B<sub>3</sub>H<sub>3</sub>Be ← F<sup>–</sup>: A Case of Extremely Strong\nDative Bond

Chemical bonding has attracted chemists since its inception.\nDative\nbonding between a donor and acceptor moiety is also an important phenomenon,\nwhich results in stabilization of many chemical compounds. Herein,\nwe show that an extremely strong dative bond is possible between a\nfluoride ion and a beryllium center which is a part of a half-sandwich\ncomplex, B<sub>3</sub>H<sub>3</sub>Be. Quantum chemical calculations\nhave shown the possibility of formation of a half-sandwich complex\nof Be with a B<sub>3</sub>H<sub>3</sub><sup>2–</sup> ring.\nCalculations reveal that the complex is stable toward dissociation.\nThe half-sandwich complex features a very low-lying lowest unoccupied\nmolecular orbital (LUMO) concentrated on the Be atom, thereby indicating\na Lewis acidic character of the complex. This lower-lying LUMO at\nthe beryllium center is responsible for forming an extremely strong\ndative bond with the fluoride donor.