荧光素荧光猝灭法测定微量碘酸根

报道了荧光素为指示剂荧光猝灭法间接测定ＩＯ３－的方法。在０．０５ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｉ－和ＩＯ３－反应生成Ｉ２，I２与荧光素反应、使荧光素荧光猝灭。该体系的激发波长和发射波长分别为４９３ ｎｍ和５１４ ｎｍ。ＩＯ３含量在２～８０ μｇ／Ｌ范围内有良好的线性关系，测定下限为 ２ μｇ／Ｌ。该法灵敏度高，选择性好，操作简单。用于含碘食盐、低钠食盐中微量ＩＯ３的测定，结果满意。     

荧光素荣光猝灭法测定向量磺酸根

报道了荧光素为指示剂荧光猝灭法间接测定ＩＯ＾－３的方法。在０．０５ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｉ＾－和ＩＯ＾－３反应生成Ｉ２，Ｉ２与荧光素反应，使荧光素荧光猝灭。该法灵敏度高，选择性好，操作简单，用于含碘食盐，低钠食盐中微量ＩＯ＾－３的测定，结果满意。     

二氯荧光素—氯化十六烷基吡啶荧光猝灭法测定微量碘

本文研究了用二氯荧光素（ＤＣＦ）－氯化十六烷基吡啶（ＣＰＣ）体系荧光猝灭法测定微量碘。在ｐＨ为２．８－３．１的Ｈ２ＳＯ４介质中，检出限为０．３０μｇ／２５ｍｌ线性范围为０．３０－２．００μｇ／２５ｍｌ，本法灵敏度高，选择性好，适用于微量碘的测定。     

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     

中性红作试剂荧光光度法测定亚硝酸根

研究了在盐酸介质中ＮＯ＾－２与中性红的亚硝化反应。结果表明，在０．０４８ｍｏｌ／Ｌ的盐酸介质中，ＮＯ＾－２与中性红反应生成无荧光的物质，ＮＯ＾－２在４０－２４０μｇ／Ｌ，范围内与荧光猝灭程度成正比，常见的共存离子不干扰其测定。所拟方法用于水样中ＮＯ＾－２的测定，结果满意。     

2‘,7’—二氯荧光素荧光法测定环境水样中的酚

报道了以２＇，７＇－二氯荧光素（ＤＣＦ）为指示剂，荧光法间接测定痕量酚的新方法。在０．５ｍｏｌ／Ｌ Ｈ２ＳＯ４介质中，Ｂｒ＾－和ＢｒＯ３＾－反应生成Ｂｒ２，Ｂｒ２与２＇，７＇－二氯荧光素反应，使２＇７＇－二氯荧光素荧光猝灭，当加入酚时，酚的溴代反应使体系荧光增强。ｐＨ４．０￣６．０范围内，该体系激发波长，发射波长分别为λｅｘ５０５ｎｍ，λｅｍ５２０ｎｍ。酚浓度在１．６￣５２ｎｇ／Ｌ范围内呈线性关系     

碘化物—罗丹明B体系荧光猝灭反应测定痕量亚硝酸根

拟定了一个荧光猝灭法测量痕量亚硝酸根的新方法。在盐酸介质中，亚硝酸根氧化碘化钾的反应，其反应物Ｉ＾－３使罗丹明Ｂ荧光猝灭，方法的检出限为３．６μｇ／Ｌ；测定范围为１０－１２０μｇ／Ｌ。方法简便快速，选择性好，用于自来水，矿泉水及合成样品中亚硝酸根的测定，结果满意。     

KBrO3—KBr紫外分光光度法测定痕量水杨酸

研究了ＨＣｌ溶液中ＫＢｒＯ３－ＫＢｒ紫外分光光度法测定水杨酸的条件,建立了测定痕量水杨酸的新方法。结果表明,在０．６ｍｏｌ／ＬＨＣｌ,３＊１０＾－５ｍｏｌ／ＬＫＢｒＯ３,５＊１０＾－４ｍｏｌ／ＬＫＢｒ,６＊１０＾－４ｍｏｌ／ｌＫＩ溶中测定水杨酸,其线性范围为０．２－４．０ｍｇ／Ｌ,表观摩尔吸光系数为１．９＊１０＾－４Ｌ．ｍｏｌ＾－１．ｃｍ＾－１,Ｓａｎｄｅｌｌ为７．３μｇ／ｃｍ＾２。ｓｇ ｉｆ ｅ     

异硫氰酸荧光素荧光猝灭法测定痕量碘酸根

碘酸根与碘离子反应生成游离碘使异硫氰酸荧光素的荧光猝灭,λｅｘ为４８７ｎｍ,λｅｍ为５１７ｎｍ,碘酸根含量在２－８μｇ／Ｌ范围内与荧光猝灭程度有良好线性关系,检测限为０．７４μｇ／Ｌ,该法灵敏度高,操作简便,用于含碘含盐中微量碘酸根的测定,结果满意。     

痕量草酸的催化荧光分析

在０．０４ｍｏｌ／Ｌ Ｈ２ＳＯ４介质中及８０℃条件下,草酸对Ｋ２Ｃｒ２Ｏ７氧化罗丹明Ｂ这一荧光猝灭反应具有较强的催化作用。以自来水冷却中止反应,采用荧光法研究了催化测定草酸的各种影响因素,建立了一个测定范围和检出限分别为０．０３－３μｇ／ｍＬ和０．０１μｇ／ｍＬ草酸的催化荧光分析法,用于尿样分析,结果满意。     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.