无皂乳液聚合制备含铕荧光共聚物乳液的研究及其表征

以丙烯酸(AA)为第一配体、邻菲罗啉(Phen)为第二配体、Eu3+为中心离子,合成了一种可聚合的稀土铕配合物.以配合物单体、甲基丙烯酸甲酯、丙烯酰胺和对苯乙烯磺酸钠为共聚单体,通过无皂乳液聚合的方法,制备了含铕荧光共聚物乳液.采用红外光谱对共聚物的结构进行了表征,并探讨了配合物单体含量对共聚物乳液性能的影响.透射电子显微镜(TEM)和激光光散射粒度仪(PCS)测试结果表明,共聚物乳液形成了相对均一的球状结构,但随着配合物单体含量增加,共聚物微球粒径逐渐增大、分散性变差.采用荧光分光光度计测试了共聚物乳液的荧光性能,在594和619 nm处出现Eu3+的特征发射光谱,且荧光强度随着配合物单体含量增加而增强.     

含铕荧光两亲接枝共聚物的制备及胶束化行为

以丙烯酸(AA)、 苯甲酸(BA)和邻菲啰啉(Phen)为配体, Eu³⁺为中心离子, 制备了可聚合荧光配合物单体, 并以此单体为功能单体, 聚乙二醇单甲醚甲基丙烯酸酯(MPEGMA)和甲基丙烯酸六氟丁酯(HFMA)为共聚单体, 通过溶液聚合制备出含铕两亲荧光接枝共聚物P-[HFMA-co-Eu(AA)(BA)₂Phen]g-PEG. 利用红外光谱(FTIR)和核磁共振波谱(¹H NMR和¹⁹F NMR)对共聚物的结构进行表征; 采用表面张力法测定共聚物的临界胶束浓度(cmc)为0.20 g/L; 通过透射电子显微镜(TEM)和动态光散射仪(DLS)观察胶束的形貌及其胶束化行为, 发现该共聚物可以形成大小均一的球形胶束, 且随着共聚物浓度的提高, 胶束粒径相应增大; 在溶液浓度达到临界胶束浓度时, 溶液荧光出现强度突变.     

含稀土铕双功能荧光磁性纳米粒子的制备及性能表征

首先制备了油酸和十一烯酸钠改性的水基磁流体,然后在其存在的情况下,将可聚合的稀土铕配合物单体Eu(AA)3Phen(AA=丙烯酸,phen=邻菲罗啉)与苯乙烯和甲基丙烯酸缩水甘油酯在过硫酸钾的引发下,进行无皂种子乳液聚合来制备荧光磁性高分子微球。 利用透射电子显微镜和动态光散射粒度仪表征了粒子的形貌及粒径,发现荧光磁性微球具有明显的核-壳结构及较窄的粒径分布;通过红外光谱和X射线衍射分析表征了粒子的化学及晶体结构;通过振动样品磁强计和荧光分光光度计表征粒子的磁性及荧光性能,发现荧光磁性微球具有超顺磁性,其荧光发射光谱在594和619 nm处出现Eu3+的特征荧光发射峰。     

基于大分子共组装法制备聚苯胺纳米粒子

首先,以丙烯酸(AA)、N-乙烯基吡咯烷酮(VP)和苯乙烯(St)为聚合单体,通过自由基共聚法合成了一种双亲无规共聚物P(AA-co-VP-co-St)。然后,在疏水作用和静电作用的共同诱导下,将该共聚物与聚苯胺(PANI)共组装形成形态可控且均匀分散的PANI纳米粒子。通过透射电子显微镜和激光动态光散射等研究了P(AA-co-VP-co-St)和PANI在水溶液中的共组装行为,并系统研究了亲水单体AA的物质的量分数对所制备的PANI纳米粒子粒径、形态的影响。结果表明:当AA物质的量分数为30%时,PANI纳米粒子的粒径最小。     

由氨解PDVB-alt-MAH纳米粒子作稳定剂的超声乳化-Pickering乳液聚合反应研究

采用以氨解的聚(二乙烯基苯-马来酸酐)交联共聚物纳米粒子(PDVB-alt-MAH nanoparticles,PDMNPs)为稳定剂、偶氮二异丁腈为引发剂、去离子水为分散介质、苯乙烯(St)为单体构成的体系,制备出聚苯乙烯(PSt)微球.利用扫描电子显微镜、激光粒度仪等仪器考察了PSt微球的形貌和粒径,分别探讨了单体乳液的稳定性、机械搅拌速率、稳定剂用量对聚合反应的影响,结果指出超声乳化和机械搅拌是必要的工艺条件,同时,发现在0.58 wt%~11.76 wt%(g/g St)的范围内增大稳定剂用量,PSt微球产物的尺寸由200 nm减小至90 nm;利用凝胶渗透色谱对聚合过程动力学进行了追踪分析;利用红外吸收光谱、X射线光电子能谱对PSt微球的化学结构进行了表征.研究结果表明,由氨解PDMNPs稳定的超声乳化-Pickering乳液聚合体系具有如下特点:(1)PDMNPs稳定效率高;(2)超声辅助的乳化设备简单;(3)所制备的球形PSt粒子表面无皂洁净、粒径分布较窄.该聚合方法用于甲基丙烯酸甲酯(MMA)、甲基丙烯酸缩水甘油酯(GMA)和α-甲基苯乙烯(AMS)等其他常见单体的聚合,结果表明,该方法对制备油溶性单体的聚合物微球具有普适性和通用性.     

微波辐照下无皂阳离子聚(St-MMA)高分子纳米粒子的制备和表征

讨论了微波辐照下 ,以丙酮 水为分散介质 ,利用阳离子型自由基引发剂偶氮二异丁基脒盐酸盐(AIBA)引发苯乙烯 (St)和甲基丙烯酸甲酯 (MMA)共聚 ,合成出表面带正电荷的P(St MMA)共聚物纳米粒子 ,考察了丙酮用量、单体和引发剂浓度对纳米粒子粒径、粒径分布和乳液稳定性的影响 .结果表明 ,丙酮 水的体积比由 0增加到 1 2 6∶1时 ,粒子的平均水化半径从 12 2 2 1nm降低到 2 4 6 8nm ,粒径分布变宽 ,乳液抗电解质稳定性逐渐增强 ;增加引发剂和共聚单体MMA的浓度 ,粒子的水化半径逐渐减小 ,粒径分散系数增大 .     

配体交换法制备水性含稀土磁性荧光微粒的研究及表征

利用共沉淀法合成Fe3O4磁性纳米粒子,并使用油酸改性生成了粒径均一的油性纳米粒子.使用3-(甲基丙烯酰氧)丙基三甲氧基硅烷,聚乙二醇甲基丙烯酸酯以及荧光可聚合配合物Eu(AA)3Phen为原材料合成了含有稀土金属Eu的两亲性的聚合物为配体,以油性Fe3O4为核,采用配体交换反应制备水性的磁性荧光微粒.并通过核磁共振波谱仪、傅里叶红外光谱仪、透射电子显微镜、动态光散射粒径测试仪、X射线衍射仪、振动样品磁强计、荧光分光光度计、热重分析仪对该微粒进行形貌、结构、超顺磁性以及荧光性能的测试表征.测试结果表明,两亲性聚合物良好有效地包覆在了磁性纳米粒子表面,制得的含稀土磁性荧光微粒在水相中具有良好的分散性,粒径均一,其平均粒径仅为45 nm,室温下的饱和磁化强度为2.3 A·m2/kg,研究过程中测得微粒中的稀土Eu3+在594 nm和619 nm有明显的特征发射光谱.     

微乳液聚合耦合共混法构建聚偏氟乙烯共混杂化膜

以苯乙烯和甲基丙烯酸甲酯混合物作为油相, 采用反相微乳液法制备了AgCl纳米粒子; 通过微乳液原位聚合油相单体得到包含AgCl纳米粒子的聚合乳液; 将聚合乳液与聚偏氟乙烯(PVDF)通过共混法构建了包含AgCl纳米粒子的PVDF共混杂化膜. 紫外-可见光谱、 透射电子显微镜(TEM)及扫描电子显微镜(SEM)等表征结果和超滤实验结果表明, 聚合乳液加入的同时引入了亲水性聚合物和表面亲水的AgCl纳米粒子, 不仅改善了PVDF共混杂化膜的孔隙率和平均孔径, 还显著增强了PVDF共混杂化膜的极性和亲水性, 最终提升了膜的水通量和抗污染性能; 过量聚合乳液加入后不能与PVDF材料均匀共混, 而且AgCl纳米粒子也会在膜中形成团聚物堵塞膜孔隙, 从而削弱了膜的水通量和抗污染性能.     

复配乳液体系中聚氯甲基苯乙烯纳米颗粒的制备

以初始质量分数为21.4%的氯甲基苯乙烯,在十二烷基苯磺酸钠(LAS)/聚醚复配乳液体系中制备了粒径为65.0nm,单分散性良好的聚氯甲基苯乙烯纳米微球.用红外光谱仪、透射电子显微镜、Zeta电位粒度仪测试技术对产物的化学结构、粒径大小、形貌、单分散性进行了表征.结果表明,在复配乳液体系中可以在提高单体含量的同时,保持产物的粒径在纳米级,同时体系的稳定性良好.透射电子显微照片显示,制得的纳米微球之间存在黏连.并提出了氯甲基的存在可能是产生这种现象的原因.     

SiO2@P（MMA/BA/3FMA）复合纳米粒子的制备及膜性能

通过溶胶-凝胶法与半连续种子乳液聚合法相结合,以正硅酸乙酯(TEOS)制备的纳米SiO2为核,以甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)和甲基丙烯酸三氟乙酯(3FMA)的共聚物P(MMA/BA/3FMA)为壳,合成了SiO2@P(MMA/BA/3FMA)核-壳结构纳米复合粒子.为防止纳米SiO2的团聚,提高其与共聚物的结合力,用乙烯基三甲氧基硅烷(VTMS)对纳米SiO2进行改性.通过红外光谱、透射电子显微镜、动态激光散射粒度仪、静态接触角测试仪、X射线光电子能谱分析和热重分析等表征了乳液结构及膜性能.结果表明,获得的复合纳米粒子呈现粒径分布为40～50 nm的核-壳结构球型颗粒.由于含氟官能团的迁移使得氟元素在膜-空气界面富集,有效降低了膜的表面自由能.当3FMA质量分数达到25%时,膜表面自由能达到最低值(23.13 mN/m).随着3FMA含量的增加,共聚物初始热分解温度由350℃提高到390℃.     

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%.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

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.