用氯离子选择电极同时分析水中Cl^—,Br^—,I^—的含量

本文研究了氯离子选择电极同时测定水中Ｃｌ＾－，Ｂｒ＾－，Ｉ＾－的方法。利用氯电极对Ｂｒ＾－，Ｉ＾－的响应，用混合加入法测定，非线性最小二乘法计算求解。测定了实际体系中Ｂｒ＾－，Ｉ＾－，在氯电极上的选择系娄，然后用多次标准加入法测定，迭代法同时计算各组份的分析结果，众而实现了用氯电极同时分析水中Ｃｌ＾－，Ｂｒ＾－，Ｉ＾－的含量。     

ICP－AES间接法连续测定混合物中的氯和碘离子的研究

本文研究了在Ｃｌ￣－和Ｉ￣－的混合物中，加入过量Ａｇ￣＋使Ｃｌ￣－和Ｉ￣－分别以ＡｇＣｌ和ＡｇＩ沉淀后，用ＩＣＰ－ＡＥＳ测定剩余的Ａｇ￣＋，然后用ＮＨ＿３·Ｈ＿２Ｏ溶解ＡｇＣｌ沉淀，测定溶解液中的Ａｇ￣＋，间接得到Ｃｌ￣－的含量，以差减法求得Ｉ￣－量，实现Ｃｌ￣－和Ｉ￣－的间接法连续测定。本文探讨了有关的化学条件和光谱测定条件，对方法的适用性进行了考察──共存离子的干扰情况，方法的精密度、检出限和试样中加入回收试验。回收率为９７．１％～１０１．２％（Ｃｌ￣－），９８．１％～１００．４％（Ｉ￣－）。     

抑制型离子色谱快速测定I~－、SCN~－、S_2O_3~（2－）

本文用抑制型离子色谱，薄壳强碱性阴离子交换树脂为分离柱，柱温为３０±１℃，在常规淋洗液ＮａＨＣＯ＿３－Ｎａ＿２ＣＯ＿３中加入对－硝基苯酚作为有机改进剂，测定了Ｉ￣－、ＳＣＮ￣－、离子。它们有良好的线性关系，三种离子的浓度在５．０～３０．０ｍｇ／Ｌ范围内其相关系数分别为：０．９９９４、ｒ＿（ＳＣＮ）￣（－０．９９０６），检测限分别为：Ｉ￣－０．１７ｍｇ／Ｌ、ＳＣＮ￣－０．１０ｍｇ／Ｌ、Ｌ。     

尿素－NaBr－KBr熔体中钴及稀土－钴的电沉积

稀土－钴合金具有许多优异性能,可用于制作磁性、磁光…等功能材料。日本学者研究了在有机电解液中电沉积Ｃｏ－Ｇｄ薄膜,未见前人研究低温熔盐体系中电沉积稀土合金的报道。尿素－（７９ｍｏｌ％）－ＮａＢｒ（１９．５ｍｏｌ％）－ＫＢｒ（１．５ｍｏｌ％）的熔点为５１℃,可在１００℃左右下作为电解介质。在尿素熔体中加入ＢａＯＡｃ,能增加Ｃｏ￣（２＋）还原为Ｃｏ的阴极极化。因此选择１００℃的尿素－ＮａＢｒ－ＫＢｒ－ＮａＯＡｃ作为本底熔体,研究Ｃｏ￣（２＋）的电还原,镧、铽、镝、铥各自与钴的电解共沉积。在所研究的熔体中,Ｃｏ￣（２＋）一步不可逆还原为Ｃｏ。测定Ｃｏ￣（２＋）＋２ｅ＝Ｃｏ反应的传递系数α为０．４５,Ｃｏ￣（２＋）在熔体中的扩散系数为２．５×１０￣（－６）ｃｍ￣２·ｓ￣（－１）。稀土离子还原为稀土金属的电位很负,以致在本底熔体分解前未出现阴极波。但在含ＣＯＣｌ＿２熔体中加入ＲＥＣ＿３（ＬａＣｌ＿３、ＴｂＣｌ＿３、ＤｙＣｌ＿３、ＴｍＣｌ＿３）,使钴的析出电位向正方移动,而且阴极电流增大,因而有可能发生ＲＥ（Ｌａ、Ｔｂ、Ｄｙ、Ｔｍ）与Ｃｏ的诱导共沉积。在尿素－ＮａＢｒ－ＫＢｒ－ＮａＯＡｃ－ＣｏＣｌ＿２－ＲＥＣｌ＿３熔体     

氯氧化镁在水中的溶解行为

用ｐＨ法和氯电位法测定氯氧化镁不同温度下在水中的溶解过程。一定间隔时间分析液样中的Ｍｇ＾２＋、Ｃｌ＾－、ＯＨ＾－的浓度，用物化方法鉴定固相。得出不同温度下的相转化、溶解的Ｃ￣ｔ曲线及动力学方程。计算了它们的Ｋｓｐ和热力学函数。     

复合催化剂AlCl3／SbCl3的α—蒎烯／苯乙烯阳离子聚合反…

用微臭氧化－薄层层析法分析测定了复合催化剂ＡｌＣｌ３／ＳｂＣｌ３在不同Ｓｂ比、投料比、溶剂和温度等条件下的α－蒎烯（Ｍ１）／苯乙烯（Ｍ２）共聚产物的构成。表明该复合催化剂可获得￣１００％共聚体，其中α－蒎烯链节含量Ｆ１可在３０％￣５６％之间调控。在仅生成共聚体的条件下由Ｍａｙｏ－Ｌｅｗｉｓ积分式首次测定了竞聚率。ＡｌＣｌ３／ＳｂＣｌ３和单独ＡｌＣｌ３相比，ｒ１增大，ｒ２减小，ｒ２／ｒ１值降低了５￣     

聚丙烯酰胺存在下Mohr法直接滴定碘、银等离子和硫氰酸根

1引言　　　　经典莫尔法对于　０．０１　ｍｏｌ／Ｌ的Ｃｌ－滴定误差达十０．６％需要进行指示剂的空白校正．且因　Ａｇｌ、ＡｇＳＣＮ沉淀强烈吸附Ｉ－和ＳＣＮ－、Ａｇ２ＣｒＯ４。沉淀凝聚后再转化成ＡｇＣｌ极慢，故不适于直接滴定Ｉ－、ＳＣＮ－、Ａｇ－。作者以聚丙烯酰胺（ＰＡＭ）化学修饰ＡｇＸ（ｘ－＝Ｉ－、ＳＣＮ－、Ｂｒ－、Ｃｌ－）及Ａｇ２ＣｒＯ４沉淀的结构，减小Ａｇｘ对Ｘ－的吸附与促进Ａｇ２ＣｒＯ４的转化，用莫尔法直接测定Ｉ－、ＳＣＮ－、Ａｇ＋及不需空白校正能准确滴定　０．０１　ｍｏｌ／ＬＣｌ－未见报道…     

阴离子交换纤维素膜、微晶纤维素膜作为室温燐光固体基质的评价对氨基马尿酸的固体基质室温燐光法的研究

本文评价了固体基质阴离子交换纤维素膜（ＤＥＡＥ膜）和微晶纤维素膜，且将此基质用于在重原子盐ＣｓＣｌ存在下，对氨基马尿酸的室温光法测定。重原子对ＲＴＰ有显著增强作用，且呈Ｃｓ￣＋＞＞Ｉ￣－＞Ｂｒ￣－＞Ｃｌ￣－的趋势。对有关的实验条件：烘烤温度、点样时机、介质ｐＨ、重原子浓度和ＲＴＰ稳定时间作了详细探讨。上述两种基质上，对氨基马尿酸的检出限和线性范围与滤纸上的结果相类似，特别是本文所得检出限均低于文献报道值。     

MoO_2Br_2体系催化丁二烯聚合中烯丙基卤素的作用

ＭｏＯ２Ｂｒ２－Ａｌ（ｉ－Ｂｕ）２ＯＰｈＣＨ３（－ｍ）体系催化丁二烯１，２－聚合过程中添加Ｃ３Ｈ５Ｘ（Ｘ＝Ｃｌ、Ｂｒ和Ｉ）对聚合物分子量有较好的调节作用，其中以Ｃ３Ｈ５Ｂｒ的调节作用最强，Ｍｎ从１７．５×１０５降至３．５×１０５，但对催化活性有一定的影响．在测定催化体系的ＵＶ光谱、（１３）Ｃ－ＮＭＲ谱、聚合活性和聚合动力学参数的基础上，讨论了Ｃ３Ｈ５Ｘ在催化体系中的行为．     

铬（Ⅵ）与5－溴水杨基荧光酮的显色反应及应用

本文研究了Ｃｒ（Ⅳ）与５－溴水杨基荧光酮（５－Ｂｒ－ＳＡＦ）的显色反应。在ｐＨ６．０ＫＨ＿２ＰＯ＿４－ＮａＯＨｉＬ冲溶液中，Ｃｒ（Ⅳ）与５－Ｂｒ－ＳＡＦ、ＣＴＭＡＢ形式稳定的三元络合物，其最大吸收波长为５７２ｎｍ，表现摩尔吸光系数为１．４２×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１）。Ｃｒ（Ⅳ）浓度在０～２．５μｇ／１０ｍＬ间服从比耳定律。用此法测定了环境水样中微量Ｃｒ（Ⅳ），获得满意结果。     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

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.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.