Prediction of donor–acceptor-type novel noble gas complexes in the triplet electronic state

Abstract

Closed-shell noble gas (Ng) compounds in the singlet electronic state have been extensively studied in the past two decades after the revolutionary discovery of ¹HArF molecule. Motivated by the experimental identification of very strong donor–acceptor-type singlet-state Ng complex ¹ArOH⁺, in the present article, for the first time, we report new donor–acceptor-type noble gas complexes in the triplet electronic state (³NgBeN⁺ (Ng = He–Rn)), where most of the Ng–Be bond lengths are smaller than the corresponding covalent limits. The newly proposed complexes are predicted to be stable by various computational tools, including coupled-cluster and multireference-based methods, with strong Ng–Be bonding (40.4–196.2 kJ mol⁻¹). We have also investigated ³NgBeP⁺ (Ng = He—Rn) complexes for the purpose of comparison. Various computational results, including the structural parameters, bonding energies, vibrational frequencies, and atoms-in-molecule properties suggest that it may be possible to prepare and characterize these triplet state complexes through suitable experimental technique(s).