On the Importance of π-Hole Beryllium Bonds: Theoretical Study and Biological Implications.

In this study, the ability of beryllium compounds to establish π-hole bonding interactions has been evaluated at the RI-MP2/def2-TZVPD level of theory. A search of the Protein Data Bank revealed some X-ray crystal structures in which BeF3- moieties act as electron-acceptor entities. We have used [Mg(BeF3 )(HCOO)] (1) as a π-hole bond donor and CO, CH3 CN, NH3 , O(CH3 )2 , S(CH3 )2 , H3 PO, and glycine as electron-rich entities. In all cases, favorable binding energies were obtained, reflecting the attractive nature of the interaction involving the trivalent beryllium atom (-BeF3 moiety). In addition, we have used Bader's theory of "atoms in molecules" and noncovalent interaction (NCI) plot analysis to further investigate and characterize the π-hole complexes described herein. To the best of our knowledge, π-hole interactions involving beryllium have not hitherto been described in the literature.