N-2-亚甲基-噻酚-二茂铁基芳胺衍生物的合成、晶体结构及电化学性质

以邻、间、对-二茂铁苯胺为原料, 合成了含噻酚的二茂铁苯基席夫碱衍生物并还原得到N-2-亚甲基-噻酚-二茂铁基芳胺衍生物，通过元素分析，IR，UV，¹H NMR和X-射线单晶衍射等分析手段，确证了标题化合物的组成和结构，单晶结构解析表明，化合物2c属于单斜晶系，P2/n空间群。量化计算结果证明，化合物2c在晶体中的结构并不是它的最稳定结构；其HOMO轨道主要由Fe原子及茂环上C的原子轨道组成的；电化学实验证明所得邻、间、对化合物的电化学性质相似，氧化还原峰对应于二茂铁的氧化还原过程，Fc⁺ + e^-←→Fc；说明化合物中的二茂铁基所处的化学环境相同，苯环上取代基位置的不同，对化合物在电极表面的扩散系数影响不大, 但对反应速率常数则有较大的影响。     

有机磷化合物的电子结构与成键

本文叙述了有机磷化合物的成键与性质,以及在理论上的新发展,分下面两个内容讨论:(1)磷原子的性质与成键。(2)各类有机磷化合物的电子结构与成键。     

含有柠檬酸配体的钼硫配合物的合成、光谱及电子结构

含有柠檬酸配体的钼硫配合物的合成、光谱及电子结构;钼硫化合物;柠檬酸;性质;电子结构     

两个新颖的稀土一有机框架化合物的合成、结构和磁性

两个新颖的金属．有机框架{[Eu（phen）（NDA）15（H20）]）n（（1）；NDA=2,6-naphthalenedicarboxylateions，phen=1，10．phenanthroline）和{[Gd（phen）（NDA）15]·0．5H2NDA}。（2）在水热条件下被合成出来．化合物1和2的结构分析表明，他们都属于三斜晶系，空间群为P-1．化合物1呈现出二维格子结构特点，而化合物2展现出新颖的三维结构．这两个框架化合物通过元素分析、发射光谱和变温磁化率的进一步表征．发光性质研究表明化合物1发出Eu^3＋离子特有的红光．磁性研究表明在化合物2中，相邻的Gd^3＋离子间存在铁磁耦合相互作用．     

新型黄烷酮类衍生物的合成、杀菌活性及定量构效关系研究

设计合成了14个含不同性质取代基的黄烷酮类化合物,并采用核磁共振氢波谱、质谱和元素分析对所有化合物的结构进行了表征.在系统测定化合物对水稻稻瘟病抑制活性的IC₅₀值的基础上,采用Hansch-Fujita方法和CoMFA方法对其定量结构活性关系进行了系统研究,结果发现,化合物的疏水性质、极化效应以及最高空轨道能级对杀菌活性有重要影响,化合物的疏水参数越小,分子越容易极化,则化合物的杀菌活性越高.此外,最高空轨道能级越低,化合物越容易接受电子,其杀菌活性也相应提高.通过考察∑π、clgP以及lgK与化合物杀菌活性的相关性,发现lgK能较好地反映该类化合物的疏水效应.三维定量构效关系研究表明,B环2,3,4位上含有较大体积的取代基,而6位含较小体积的取代基,有利于提高其杀菌活性.     

对初中化学第六章“硷、酸、盐”的体会

一、对第六章教材系统性的体会“氧化物、硷、酸、盐”一章教材的重要性:通过这章的教学,给学生树立无机物质分类的概念,认识各类化合物的通性和它们之间的联系,对高中进一步学习各类元素起着很大的作用。但是,这些知识如何教给学生则是值得研究的问题。所以这章教材编写系统如何,对教学起着很大的作用。新课本第六章教材在编写上的特点是每一类化合物都分两次提出。分两次提出,绝不是单纯的重复。原因有二:第一,因为提到某一类化合物必要牵涉到另一类化合物,如提到酸的性质,就要牵涉到硷和盐;提到酸性氧化物的性质,也必须要联系到酸和硷。所以不能一次便把某类化合物的知识全部讲完。第二,旧课本,难点比较集中,一次把酸类,硷类,盐类的知识教给学生,而学生又缺少在这方面知识的基础,因     

以结构为主线结合对比法进行杂环化合物教学

根据有机化合物结构决定性质的特点,提出了在杂环化合物教学中,以结构为主线对不同类杂环化合物的结构、性质和反应进行系统分类分析,并结合对比教学法帮助学生理解不同类杂环化合物反应性的教学方法.     

三苯基咪唑富勒烯吡咯烷衍生物的合成及其紫外、荧光和光限幅性质的研究

通过1,3-偶极环加成合成了四种三苯基咪唑富勒烯吡咯烷衍生物3a～3d,用FT-IR,NMR,MS和元素分析进行其结构测定和表征;用循环伏安法测定了其电化学性质,结果表明,与参比化合物C60相比还原电位发生负移,更容易形成电子受体;用纳秒和飞秒激光研究了四种化合物的光限幅性质,结果表明化合物3a和3c的纳秒光限幅性质明显,而3b则观察不到光限幅现象,说明化合物中硝基的引入不利于光限幅效应.     

一个晶态铅配位聚合物的合成、晶体结构、剥离及荧光性质

通过水热反应合成了1个二维层状结构的铅配位聚合物,[Pb(4-NPA)(H₂O)]_n(1)(4-H₂NPA=4-硝基邻苯二甲酸)。对化合物1进行了红外光谱、元素分析、热重性质以及单晶、粉末X射线衍射表征。在化合物1中,有机配体4-NPA₂-阴离子采用(κ¹-κ¹)(κ²-κ²)-μ₄桥连方式连接了4个Pb(Ⅱ)离子形成一维链状结构,该链状结构再通过1个羧酸基团形成一个二维无机层结构。利用"自上而下"的方法将该化合物在甲醇中进行了剥离实验。此外,我们还研究了化合物1的块状样品、剥离样品以及分散在甲醇中的样品的荧光性质。     

以主族元素为桥的梯形化合物的光电性质

梯形化合物具有大的平面π共轭结构, 不会产生构象扭曲, 可以有效增加π共轭长度, 因而表现出非常好的光电性质. 将主族元素引入到梯形化合物骨架中作为桥接单元不仅可以固定其结构而且由于主族元素和π共轭骨架之间的轨道相互作用, 可以实现对这类化合物光电性质的调节. 采用密度泛函理论对一系列主族元素桥的梯形化合物的结构和光电性质进行了理论研究, 从而可更好地理解和预测这类化合物的性质. 研究发现, 这类化合物的电子结构可以通过引入主族元素进行调节. 由于具有更大的π共轭程度, 四主族元素桥化合物的吸收与双主族元素桥化合物相比有明显的红移, 而且荧光寿命较短. 另外, 通过计算离子化势(IPs)、电子亲和能(EAs)和重组能(λ)考察了这类化合物的电子和空穴注入及传输性质. 研究发现, 四主族元素桥化合物表现出更强的电子和空穴注入能力.     

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.     

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.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.