7-(对甲酰基苯偶氮)-8-羟基喹啉-5-磺酸的合成及其双波长分光光度法测定镓

7－（对甲酰基苯偶氮）－8－羟基喹啉－5－磺酸是一新显色剂。该试剂在微碱性介质中（pH＝7．5）与镓形成黄色络合物。络合物λmax＝392nm，摩尔吸光系数ε392＝2．24×104L·mol-1·cm-1。同时在500nm呈现负峰，用双峰观波长法测定镓ε392～500＝6．89×104L·mol-1·cm－1，灵敏度是单波长法的三倍多．线性范围0～2．0×10－5mol／L。用拟定的方法测定了掺硅的GaAS材料及岩石中的镓，加入回收率为106％～110％；方法的相对标准偏差小于1．6％。     

2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯分光光度法测定微量锌

1引言本重氮氨基偶氮苯类试剂是分析性能优良的显色剂，2-羟基-3-羧基-5-磺酸基苯重氮氨基偶氮苯（HCSDAA）是其中新近合成的一种。我们已研究了其用于微量汞、铊、铜的分光光度测定和汞、铜的流动注射分析。本文发现，HCSDAA也是锌的高灵敏显色剂，据此提出的测定锌的方法灵敏、简便、选择性好，可不经预分离或使用掩蔽剂直接测定人发和锌强化营养盐中微量锌．2实验方法移取适量锌标准溶液于10mL比色管中，依次加入1％乳化剂OP＄液1。mL，0．04％HCSDAA乙醇溶液亚．8mL、0．05mol／L硼砂一Na0H缓冲溶液（pH11．0）2．5mL，用水…     

用2-(对磺基苯偶氮)变色酸胶束增溶光度法测定微量镁

在混合表面活性剂（CPB＋OP）存在下，镁（Ⅱ）和2－（对磺基苯偶氮）变色酸（SPADNS）的络合反应发生显著的增敏作用，其λmax为606nm，比无混合表面活性剂时红移33nm，灵敏度提高近11倍，表观摩尔吸光系数（ε'）达1．23×105·mol-1·cm－1.测量的pH范围为10．0～11．3，镁浓度在0～200μg／L内符合比尔定律．Fe3＋、Al3＋等干扰离子可用TEA－甘露醇联合掩蔽。用拟定的方法测定了铝合金中的镁，结果满意．     

2-羟基-4-磺酰氨基苯重氮氨基偶氮苯的合成及环境污水中微量汞的测定

研究了 2 羟基 4 磺酰氨基苯重氮氨基偶氮苯 (HSDAA)与汞的显色反应。在TritonX -1 0 0表面活性剂存在下 ,pH 9 5～ 1 1 5的Na2 B4 O7-NaOH缓冲溶液中 ,该试剂与汞 (Ⅱ )生成配合比为 3∶1的深红色配合物。配合物的最大吸收峰位于λ=5 2 0nm处 ,表观摩尔吸光系数 1 47× 1 0 5L·mol- 1·cm- 1。Hg2 + 的质量浓度在 0～ 480 μg/L范围内符合比耳定律。用拟定方法测定环境污水中的微量汞 ,结果满意。     

二安替比林-(2-甲氧基)-苯基甲烷光度法测定铬

合成了新试剂二安替比林－（2－甲氧基）－苯基甲烷（DAoMM）；研究了在Mn（Ⅱ）存在下，DAoMM与Cr（Ⅵ）生成橙黄色化合物。该化合物最大吸收位于480nm；表观摩尔吸收系数为ε=1．58×105L·mol－1·cm－1和ε2=9．85×104L·mol－1·cm－1化合物至少稳定20h。服从比尔定律范围0～1．6×102μg／LCr（Ⅵ）和2×102～8×102μg／LCr（Ⅵ）。用于含铬废水和电镀废液中铬的测定，结果满意。     

苯并-18-冠醚-6和溴百里香酚蓝离子对萃取光度法测定钾

报道了以苯并 18 冠醚 6 K+ 与溴百里香酚蓝显色体系光度法测定钾的研究。一定条件下 ,苯并 18 冠醚 6与钾离子形成络合阳离子 ,与阴离子溴百里香酚蓝形成离子对缔合物 ,被萃入氯仿中。该离子对缔合物于 4 10nm处有最大吸收 ,测定钾的摩尔吸光系数为 1.6× 10 4 L·mol- 1·cm- 1,钾含量在 0 .0 5～ 2 .5 μg·ml- 1范围内呈线性关系 ,相对标准偏差为 2 .2 %。应用于土壤、植物和血清中痕量钾的测定 ,与原子吸收光谱法相比 ,结果满意     

对氯苯重氮氨基偶氮苯分光光度法测定微量汞

研究了对氯苯重氮氨基苯偶氮苯 (p -CBDAA)与Hg (Ⅱ )的显色反应 ,在非离子表面活性剂OP存在下 ,在pH 9 5的硼砂缓冲介质中 ,Hg (Ⅱ )与P -CBDAA形成 1∶2的橙红色稳定络合物 ,其λmax=5 3 0nm ,ε=1 2 0× 1 0 5L·mol- 1·cm- 1,汞含量在 0～ 0 8μg/mL范围内遵守比尔定律。方法用于废旧钮扣电池和自来水中汞的测定 ,结果令人满意。     

用铜(Ⅱ)-过氧化氢-二苯碳酰二肼/氯仿体系催化-萃取光度法测定铜

本文研究了在弱酸性介质中，利用铜（Ⅱ）催化过氧化氢氧化二苯碳酸二肼生成二苯卡巴腙的指示反应与铜（Ⅱ）和二苯卡巴腙的显色反应相结合，建立了催化-萃取光度法测定铜的新方法。方法的线性范围为5．0～500μg／L，表观摩尔吸光系数为8．8×104L·mol－1·cm-1。用于水、铝合金和岩石中铜的测定。结果满意。     

藉聚2-丙烯胺缩-3-(4-甲酰基苯偶氮)-4,5-二羟基-2,7-萘二磺酸分光光度法测定生物体液、食品和饮品中的镁

聚2-丙烯胺缩3－（4-甲酰基苯偶氮）-4，5-二羟基-2，7-萘二磺酸（PA-FPNS）在pH11．5的磷酸盐介质中．与镁（Ⅱ）形成一蓝色络合物，其最大吸收位于604nm，表观摩尔吸光系数ε=5．7×104L·mol-1·cm-1，线性范围为0．01～0．35mg／L，至少稳定12h。考察了30多种共存离子的影响，在所测样品中它们不干扰，无需掩蔽或分离即可直接测得其中的镁。     

2-羟基-3-羧基-5-磺酸基苯基重氮氨基偶氮苯吸光光度法测定微量钯

于pH9.3～10.6Na_2CO_3-NaHCO_3缓冲介质中,在Triton N-101存在下,Pd(Ⅱ)与2-羟基-3-羧基-5-磺酸基苯基重氮氨基偶氮苯(HCSDAA)形成组成比为1:2的红色配合物,其最大吸收波长为530nm,表观摩尔吸光系数为1.05×10~5,线性范围为0～0.7μg·ml~(-1) .结合丁二酮肟螯合,氯仿萃取,方法用于贵金属二次合金中微量钯的测定,相对标准偏差为2.0%(n=6).加标回收率为93.8%～99.3%.     

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.