Tri-tert-butyl methane and its halogen analogues: a computational study of intramolecular interactions in a family of sterically crowded molecules.

The gas-phase electron diffraction (GED) study of tri-tert-butyl methane (TTBM) published in 1972 by Bürgi and Bartell inspired the author to investigate the nature of the intramolecular interactions that are operative in this crowded hydrocarbon. Using the quantum theory of atoms in molecules (QTAIM), a topological analysis of the theoretical charge density of TTBM is carried out. Nine bond paths corresponding to the presence of noncovalent, intramolecular interactions operating at the interfaces that separate the three t-Bu groups do emerge from the QTAIM analysis. This result supports the existence of a network of intramolecular interactions predicted by Bürgi and Bartell in their landmark GED study of TTBM. In addition, the not yet synthesized halogen analogues (t-Bu)₃ CX (X=F to I) are also investigated herein. Some information about the remarkable contributions of the pioneers is provided throughout the paper. [ABSTRACT FROM AUTHOR]