Observation of Metal-Centered Monocyclic Boron Rings: A New Class of Aromatic CompoundsLai-Sheng Wang, Brown University, DMR 0904034 Prior research supported by this program has shown that small boron clusters form interesting planar structures. These clusters all feature a circumference characterized by strong two-center-two-electron B-B bonds and one or more interior atoms interacting with a boron ring via delocalized bonding. We have found recently that the central boron atoms can be replaced by transition-metal atoms, forming a new class of aromatic compounds. Photoelectron spectroscopy experiments and theoretical calculations show that CoB8– and RuB9– possess perfect D8h and D9h symmetries with the metal atoms stabilizing a B8 and B9 monocyclic ring, respectively. The bonding between the central metal atom and the boron ring is described by six delocalized s electrons and six delocalized p electrons, resulting in double aromaticity. These clusters represent examples of a potentially large class of aromatic planar transition-metal complexes with novel coordination environments and chemical properties . Optimized structures of CoB8–, CoB8, RuB9–, and RuB9 using density functional calculations  C. Romanescu, T. R. Galeev, W. L. Li, A. I. Boldyrev & L. S. Wang, Angew. Chem. Int. Ed.50, in press (2011)
Organization and Co-Chairing of the 2011 Gordon Research Conference on Clusters, Nanocrystals & Nanostructures Lai-Sheng Wang, Brown University, DMR 0904034 Please describe in this second slide some notable broader impacts from your grant in the current year. These may include education, outreach, broadening participation of underrepresented groups, societal and technological outputs, industrial or international collaborations, development of infrastructure or instrumentation, organization of workshops or symposia, etc. PLEASE REMEMBER TO NAME YOUR FILE AS FOLLOWS: “Award number_(underscore) Last name.ppt”, e.g. 0898934_Smith.ppt PLEASE DO NOT EXCEED 1 MB PER SLIDE Please insert an image (.JPEG) or group of images here to illustrate your broader impacts activities. If you need more space, you may reduce the adjacent textbox. Please use lettering that is clearly visible (i.e. not too small). Please include a brief figure caption.