Hepta-coordinated vanadium stabilized alkaline earth dimers: a DFT study

Two hepta-coordinated vanadium carbonyl ligands stabilise alkaline earth metal (Ae; Ae = Be, Mg, Ca, Sr, Ba) dimers in the Ae₂²⁺ form in Ae₂[V(CO)₆]₂ complexes. The stability of these complexes is confirmed by density functional theory-based calculations, and the existence of Ae₂²⁺ units is supported by various charge analysis methods. Atoms-in-molecules (AIM) and electron localization function (ELF) analyses indicate the covalent nature of the Ae-Ae bond, whereas the Ae⋯V interactions are noncovalent. Natural bond orbital (NBO) results further confirm the ionic nature of the Ae⋯V interactions, a conclusion corroborated by energy decomposition analysis (EDA). A comprehensive investigation of the Ae₂[V(CO)₆]₂ complexes, demonstrating their viability and stability, is presented.