title: Nature of the Xe(VI)-N Bonds in F6 XeNCCH3 and F6 Xe(NCCH3)2 and the Stereochemical Activity of Their Xenon Valence Electron Lone Pairs.
abstract: The recently reported syntheses and X-ray crystal structures of the highly endothermic compounds F6XeNCCH3 and F6Xe(NCCH3)2 ⋅CH3CN provide the first, albeit weakly covalent, Xe(VI)-N bonds. The XeF6 unit of F6 XeNCCH3 possesses distorted octahedral (C3v ) symmetry similar to gas-phase XeF6 , whereas the XeF6 unit of F6 Xe(NCCH3)2 ⋅CH3CN possesses C2v symmetry. Herein, the natural bond orbital (NBO), atoms in molecules (AIM), electron localization function (ELF), and molecular electrostatic potential surface (MEPS) analyses show that the Xe valence electron lone pairs (VELPs) of both compounds are stereochemically active. The Xe VELPS are diffuse and ineffectively screen their Xe cores so that the Xe VELP positions correspond to the most electrophilic regions of the MEPS, which enables the opposing N VELP of CH3CN to coordinate to this region. These bonds are predominantly electrostatic in nature and are interpreted as σ-hole interactions.
authors.affiliation: Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1, Canada.
authors.forename: Jamie
authors.initials: J
authors.lastname: Haner
authors.affiliation: Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1, Canada.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Matsumoto
authors.affiliation: Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1, Canada.
authors.forename: Hélène P A
authors.initials: HP
authors.lastname: Mercier
authors.affiliation: Department of Chemistry, McMaster University, Hamilton, ON, L8S 4M1, Canada. schrobil@mcmaster.ca.
authors.forename: Gary J
authors.initials: GJ
authors.lastname: Schrobilgen
keywords: computational chemistry; donor-acceptor systems; sigma-hole bonding; valence electron lone pairs; xenon chemistry