Theoretical Study of Multi-Coordinated Xe(AuF)n (n = 2-4): Intriguing
Bond-bending Isomerism
Abstract
This work reports a theoretical study of a novel family of
multi-coordinated noble gas (Ng) complexes, Xe(AuF)n (n = 2-4).
Geometrical optimization at the LC-ωPBE-D3/def2TZVPP level locates two
types of structures based on the bond-bending isomerism induced by an
intramolecular competition between Xe-Au covalent bonding and Au···Au
aurophilic interactions. They both comprise a center Xe atom serving as
an electron donor binding to AuF moieties, but pronouncedly differ in
the Au-Au distance and Au-Xe-Au bending angle. Comprehensive chemical
bonding analysis undisputedly demonstrates that aurophilic interactions
exist and affect the strength of Xe-Au bonds whose covalent nature is
evident. By scanning the potential energy surface of Xe(AuF)2 with
arbitrary one atom being substituted by its analogue, we found only
Xe(AuF)2 and Xe(AuCl)2 feature bond-bending isomerism, due to the highly
electronegative F/Cl atom inducing strongly covalent Xe-Au bond via
electron donation-feedback mechanism. The present work predicts
multi-coordinated Ng-metal complexes and demonstrates the bond-bending
isomerism, which could be an interesting addition and call out more
attentions to the research field of Ng chemistry.