Nanodisperse systems as transient state upon the formation of crystalline organometalsiloxanes

Properties of colloidal solutions formed in the course of hydrolytic condensation of phenyltrialkoxysilanes are studied upon the synthesis of organosiloxanolates of alkali metals and cage-like bimetallic organometalsiloxanes containing alkali and transition (Ni, Cu) or rare-earth (Eu) metals. Sizes and shapes of particles are determined by the dynamic and static light scattering methods. The aggregation stability of colloidal solutions is studied as a function of solvent nature and concentration of phenyltrialkoxysilane. Data obtained make it possible to suggest that disclosed aggregates are the nuclei of crystalline phase. Conditions of the existence of stable colloidal aggregates of sodium phenylsiloxanolate and Ni/Na-phenylsiloxane are determined. It is shown that, upon the dissolution of crystalline Ni/Na-phenylsiloxane in butanol, particles whose sizes are comparable with molecules of organometalsiloxanes are formed in the initial solution.     

二氢苯骈[c]菲啶类生物碱的制备及其抗乙肝病毒的活性

二氢苯骈[c]菲啶类生物碱是自然界中一类重要的生物活性成分,但含量很低.利用硼氢化还原方法,对博落回粗提物中的血根碱和白屈菜红碱混合物进行还原、分离,得到了二氢血根碱和二氢白屈菜红碱;并初步评价了其抗乙肝病毒活性.结果表明,利用硼氢化还原方法制备二氢苯骈[c]菲啶类生物碱的产率较高,还原产物具有一定的抗乙肝病毒活性.     

电沉积种子层化学控制生长氧化锌纳米棒和纳米管

采用水溶液法在电沉积的ZnO种子层上制备了高度取向的ZnO纳米棒阵列,并通过碱溶液化学腐蚀法获得了ZnO纳米管。对ZnO纳米棒和纳米管的溶液生长和腐蚀过程进行了分析。结果表明,种子层的结构和性能对ZnO纳米棒有着重要的影响,在-700 mV电位下沉积的种子层薄膜均匀性好,生长的纳米棒密度大、与基底垂直性好;碱溶液对纳米棒的腐蚀具有选择性,通过控制腐蚀液的浓度和时间,可获得中空的ZnO纳米管。     

ChemInform Abstract: Crystal Structures of New Ternary Rare Earth Silicides Sc3Pr2Si4, Sc1.26Pr3.74Si4 and Sc3.96Nd1.04Si4 with Ordered and Partially Ordered Rare Earth Sites.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

ChemInform Abstract: Crystal Structure of Zr9Co7In14.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.