TRANSITION-METAL-DOPED PLANAR BORON CLUSTERS: A NEW CLASS OF AROMATIC COMPOUNDS WITH HIGH COORDINATION
Loading...
Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Photoelectron spectroscopy in combination with computational studies over the past decade has shown that boron clusters possess planar or quasi-planar structures, in contrast to that of bulk boron, which is dominated by three-dimensional cage-like building blocks. All planar or quasi-planar boron clusters are observed to consist of a monocyclic circumference with one or more interior atoms. The propensity for planarity has been found to be due to both $\sigma$ and $\pi$ electron delocalization throughout the molecular plane, giving rise to concepts of $\sigma$ and $\pi$ double aromaticity. We have found further that the central boron atoms can be substituted by transition metal atoms to form a new class of aromatic compounds, which consist of a central metal atom and a monocyclic boron ring (Mopyright B$_n$). Eight-, nine-, and ten-membered rings of boron have been observed, giving rise to octa-, ennea-, and deca-coordinated aromatic transition metal compounds [1-3]. References: [1]"Aromatic Metal-Centered Monocyclic Boron Rings: Coopyright B$_9^-$ and Ruopyright B$_9^-$" (Constantin Romanescu, Timur R. Galeev, Wei-Li Li, A. I. Boldyrev, and L. S. Wang), Angew. Chem. Int. Ed. \textbf{50}, 9334-9337 (2011). [2]"Transition-Metal-Centered Nine-Membered Boron Rings: Mopyright B$_9$ and Mopyright B$_9^-$ (M = Rh, Ir)" (Wei-Li Li, Constantin Romanescu, Timur R. Galeev, Zachary Piazza, A. I. Boldyrev, and L. S. Wang), J. Am. Chem. Soc. \textbf{134}, 165-168 (2012). [3]"Observation of the Highest Coordination Number in Planar Species: Decacoordinated Taopyright B$_{10}^-$ and Nbopyright B$_9^-$ Anions" (Timur R. Galeev, Constantin Romanescu, Wei-Li Li, L. S. Wang, and A. I. Boldyrev), Angew. Chem. Int. Ed. \textbf{51}, 2101-2105 (2012).
Description
Author Institution: Department of Chemistry, Brown University, Providence, Rhode Island