CH（B~2Σ~－）和卤代甲烷、CS_2、O_2及Ar碰撞过程动力学研究

用四倍频ＹＡＧ激光（２６６ｎｍ）光解ＣＨＢｒ_３产生ＣＨ（Ｂ~２Σ~－）自由基，通过测量自发辐射ＣＨ（Ｂ→Ｘ）的时间分辨信号测得室温下ＣＨ（Ｂ）被卤代甲烷、ＣＳ_２、Ｏ_２及Ａｒ的猝灭速率常数（×１０~（－１０）ｃｍ~３·ｍｏｌｅｃ~（－１）·ｓ~（－１））分别为４．４±０．７（ＣＨ_２Ｃｌ_２）、５．２±０．４（ＣＨＣｌ_３）、５．０±０．７（ＣＣｌ_４）、８．２±０．３（ＣＨＢｒ_３）、７．９±０．７（ＣＳ_２）、０．１９±０．０２（Ｏ_２）及（１．１±０．１）×１０~（－２）（Ａｒ）．结果表明，除Ｏ_２外，其它猝灭剂对ＣＨ（Ｂ）的猝灭速率常数均大于对ＣＨ（Ａ）的。对卤代甲烷分子，猝灭速率常数显示了因Ｃｌ原子数增加而增加的趋势。     

二溴羟基苯基荧光酮荧光猝灭法测定Br~－

本文报道了以二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）为指示剂，在阳离子表面活性剂ＣＰＣ存在下荧光猝灭间接测定Ｂｒ￣－的新方法。在０．６ｍｏｌ／ＬＨ＿２ＳＯ＿４介质中，Ｂｒ￣－和ＢｒＯ反应生成Ｂｒ＿２，Ｂｒ＿２与ＤＢＨ－ＰＦ（λ＿（ｅｘ）＝４９５ｎｍ，λ＿（ｅｍ）＝５２０ｎｍ）生成红色化合物，使体系荧光猝灭。Ｂｒ￣－含量在０．２５～６．２５μｇ／２５ｍＬ范围内有良好的线性关系，检测限为０．２５μｇ／２５ｍＬ。该法灵敏度高，选择性好，用于合成海水样品中Ｂｒ￣－的测定，结果满意。     

二溴羟基苯基荧光酮荧光猝灭法测定Br^—

本文报道了以二溴羟基苯基荧光酮（ＤＢＨ－ＰＦ）为指示剂，在阳离子表活性剂ＣＰＣ存在下荧光猝灭间接测定Ｂｒ＾－的新方法。在０．６ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｂｒ＾－和ＢｒＯ３＾－反应生成Ｂｒ２，Ｂｒ２与ＤＢＨ－ＰＦ（λｅｍ＝５２０ｎｍ）生成红色化合物，使体荧光猝灭。Ｂｒ＾－含量在０．２５－６．２５μｇ／２５ｍＬ范围内有良好的线性关系，检测限为０．２５μｇ／２５ｍＬ。该法灵敏度高，选择性好，用于合成海     

荧光分析法测定痕量丁二酮

本文报道了邻苯二胺与丁二酮在１ｍｏｌ／ＬＨ２ＳＯ４介质中反应生成２，３－二甲基喹喔啉。该化合物具有较强的荧光（λｘ／λｅｍ＝３４０ｎｍ／４９０ｎｍ）其荧光量子产率ΦＦ＝０．１０１。丁二酮浓度在４．０×１０＾－７～５．２×１０＾－５ｍｏｌ／Ｌ范围内与转化成产物的相对荧光强度呈线性关系，相对标准偏差为１％，检出限为１．３×１０＾－７ｍｏｌ／Ｌ，考察了３０种物质表明，该法选择性好，用于实际啤酒样品中丁二     

4—甲基伞形酮荧光猝灭法测定苦味酸

本利用苦味酸对４－甲基伞形酮荧光的猝灭的猝灭效应，提出了一种新的测定苦味酸的方法，线性范围为１×１０＾－４－１×１０＾－８ｍｏｌ／Ｌ，以３σ衡量，检出限为８×１０＾－７ｍｏｌ／Ｌ，用于药品奎宁的间接测定和水样中苦味酸的直接测定，结果令人满意。     

铁（Ⅲ）—过氧化氢—水杨基荧光酮—溴化十六烷基三甲铵荧光猝灭反应？…

在ｐＨ３．１～５．２的ＨＣｌ－ＮａＡｃ缓冲介质中,溶液中的铁（Ⅲ）与过氧化氢（Ｈ２Ｏ２）,水杨基荧光酮（ＳＡＦ）和溴化十六烷基三发（ＣＴＭＡＢ）反应产生一多元混合络合物,使水杨基荧光酮溶液的荧光明显猝灭,据此建立了测定痕量铁的荧光猝灭分析法,该体系的激发波长λｅｘ＝４３５．８ｎｍ,发射波长λｅｍ＝５４０ｎｍ。铁的浓度在２～１００ｕｇ／Ｌ范围内有良好的线性关系;方法的检出限为０．４１ｕｇ／Ｌ。该方法     

Triton X-100与牛血清白蛋白的相互作用

应用荧光光谱法研究了溶液体系中Ｔｒｉｔｏｎ Ｘ－１００（ＴＸ）与牛血清白蛋白（ＢＳＡ）之间的相互作用。实验表明ＴＸ对ＢＳＡ的荧光有较强的猝灭作用,二者形成不发荧光的复合物所产生的静态猝灭是引起荧光猝灭的主要原因。从荧光猝灭结果求得二者的结合常数,发现在不同ＴＸ浓度下,结合常数Ｋ及络合个数ｎ均不同;低于ＴＸ的ｃｍｃ,Ｋ＝４４０ｍｏｌ／Ｌ,ｎ＝０．９１,高于ｃｍｃ,Ｋ＝１０ｍｏｌ／Ｌ,ｎ＝０．４２,疏     

吖啶橙与牛血清白蛋白的相互结合反应

应用光谱法研究了水溶液体系中吖啶橙与牛血清白蛋白分子间的相互结合反应，其结合常数为ｋ＝４．８×１０＾３ｍｏｌ／Ｌ，结合位点数为ｎ＝０．２８。并依据Ｆｏｒｓｔｅｒ非辐射能量转移机制，探讨了吖啶橙与牛血清白蛋白相互结合时，其给体－受体间距离（Ｒ０＝１．５ｎｍ）和能量转移效率（Ｅ＝０．３２）。证实了吖啶橙与牛血清白蛋白的相互结合作用为单一的静态猝灭过程，且阐明了其猝灭机制是通过能量转移产生的。     

钙黄绿素蓝荧光猝灭测定茶叶中的锰

本文研究了Ｍｎ（Ⅱ）－钙黄绿素蓝的荧光体系的测定方法及条件，在ＰＨ９．５－１０．０的硼砂－氢氧化钾缓冲溶液中，钙黄绿素蓝的λｅｘ为３６２ｎｍ，λｅｍ为４４６ｎｍ，Ｍｎ（Ⅱ）与钙黄绿素蓝生成的１：１络合物猝灭钙黄绿素蓝的荧光。锰量的线性范围为０．０５－１．０μｇ／１０ｍＬ，方法灵敏度高，检测限为５ｎｇ／ｍＬ。该方法用于茶叶中锰的测定，结果满意。     

冠醚存在下稀土络合物荧光体系的荧光增强效应

本详细研究了冠醚对Ｅｕ－ＴＴＡ荧光体系的增敏作用和稀土离子Ｄｙ＾３＾＋或Ｈｏ＾３＾＋对Ｅｕ－ＴＴＡ－冠醚体系的荧光强增效应。对Ｅｕ－ＴＴＡ－冠醚和Ｅｕ－Ｄｙ（或Ｈｏ）－ＴＴＡ－冠醚体系，Ｅｕ的浓度分别在１．０×１０＾－＾８－４．０×１０＾－＾６ｍｏｌ／Ｌ，１．０×１０＾－＾９－１．０×１０＾－＾７ｍｏｌ／Ｌ和１．０×１０＾－＾８－９．０×１０＾－＾６ｍｏｌ／Ｌ范围内与体系的荧光强度呈线性关系，检     

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.