Noble Gas Anions:  A Theoretical Investigation of FNgBN^-(Ng = He−Xe)

Abstract

Noble gas anions of general formula FNgBN- (Ng = He-Xe) have been investigated by MP2, coupled-cluster, and multireference-CI calculations with correlation-consistent basis sets. These species reside in deep wells on the singlet potential energy surface and are thermodynamically stable with respect to the loss of F, F-, BN, and BN-. They are unstable with respect to Ng + FBN-, but at least for Ng = Ar, Kr, and Xe, the involved energy barriers are high enough to suggest their conceivable existence as metastable species. The stability of FNgBN- arises from the strong F--stabilization of the elusive NgBN. The character of the boron-noble gas bond passes from purely ionic for FHeBN- and FNeBN- to covalent for FXeBN-.

On the position of helium and neon in the Periodic Table of Elements

“…Notably, a hypothetical (F -ÁÁÁNeBN) anion remains the only metastable anionic species which contains chemically bound Ne atom-an analogous He species is predicted to be much more strongly bound (Antoniotti et al 2007). The inertness of neon has been traditionally assigned to the Pauli repulsion involving 2p shell-note: helium lacks p electrons, hence Pauli repulsion is greatly reduced.…”

Cationic Noble Gas Hydrides: A Theoretical Investigation of Dinuclear HNgFNgH+(Ng = He−Xe)

“…It confirms in fact that these two elements, usually reluctant to form neutral compounds, can be fixed into ionic fragments (especially cationic but also anionic) so as to form tightly bound species. [51][52][53][54] It is also of interest to note that the CCSD(T)/ aug-cc-pVTZ/SDD H-Ng distances of the HNgFNgH + cations are quite similar to the H-Ng distances of the recently investigated HNgCO + cations 19 and follow, for any Ng, strictly analogous trends with respect to the diatomic HNg + . The geometries of the linear HNgFNgH + can be also compared with the neutral HNgF.…”

Theoretical investigation of HNgNH3+ ions (Ng = He, Ne, Ar, Kr, and Xe)

“…[50][51][52] In particular, ArBF 2 + was first predicted by Chen et al 53 and was subsequently detected by Levee et al 54 Over the past few years, new bonding arrangements involving Ng atoms in charged species were also observed and analyzed, i.e., XeF 3 − , 55 64 and C 7 H 6 He n 2+ (n = 1 and 2). 65 These findings strongly support the theoretical work conducted in this area.…”