标题:Polyoxometaate-Engineered Nanostructures
报告时间:2024年7月19日(星期五) 9:30-10:30
报告地点:人民大街校区惟真楼230会议室
主讲人:lra Weinstock
主办单位:化学学院
报告内容简介:
Colloid science, and its more recent iteration as a branch of nanoscience, lies at theconceptual interace between molecular svstems and functional solid-state materials. Unlikemolecules, most colloidal structures are not amenable to characterization by single-crvstal X-ravcrystallography, while characterization of their surface features (such as protecting-liganddomains) lies outside the scope of the crystallographic methods used to define bulk phases ofsolidstate materials. As such, proaress in this area reauires a determined focus on theestablishment of reliable structurereactivity relationships. One approach, demonstrated in thepresent talk, is to use cryogenic transmission electron spectroscopy (cryo-TEM) to inyestiaatesoluble metal and metal-oxide nanostructures stabilized by readily imaged (highly electron dense)polytungstate (POM) cluster-anion ligands. The POM ligands simultaneously serve as "leavinggroups" for controlingthe transformations of the metal-nanoparticle ligand shells, and, forexample, guiding their self-assembly into supra-structures capable of host-guest chemistry.1Moreover, POMs can serve as coordinately linked anionic ligands for reactive metal-oxidenanocrystals, giving a new class of nanostructures uniquely positioned between molecularmacroanions and traditional colloids. While metal-oxide nanocrystals (NCs) are hiahlyreactivechallenging obstacles impede the systematic development of their solution-state chemistriesNamely, metal-oxide NCs are highly susceptible to precipitation in water. And, while organicligands impart stability, they block access to catalytically-active NC surfaces and lead to insolubleassemblies, Both these obstacles are overcome by replacing traditional organic ligands bywater-soluble cluster anions, This new family of soluble POM-complexed nanostructures wilbediscussed in the context of our larger vision of bringing reactive metal-oxide NCs into the tractableand flexible realm of solutionstate chemistry.
主讲人简介:
Ira A.Weinstock教授目前是以色列本古里安大学无机化学教授。1990年在麻省理工学院(MIT)获得博士学位,与Richard R.Schrock一起研究炔烃复分解。此后在新墨西哥州阿尔伯克基的桑迪亚国家实验室工作了一年后,在威斯康星州麦迪逊的美国农业部担任组长,在那里开始使用多金属氧酸盐作为绿色催化剂,用于水中生物量的好氧氧化。