Bonding Analysis of Compounds with Unusual Coordination of Carbon: Proposed Symmetric Systems with Six-Coordinate Carbon

Carl Trindle; Zikri Altun; Erdi Ata Bleda

doi:10.3390/molecules25173937

Bonding Analysis of Compounds with Unusual Coordination of Carbon: Proposed Symmetric Systems with Six-Coordinate Carbon

Molecules. 2020 Aug 28;25(17):3937. doi: 10.3390/molecules25173937.

Authors

Carl Trindle¹, Zikri Altun², Erdi Ata Bleda²

Affiliations

¹ Chemistry Department, University of Virginia, Charlottesville, VA 22904, USA.
² Physics Department, Marmara University, Istanbul 34724, Turkey.

Abstract

The possibility of carbon tetravalence in geometries other than tetrahedral and of carbon hypervalence has been taken seriously since the 1970s. Computational modeling and subsequent experimental validation have established the existence of molecules with carbon atoms with planar tetravalence and as many as six objects in carbon's coordination sphere. In this work, we develop insight into the nature of bonding to carbon in these unusual environs as provided by Bader's Atoms in Molecules (AIM) analysis of the electron density, along with the electron localization function (ELF) and the non-covalent index (NCI). We review several well-established systems (spiropentadiene dication, hexamethyl benzene dication, dimethanospiro[2.2]octaplane dication, and 1,8-dimethoxy-9-dimethoxyanthracene cation) and propose new D_2d-symmetric variants of a hexacoordinated species.

Keywords: AIM modeling; carbon hypercoordination; electron localization function; non-covalent interaction.

Publication types

Review

MeSH terms

Algorithms
Benzene Derivatives / chemistry
Carbon / chemistry*
Electrons
Models, Chemical*
Models, Molecular*
Molecular Dynamics Simulation
Molecular Structure*
Software

Substances

Benzene Derivatives
Carbon
hexamethylbenzene