Structure and Chemistry of Gas Phase Atomic Clusters

在化学系物理化学项目中，西北大学M·雅罗尔德教授将研究气相原子团的结构和化学。几何结构、结构异构体和结构转变将用改进的离子色谱技术来确定。此外，还将获得关于以前无法获得的特征的信息，例如团簇退火以及团簇异构化和经历相变的温度。团簇的热脱附测量将被用来解开原子团簇纳米表面上发生的化学，并确定准确的解离能和配体结合能。要研究的具体团簇系统将包括由100个以上碳原子组成的大型富勒烯类碳团簇和半导体团簇。原子(和分子)团簇构成一种聚集态物质，在凝聚态(固态或液态)和气态聚集态之间架起传统概念边界的桥梁。由于团簇的物理和化学性质不同于相关材料的凝聚相或气相，因此对团簇性质的研究具有重要的意义。除了探索团簇的内在兴趣外，还与团簇的技术应用有很强的耦合。富勒烯或巴克球是组成原子排列成三维测地线结构的团簇。富勒烯(或巴克球)是为了纪念巴克明斯特·富勒(Buckminster Fuller)而被赋予这种类型的星团的称谓，巴克明斯特·富勒以其测地圆顶的设计而闻名。除了众所周知的石墨和钻石之外，富勒烯现在被认为是一种新的第三种碳形式。对它们的物理和化学性质进行了深入的研究，以增加我们对它们的了解，并将其开发为技术应用。

In this project in the Physical Chemistry program of the Chemistry Division, Prof. M. Jarrold of Northwestern University will study the structure and chemistry of gas phase atomic clusters. Geometric structures, structural isomers, and structural transitions will be determined with an improved ion-chromatography technique. Additionally, information will be obtained on previously inaccessible features such as cluster annealing and the temperature at which clusters isomerize and undergo a phase transition. Thermal desorption measurements on clusters will be used to unravel the chemistry that occurs on the nano-surfaces of atomic clusters, and to determine accurate dissociation energies and ligand binding energies. Specific cluster systems to be studied will include large fullerene-type carbon clusters composed of more than 100 carbon atoms and semiconductor clusters. %%% Clusters of atoms (and molecules) constitute a form of aggregated matter that bridges the traditional conceptual boundary between the condensed (solid or liquid) and gaseous states of aggregation. Because the physical and chemical properties of clusters differ from those of the condensed or gaseous phases of the concerned material, the study of cluster properties is of fundamental interest. In addition to the exploration of cluster properties for their intrinsic interest, there is strong coupling to the technological applications of clusters. Fullerenes, or buckyballs, are clusters in which the constituent atoms arrange themselves to form three dimensional geodesic structures. The appellation fullerene (or buckyball) is given to this type of cluster in recognition of Buckminster Fuller who is known for his designs of geodesic domes. Fullerenes are now recognized to constitute a new, third form of carbon in addition to the well known forms graphite and diamond. Their physical and chemical properties are intensively investigated to increase our knowledge about them and to exploit it for technological applications.