合成了4种分别含有硝基、氨基和不同数目偶氮基的偶氮苯化合物(1~4),其结构经¹H NMR和FT-IR确证。研究了1~4在紫外灯(12 W)照射下随时间变化的UV-Vis谱图。结果表明：含有给电子基团(NH₂)偶氮苯的光致异构化速率较含有吸电子基团（NO₂）时更快,NO₂对分子的异构化有一定抑制作用;分子中偶氮基的数目增加时,顺反异构化过程也受到影响。     

以三亚吡嗪为中心的有机共轭分子的二阶NLO性质研究

采用密度泛函理论B3LYP/6-311G**方法,对一系列以三亚吡嗪为中心的有机共轭分子的二阶NLO性质和电子光谱进行了理论研究.结果表明,取代基推、拉电子能力的变化、相对数目及共轭桥的性质对研究分子的极化率及二阶NLO系数都有较大的影响.当研究分子以甲氨基为供体、以三氰基乙烯为受体、并以C=C双键为共轭桥时,显示了较大的二阶NLO活性和良好透光性的优化.该系列分子在NLO材料领域有较好的潜在应用价值.     

四氢吡咯双自由基及其等电子体系不同电子态稳定性和NLO性质的理论研究

摘要所选体系为非路易斯分子,即分子中含有一个可分裂的C—C键,两个电子占据非键分子轨道,对这类分子的能量和稳定性的研究已有报道．根据体系中两个自由基电子相互作用不同,该类分子可能具有三种电子态．本文采用密度泛函和从头算等方法在不同基组水平上,对四氢吡咯双自由基（体系a）及其两个等电子体系的NLO性质进行了理论研究．采用不同方法和基组优化体系a三种电子态的几何结构,     

含吡啶配体过渡金属(M=Cr(0),Mn(Ⅰ),Fe(Ⅱ),Co(Ⅲ))配合物二阶NLO性质的DFT研究

采用密度泛函理论（DFT）B3LYP／6-31G（d）方法对含吡啶配体的过渡金属（M=Cr（0）,Mn（Ⅰ）,Fe（Ⅱ）,Co（Ⅲ））配合物的几何构型进行优化,进一步结合有限场（FF）方法,计算其二阶NLO系数．结果表明,吡啶配体和中心金属原子之间的配位键键长随中心金属价态升高逐渐减小,增加吡啶配体的共轭链长度使极化率变得更大．共轭桥的增长有利于分子内电荷转移,对应体系的二阶NLO系数较大．     

碳硼烷桥连噻吩化合物结构和二阶非线性光学系数的DFT计算

采用密度泛函理论(DFT)B3LYP方法,计算分析了7个以碳硼烷和苯环为桥连基团化合物的非线性光学(NLO)特征,结果表明:桥连基团的体积越大,对提高极化率的值越有利;分子桥连部分的电子离域性以及分子的几何构型对二阶NLO系数有重要影响,电子跃迂时的电荷转移程度对二阶NLO性质有较大贡献.通过分析分子的电子光谱和对应的...     

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.     

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.     

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.