Theoretical Study on Neutral Molecules with Square Planar Tetracoordinate Oxygen O(B)4 Arrangements

[Image: see text] As we know, oxygen usually forms two single bonds with other atoms, whereas in this work, we reported the neutral molecules with square planar O(B)4-type tetracoordinate oxygen substructures. The difficulty to achieve a square planar O(B)4-type arrangement is not only to overcome the strain from the planar to tetrahedral configuration but also to constrain it in a right system with the proper symmetry. Several neutral molecules with square planar O(B)4-type arrangements have been studied using the DFT method at the B3LYP/6-311++G(3df,3pd) level of theory. The computational results show that they are all real minima on potential energy hypersurfaces. Thus, it has been shown theoretically that the square planar O(B)4-type arrangement is achieved. The molecular orbitals among the square planar O(B)4-type substructure at D(2d) symmetry have been suggested. Using the molecular orbitals, it has been explained that the oxygen 2p(z)-π electrons in the square planar O(B)4-type arrangement are no longer the lone-pair electrons.