Mo（Ⅵ）－PAN与Mo（Ⅵ）－PAR体系的极谱性质对比研究

本文比较了Ｍｏ（Ⅵ）－１－（２－吡啶基偶氮）－２－萘酚（ＰＡＮ）与Ｍｏ（Ⅵ）－４（２－吡啶基偶氮）间苯二酚（ＰＡＲ）的极谱性质，讨论它们在作为吸附波试剂时的优缺点，以求得在选择络合剂时的感性和理性认识．本文还报道了Ｍｏ（Ⅵ）－ＰＡＮ－ＫＢｒＯ３吸附催化波体系，最佳实验条件，０．１ｍｏｌ／ＬＨＡｃ－－ＮａＡｃ，ｐＨ＝４．６，０．０１ｍｏｌ／ＬＫＢｒＯ３，２．５×１０－５ｍｏｌ／ＬＰＡＮ．峰电位为－０．７１Ｖ（ｖｓ．ＳＣＥ），检出限１×１０－９ｍｏｌ／Ｌ，线性范围０～６×１０－７ｍｏｌ／Ｌ     

铁(Ⅲ)-PAN亚硝酸钠吸附催化波

本文在铁－ＰＡＮ络合吸附波体系中引入亚硝酸钠,使测铁的灵敏度提高约２０倍,是目前测铁灵敏度很高的极谱方法。峰电位为－０．５９Ｖ（ｖｓ．ＳＣＥ）,检出限约为１×１０－９ｍｏｌ／Ｌ。最佳测定条件为：ｐＨ３．０,ＰＡＮ１．５×１０－５ｍｏｌ／Ｌ,ＮＯ－２８×１０－２ｍｏｌ／Ｌ     

锗(Ⅳ)-邻苯二酚紫-钒(Ⅳ)体系的极谱吸附催化波研究

在０．１ｍｏｌ／ＬＨ２ＳＯ４溶液中，Ｇｅ（Ⅳ）－邻苯二酚紫（ＰＶ）－Ｖ（Ⅳ）体系产生一灵敏的吸附催化波，峰电位在－０．５５Ｖ（ｖｓ．ＳＣＥ）处．锗浓度在２．２×１０－１０～２．８×１０－６ｍｏｌ／Ｌ范围内与峰电流呈线性关系．检出限为１．１×１０－１０ｍｏｌ／Ｌ．研究了极谱波的性质．本法用于土壤中痕量锗的测定，结果满意．     

吡哆醛的电化学行为研究

用单扫示波极谱法，吡哆醛在０．２ｍｏｌ／ＬＫＣｌ＋０．０２ｍｏｌ／Ｌ ｎａＯＨ底液中，产生一良好的寺阶导数峰，ＥＰ＝－１．３０±０．０１Ｖ（ＳＣＥ），其峰高与浓度在２×１０＾－７－２×１０＾－４ｍｏｌ／Ｌ范围内成线性关系，检出限为１×１０＾－７ｍｏｌ／Ｌ实验证明，其电极过程为伴有微弱吸附性质的的可逆扩散过程（ｎ＝２），不在弱酸性和中性介质中时，吡哆醛的电极过程为前行动力学过程，其电极反应机理为伴有     

铜（Ⅱ）锌（Ⅱ）—氟哌酸体系电化学行为及示波极谱法研究

铜（Ⅱ）和锌（Ⅱ）分别在０．１ｍｏｌ／ＬＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４缓冲溶液（ｐＨ６．５）和０．２５ｍｏｌ／ＬＮＨ４Ｃｌ溶液中，与氟哌酸形成良好的络合吸附波，峰电位分别为－０．２６Ｖ和－１．２８Ｖ（ｖｓ．ＳＣＥ），络合比分别为１：３和１：２，峰电流与铜（Ⅱ）和锌（Ⅱ）的浓度均在４．０×１０＾－７～５．０×１０＾－６ｎｏｌ／Ｌ范围内呈线性关系，检测限分别为７．０×１０＾－８和５．０×１０＾－８ｍｏｌ     

含TBP的PS－EC复合膜微胶囊的制备及对Cr_2O_7~（2－）传输的研究

将聚苯乙烯（ＰＳ）和乙基纤维素（ＥＣ）溶于ＣＨ_２Ｃｌ_２中，利用水中干燥法制备ＰＳ－ＥＣ复合膜微胶囊。当复合膜的微孔中含有磷酸三丁酯（ＴＢＰ）时，微胶囊膜对Ｃｒ_２Ｏ_７~（２－）具有传输功能。芯材采用高浓度ＮａＯＨ时，可使Ｃｒ_２Ｏ_７~（２－）逆浓差传输。研究了ＰＳ和ＥＣ的比例、微胶囊粒径、ＮａＯＨ浓度及ＴＢＰ含量对传输的影响．在适当条件下，１０ｍｉｎ内Ｃｒ_２Ｏ_７~（２－）的浓度由１×１０~（－４）ｍｏｌ／Ｌ降至１×１０~（－７）ｍｏｌ／Ｌ以下。     

氧氟沙星的单扫描示波极谱分析

报道了一种灵敏的氧氟沙星测定方法－一阶导数单扫示波极谱分析，同时研究了它的极谱波性质和电极反应机理，在ｐＨ６．０的ＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４（ＰＢＳ）底液中，氧氟沙星产生一个灵敏的还原峰，Ｅｐ＝－１．５５Ｖ（ｖｓ．ＳＣＥ），其导数峰高与浓度在１．０×１０＾－５～４．６×１０＾－７ｍｏｌ／Ｌ范围内呈良好的线性关系，相关系数ｒ＝０．９９９６，检测下限为２．４×１０＾－７ｍｏｌ／Ｌ，可用于氧氟沙星片剂     

巯基钴卟啉自组装膜的表征及催化性能

用自制的新型尾式巯基钴（Ⅱ）卟啉在金电极上制成自组装单分子膜,并用ＸＰＳ,ＳＥＭ和电化学的方法进行了表征。该膜对抗坏血酸具有良好的催化作用,其氧化过电位较裸金电极上降低了１４０ ｍＶ,响应电流与抗坏血酸（ＡＡ）的浓度在 ７．８ × １０－５ｍｏｌ／Ｌ～１．０×１０－２ｍｏｌ／Ｌ的范围内具有良好的线性关系,相关系数为 ０．９９８１;检测下限为 １．３ × １０－８ｍｏｌ／Ｌ（富集 １０ｍｉｎ）。     

聚N,N-双水杨醛乙二胺合钴修饰超微电极的制备及其在一氧化氮测定中应用的研究

通过电化学聚合法制备了聚Ｎ，Ｎ－双水杨醛乙二胺合钴［ｐｏｌｙＣｏ（Ｓａｌｅｎ）］修饰超微电极，研究了该修饰电极的电催化性质及其在一氧化氮（ＮＯ）测定中的应用．实验结果表明，ｐｏｌｙＣｏ（Ｓａｌｅｎ）修饰超微电极对ＮＯ的测定有高的灵敏度，ＮＯ的浓度在２．０×１０－８～２．８×１０－６ｍｏｌ／Ｌ范围内，电流与浓度呈良好的线性关系，线性相关系数为０．９９９８，检出限为１．０×１０－８ｍｏｌ／Ｌ；该电极进一步修饰Ｎａｆｉｏｎ后，生物体中常见的物质如抗坏血酸、儿茶酚胺类神经递质的代谢物、ＮＯ的氧化产物ＮＯ－２等不干扰测定．本传感器可以满足ＮＯ在体分析的需要．     

淋必治的极谱研究

在０．１ｍｏｌ／Ｌ ＨＡｃ－ＮａＡｃ（ｐＨ４．５０）支持电解质中，淋必治（ＳＰＥ）有一灵敏的示波极谱导数还原峰，峰电位Ｅｐ＝－０．９８Ｖ（ｖｓ．ＳＣＥ）。峰电流与ＳＰＥ的浓度在２．０×１０＾－７￣８．０×１０＾－５ｍｏｌ／Ｌ范围内呈线性关系，最低检出限为５．０×１０＾－８ｍｏｌ／Ｌ。该法用于注射针剂中ＳＰＥ含量的测定。，结果良好。文中对ＳＰＥ的极谱行为、电极过程及反应机理进行了探讨。     

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.     

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.     

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.     

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.     

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.