Theoretical study of hypervalent bonds in 1,6-diaza-1,6-dihydroand 1,6-dihydro-1,6-dioxapentalene systems with a heteroatom X at 6a position (X = 1416 group atoms)

The present study theoretically investigated hypervalent bonding systems with the skeleton of pentalene. Geometries and energetics were examined by density functional theory calculations with triple-zeta class basis sets. The bond energies of the OX and NX hypervalent three-center four-electron bonds were estimated. Furthermore, the relationships between the bond-switching equilibration reactions and the stabilities of the hypervalent bonding intermediates were examined.