Computational Study of spx(x=1-3)-Hybridized Be-Be Bonds Stabilized by Amidinate Ligands.

The complexes containing odd-electron Be-Be bond are rare until now. Hereby, a series of neutral di-beryllium amidinate complexes containing Be-Be bond were explored theoretically. The complexes via the direct chelation with the Be 2 dimer by the bidentate amidinate (AMD) ligands are always corresponding to their global minimum structures. The detailed bonding analyses reveal the localized electrons of Be-Be fragment can be adjusted by the amount of AMD ligands because each AMD ligand only takes one electron from the Be 2 . Meanwhile, the hybridization of the central Be atom also changes as the number of AMD ligands increases. In particular, the sp 3 - hybridized single-electron Be-Be bond is firstly identified in tri- AMD ligands chelated neutral D 3h - Be 2 (AMD) 3 complex, which also possesses the higher stability compared to its monoanionic D 3h - Be 2 (AMD) 3 - and monocationic C 3 - Be 2 (AMD) 3 + . I mportantly, our study provides a new approach to obtain a neutral odd-electron Be-Be bond, namely by using of radical ligands through side-on chelation.