Beryllium Dimer Reactions with Acetonitrile: Formation of Strong Be-Be Bonds.

Laser ablated Be atoms have been reacted with acetonitrile molecules in 4 K solid neon matrix. The diberyllium products BeBeNCCH 3 and CNBeBeCH 3 have been identified by D and 13 C isotopic substitutions and quantum chemical calculations. The stabilization of the diberyllium species is rationalized from the formation of the real Be-Be single bonds with bond distances as 2.077 and 2.058 Å and binding energies as -27.1 and -77.2 kcal/mol calculated at CCSD (T)/aug-cc-pVTZ level of theory for BeBeNCCH 3 and CNBeBeCH 3 , respectively. EDA-NOCV analysis described the interaction between Be 2 and NC···CH 3 fragments as Lewis "acid-base" interactions. In the complexes, the Be 2 moiety carries positive charges which transfer from antibonding orbital of Be 2 to the bonding fragments significantly strengthen the Be-Be bonds that are corroborated by AIM, LOL and NBO analyses. In addition, mono beryllium products BeNCCH 3 , CNBeCH 3 , HBeCH 2 CN and HBeNCCH 2 have also been observed in our experiments.