新型杯芳烃为载体的铅离子选择电极

报道了5,11,17,23-四（1,1-二甲基乙基）-25,27-二羟基-26,28-二[（2-丙酰胺）乙氧基]杯[4]芳烃1的合成及以此化合物为载体研制了PVC膜铅离子选择电极。研究了不同极性的膜增塑剂和亲脂性阴离子位点对铅离子选择电极响应性能的影响,测定了铅离子选择电极的性能。铅离子选择电极对铅离子表现出优良的能斯特响应和高选择性,能在pH4.0-6.5的范围内使用,该电极可作为电位滴定的指示电极。     

手性杯[4]芳烃氨基醇的合成及自组装

用25,27-二(2-溴乙氧基)-26,28-二羟基-5,11,17,23-四叔丁基杯[4]芳烃与光学纯的(1S,2R)-(+)-2-氨基-1,2-二苯基乙醇合成了手性杯[4]芳烃氨基醇2. 2能在极性的甲醇中组装成二聚体,通过¹H NMR滴定测定其结合常数K_a为34.7 M^-1,并提出了自组装机理.     

新型杯[4]芳烃氨基苯酚类衍生物的合成及对La3 的选择性识别

设计合成了下缘连有氨基苯氧基结构的杯[4]芳烃衍生物:5,11,17,23-四叔丁基-25-[2-(2-氨基苯氧基)乙氧基]-27-(2-羟基乙氧基)-26,28-二羟基杯[4]芳烃(化合物C),增加了与阳离子的结合位点,有利于通过配位作用对金属离子进行识别。化合物C的结构通过红外光谱、1H NMR、13C NMR和质谱进行了表征。通过紫外可见光谱和荧光发射光谱对化合物C与24种金属阳离子的络合作用进行了研究,结果发现,其对La3+有特殊的识别作用,化合物C与La3+的络合比为1∶1。     

杯芳烃衍生物液－液萃取和液膜传输银的对比研究及机理探讨

以4类含硫、硒、氮等杂原子基团二取代的杯[4]芳烃五衍生物（1－14）为中 性载体，在H2O-CHCl3-苦味酸体系萃取银和H2O-CHCl3-H2O液膜体系中传输银进行 了对比研究。萃取和传输结果具有一致性，除了苯并噻唑取代的杯[4]芳烃衍生物 （3－6）外，其它10个含硫、硒、氮的杯[4]芳烃衍生物1－14均对软重金属银和汞 有很高的选择性，而吡啶取代的杯[4]芳烃衍生物7－10对铅有一定的萃取选择性， 其中羟基硫醚取代的杯[4]芳烃衍生物11－14对银的萃取率和传输速率最大。并且 就杯[4]芳烃衍生物对银的传输机理进行了探讨，发现传输速率随源相中金属离子 浓度和有机相中载体浓度的增加而增大，因此推论这是由金属离子浓度梯度推动下 的传输。     

偶氮和亚氨基团作为下垂螯合臂的新型杯[4]芳烃衍生物的合成及性质

以对叔丁基杯[4]芳烃为原料,经过取代、缩合等多步反应,合成了5个下缘同时含有偶氮和亚氨基团的新型杯[4]芳烃衍生物,其结构经IR、1H NMR、13C NMR和元素分析进行了表征.并通过UV/Vis光谱研究了其对金属离子的识别作用.结果发现化合物25,27-二羟基-26,28-二{2-[2-(N-(4-苯偶氮基-1-萘基)亚氨基次甲基)苯氧基]乙氧基}对叔丁基杯[4]芳烃(4c)对Al3+和Sn2+有较好的识别作用,而化合物25,27-二羟基-26,28-二{2-[2-(N-(4-(4-甲基苯偶氮基)-1-萘基)亚氨基次甲基)苯氧基]乙氧基}对叔丁基杯[4]芳烃(4e)可以专一性地识别Al3+,其与Al3+络合的物质的量比为1∶1.     

Eu—Calix—2Ar修饰电极的制备及其电化学研究

杯芳烃由于具有多个紧密相邻的羟基和一个n体系空穴,使得杯芳烃几处乎能与所有的金属形成配合物^[1],这些金属配合物由于具有优良的催化、光电、分子识别性能而受到化学工作者关注^[2,3],然而对这些杯烃金属配合的电化学行为的研究却较少^[4],特别是针对稀土金属、过渡金属与杯芳烃及其衍生物所形成配合物的电化学行为的研究,国内至今尚未见报道,本文对铕（III）－5,11,17,23－四叔丁基－25,27－二苄氧基－26,28－二羟基杯[4]芳烃（Eu-Calix-2Ar）这一新的杯芳烃金属配合物膜修饰电极的制备,伏安性能及其氧化还原机理进行了研究,得到了一些有意义的结果。     

香豆素冠醚双功能化杯[4]芳烃的合成

以对叔丁基杯[4]芳烃为原料,经碱催化合成了26,28-双(4,7-双甲氧基香豆素)-5,11,17,23-四叔丁基杯[4]-冠-6(2)。其结构经1H NMR,IR和元素分析表征,2为锥形结构。     

25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃的合成

以对叔丁基杯[4]芳烃为原料脱除叔丁基得到杯[4]芳烃,再经醚化、缩合两步反应首次合成25,27-二(α,γ-二酮苯丁氧基)-26,28-二羟基杯[4]芳烃,其结构经1H NMR、13C NMR、MS及元素分析表征。研究表明,目标化合物中的α,γ-二酮结构存在酮醇异构现象,在溶液中其酮醇异构体比例近似为1∶2。     

二羟基二羟乙氧基杯[4]芳烃的合成与性质研究

通过杯[4]芳烃与碘乙醇的反应,制得了25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃,经IR,UV,1HNMR,13CNMR和MS等分析证实了产物的结构.用荧光光谱法研究了产物与稀土(Ⅲ)硝酸盐在乙腈溶液中的配位作用,并根据扩展的Hilderbrand-Benesi公式计算了配合物的稳定常数和配位反应的Gibbs自由能变化,结果发现,25,27-二羟基-26,28-二羟乙氧基杯[4]芳烃与稀土(Ⅲ)硝酸盐在乙腈溶液中具有较强的配位能力.     

新型杯[4]芳烃衍生物的合成及其氨基酸萃取性能

杯[4]-1,3-二乙酸乙酯衍生物(1)与水合肼反应生成杯[4]芳烃酰肼衍生物(2),化合物(2)与异硫氰酸苯酯反应得到含酰胺和硫脲单元的新型杯[4]芳烃衍生物(3).总产率达70%.系列氨基酸萃取实验表明化合物(3)对异亮氨酸有较好的选择性萃取能力.     

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.     

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.     

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.     

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.