Alexander I. Boldyrev

In 1874 independently J. H. van't Hoff and J. A. LeBel recognized that the tetracoordinated tetravalent carbon atom prefers a tetrahedral arrangement of its substituents. This contribution marks a milestone in understanding the structure of carbon compounds. While the tetracoordinated tetrahedral carbon is firmly established in chemistry and biochemistry and elegantly explained by the concept of sp3-hybridization, chemists have for many years attempted to make compounds containing planar tetracoordinated carbon. We were able not only to predict computationally pentaatomic molecules with tetracoordinated planar carbon, but also helped to prove the planarity of the first gas-phase made of two pentaatomic tetracoordinated planar carbon molecules, CAl3Si and CAl3Ge which were investigated by a combination of ab initio calculations (by us) and anion photoelectron spectroscopy by (L.-S. Wang with co-workers, PNNL and WSU).