Infrared Spectra of NgBeS (Ng = Ne, Ar, Kr, Xe) and BeS₂ in Noble-Gas Matrices

Laser-ablated beryllium atom has been codeposited at 4 K with hydrogen sulfide in excess noble gas matrices. Four noble-gas compounds NgBeS (Ng = Ne, Ar, Kr, Xe) and the BeS(2) molecule are identified on the basis of the S-34 isotopic substitution, DFT and CCSD(T) theoretical predictions, and a comparison of noble-gas substitution. The agreement between the experimental and calculated vibrational frequencies supports the identification of these molecules. The dissociation energies are calculated at 1.6, 12.6, 10.7, and 13.4 kcal/mol for NeBeS, ArBeS, KrBeS, and XeBeS, respectively, at the CCSD(T) level. The BeS Lewis acid molecule favors strong chemical binding between the Be and Ng atoms.