title: Planar and pyramidal tetracoordinate carbon in organoboron compounds.
abstract: Using previously proposed C(BH)2(CH)2 (16, 17) and C(CH)2B2 (22) systems with a central planar tetracoordinate carbon (ptC) atom linking two three-membered rings as building blocks, a series of stable structures containing two and three ptC centers within a molecule have been designed and computationally studied with the DFT (B3LYP/6-311+G) method. Inclusion of a carbon atom ligated with pi-accepting and sigma-donating boron centers into at least one aromatic ring is critical for stabilization of a planar structure. A square pyramidal configuration at tetracoordinate carbon may be achieved in appropriately strained molecules such as [3.3.3.3]tetraborafenestrane 45 and others by surrounding the carbon with boron-centered ligands.
authors.affiliation: Institute of Physical and Organic Chemistry at Rostov State University, Southern Research Center of Russian Academy of Sciences, Rostov-on-Don, Russian Federation. minyaev@ipoc.rsu.ru
authors.forename: Ruslan M
authors.initials: RM
authors.lastname: Minyaev
authors.forename: Tatyana N
authors.initials: TN
authors.lastname: Gribanova
authors.forename: Vladimir I
authors.initials: VI
authors.lastname: Minkin
authors.forename: Andrey G
authors.initials: AG
authors.lastname: Starikov
authors.forename: Roald
authors.initials: R
authors.lastname: Hoffmann