CAl4Mg0/?: Global Minima with a Planar Tetracoordinate Carbon Atom

Isomers of CAl4Mg and CAl4Mg? have been theoretically characterized for the first time. The most stable isomer both neutral anion contain a planar tetracoordinate carbon (ptC) atom. Unlike isovalent CAl4Be case, which contains pentacoordinate atom as global minimum geometry, replacing beryllium with magnesium makes ptC due to increased ionic radii magnesium. However, it is relatively easier conduct experimental studies CAl4Mg0/? toxic. While molecule containing follows 18 valence electron rule, breaks rule 19 electrons. affinity in range 1.96–2.05 eV. Both minima exhibit ?/? double aromaticity. Ab initio molecular dynamics simulations were carried out at 298 K 10 ps confirm their kinetic stability.