含有二色性染料的PDLC的光电性能

用聚合分相法,在Ｅ－７液晶中掺入二色性液晶分散蓝,制成聚合物分散液晶膜。测定了它的光电性能。与不加二色性染料的聚合物分散液晶膜比较,膜对比度提高,响应时间τｏｎ保持不变,松驰时间τｏｆｆ略有增加。     

新型液晶／高聚物复合富氧膜的富氧性能及结构表征Ⅰ．液晶／高聚物复合膜的富氧性能研究

研究用烃橡胶和聚二甲基硅氧烷分散α、ω－对乙氧羰氧基苯甲酸聚乙二醇酯而得到聚合物分散液晶复合膜。用这种复合膜进行富氧分离，当ＰＥＥＣＢ－４．０５（４．０５为聚醚软段的数均聚合度ＤＰ）的含量超过某一临界值（约２３．０％ｗｔ）时，室温下ＳＢＲ／ＰＥＥＣＢ－４．０５／ＰＤＭＳ体系膜的氧气透过系数ＰＯ２值达７０－６３４ｂａｒｒｅｒ），增加约６０倍，分离系数仍较高。考察了各种影响因素对膜透气性能的影响。     

新型液晶／高聚物复合富氧膜的富氧性能及结构表征Ⅰ．液晶／高聚物复合膜的富氧性能研究

研究用烃橡胶（ＳＢＲ、ＰＢ）和聚二甲基硅氧烷（ＰＤＭＳ）分散α，ω－对乙氧羰氧基苯甲酸聚乙二醇酯（ＰＥＥＣＢ）而得到聚合物分散液晶复合膜（ＰＤＬＣＭ）．用这种复合膜进行富氧分离，当ＰＥＥＣＢ－４．０５（４．０５为聚醚软段的数均聚合度ＤＰ）的含量超过某一临界值（约２３．０％ｗｔ）时，室温下ＳＢＲ／ＰＥＥＣＢ－４．０５／ＰＤＭＳ体系膜的氧气透过系数Ｐｏ２值达７０～６３４ｂａｒｒｅｒ），增加约６０倍，分离系数仍较高（αｏ２／Ｎ２＝３．４７～２．５９）．考察了各种影响因素对膜透气性能的影响．     

紫外固化PDLC膜的形态及电光性能

选用紫外光固化法制备了聚合物分散液晶（ＰＤＬＣ）膜。以ＳＥＭ方法对其形态结构进行了考察，进而测试了ＰＤＬＣ的电光性能，并讨论了性能与结构的关系。     

苯乙烯在炭黑表面的阴离子接枝聚合研究

利用正丁基锂（ｎ－ＢｕＬｉ）与炭黑（ＣＢ）表面含氧基团反应制得了表面含－ＯＬｉ基团的反应型炭黑，以该炭黑与聚氧乙烯－聚氧丙烯－聚苯乙烯（ＰＥＯ－ＰＰＯ－ＰＳ）多嵌段聚合物组成的阴离子引发体系作活性中心，研究了苯乙烯在炭黑表面的阴离子接枝聚合。ＦＴ－ＩＲ，ＴＥＭ和ＤＳＣ分析表明在接枝炭黑表面存在苯乙烯的聚合物。接枝炭黑在甲苯中有良好的分散稳定性。     

新型液晶／高聚物复合膜的富氧性能及结构表征 Ⅱ．液晶／高聚物复合膜的结构表征

用ＩＲ、ＤＳＣ、ＷＡＸＤ、正交偏光显微镜、ＳＥＭ、ＴＥＭ等手段，表征了所合成的液晶／烃橡胶、硅橡胶三元共混复合膜的织态结构及液晶态转变，结果发现，液晶ＰＥＥＣＢ－４．０５由于与ＳＢＲ和ＰＤＭＳ共混，Ｔｋ－ｓ转变温度下降了３７．５℃，体系存在不完全的相分离，液晶ＰＥＥＣＢ－４．０５在体系中形成液晶富集区（ＬＣ－ｒｉｃｈ ｄｏｍａｉｎ），大小约０．２－２．２μｍ，在压力的作用下，连续的液晶富集区形成宽     

聚合物网络分散液晶复合膜的制备与性能研究

报道了一种新型树脂基的聚合物网络分散晶复合膜材料。研究了基体材料的组成，液晶种类，液晶含量，聚合温度，紫外光强度及聚合时间等聚合物网络分散液晶复合膜性能的影响。扫描电子显微镜观测，发现这种材料是由两个连相互穿构成了属于聚合物球型。     

新型液晶／高聚物复合膜的富氧性能及结构表征 Ⅱ．液晶／高聚物复合膜的结构表征

用ＩＲ、ＤＳＣ、ＷＡＸＤ、正交偏光显微镜、ＳＥＭ、ＴＥＭ等手段，表征了所合成的液晶／烃橡胶／硅橡胶三元共混复合膜的织态结构及液晶态转变．结果发现，液晶ＰＥＥＣＢ—４．０５由于与ＳＢＲ和ＰＤＭＳ共混，Ｔｋ－ｓ转变温度下降了３７．５℃，体系存在不完全的相分离．液晶ＰＥＥＣＢ—４．０５在体系中形成液晶富集区（ＬＣ—ｒｉｃｈｄｏｍａｉｎ），大小约０２—２．２μｍ不等．在压力的作用下，连续的液晶富集区形成宽约７．０μｍ并垂直于膜的平面的通道．这些结果是第Ⅰ报中这类富氧膜透气率产生突变的根本原因．     

聚合物分散液晶膜

聚合物分散液晶膜是将液晶和聚合物结合,得到的一种综合性能优异的膜材料,液晶分子赋予了聚合物分散液晶膜显著的电光特性,使其受到了广泛的研究,并有着广阔的应用前景。而聚合物作为成膜材料,起着辅助但是重要的作用,其结构和固化过程是影响聚合物分散液晶膜电光特性的重要因素。本文简要综述了聚合物分散液晶膜的制备方法、电光特性的影响因素及研究手段。     

含甲氧基悬挂基聚甲亚胺醚的合成及其液晶行为

以单体双－（３－甲氧基－４－羟基苄叉）－４，４＇－二亚胺基苯与ａ，ω－二溴烷，采用相转移催化聚醚化法合成７种主链型液晶聚甲亚胺醚，用＾１Ｈ ＮＭＲ、ＩＲ、ＵＶ、元素分析及热台偏光显微镜、ＤＳＣ和ＷＡＸＤ对聚合物的结构和液晶行为进行了表征。熔点和清亮点随间隔基数（ｎ）改变，并有奇偶效应，呈现锯齿形变化规律。     

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.     

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.     

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.