硫化物的制备和转化

介绍硫化物的制备，转化和历程。     

四苯基苯吡啶基三苯基苯环四硅氧烷的合成

将四苯基环戊二烯酮或吡啶基三苯基环戊二烯酮分别与七甲基乙烯基环四环氧烷进行Ｄｉｅｌｓ－Ａｌｄｅｒ反应，生成了两种新的四苯基苯基七甲基环四硅氧烷和吡啶基三苯基苯基七甲基环四硅氧烷，用元素分析，ＩＲ，Ｒａｍａｎ和＾１Ｈ－ＮＭＲ作了表征。     

无机化学教学中涉及到的有毒物质

在无机化学教学中经常会遇到一些有毒物质，偶尔在实验室和生活中也会接触到，下面就分类加以阐述．     

硝基磺酚S分光光度法测定硝酸溶液中微量铌

在1molL~(-1)的硝酸介质中,硝基磺酚S与铌生成蓝色的络合物,其最大吸收波长是635nm,摩尔吸光系数是3.0×10~4,含铌量0～10μg/25ml范围内符合比尔定律,方法灵敏度高,探作简便、快速、易于掌握,用于测定硝酸溶液中微量铌获得满意结果。图6,表2,参4。     

核磁共振研究Ⅱ乙醛烯醇锂聚集体在溶液中的动态行为

对乙醛烯醇锂在四氢呋喃和四氢呋喃-正已烷混合溶中的动态行为进行了~(13)C和~1H核磁共振和~(13)C自旋-晶格弛豫时间的研究。在这些溶剂中,乙醛烯醇锂能以两种溶剂化程度不同的非刚性四聚体同时存在,两种聚集体间的转换在低温下慢于NMR时标,温度对平衡的影响很小。在溶液中,聚集体整体运动是各向同性的;与此同时,乙烯基在聚集体内作快速内旋转。聚集休整体重取向运动和乙烯基内旋转的势垒分别为8.5±0.7 KJ·mol~(-1)和6.6±1 KJ·mol~(-1)。     

Study on Soap-free P（MMA-EA-AA/MAA） Latex Particles With Narrow Size Distribution

In the past decades, more and more studies have been focused on the synthesis of monodisperse particles with different diameter by special polymerization technique. In 1980＇ s, Ugelstad, et al invented two-step swelling method to prepare monodisperse microsphere with large size more than 1μm. In the following decade, Okubo and his coworkers synthesized monodisperse crosslinked polymer particles above 3μm using one-step dynamic swelling method. New method has been developed to produce particles more than 50 gm in diameter with a standard deviation of less than 2 % . Up to now, most of the monodisperse particles were usually prepared by polymerization of St in the presence of surfactants. In this presentation, sub-micro sized P （MMA-EA-AA/MAA） particles with narrow size distribution were prepared by seeded emulsion polymerization in the absence of any surfactant materials.