Collect. Czech. Chem. Commun. 1988, 53, 2230-2238

On the nature of the bonding in X-Be-O molecules (X = He, Ne, Ar)

Pavel Hobzaa and Paul von Ragué Schleyerb

a Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6, Czechoslovakia
b Institut für Organische Chemie, Universität Erlangen-Nürnberg, D-8520 Erlangen, F.R.G.


The noble gas complexes, HeBeO, NeBeO, and ArBeO, discovered calculationally by Koch and Frenking, were reexamined at various theoretical levels. The results depended strongly on the size of the basis set but were insensitive to electron correlation corrections. The MP2 association energies of BeO with the noble gases, obtained with extended basis sets, were 4·80, 4·76, and 10·12 kcal/mol, respectively. The surprising stability of HeBeO (compared to NeBeO) is due to greater charge-transfer from He to BeO (donation) as well as to charge-transfer in the reverse direction (back donation). This compensates for the larger induction energy due to the greater polarizability of neon. The basis set superposition error is very large with split-valence basis sets; improvement of s and p function descriptions strongly reduces but does not completely eliminate this error.