An ELF and AIM study of NO2 and N2O4

The B3LYP/cc-pvtz approach is used to obtain Kohn-Sham wavefunctions for NO2 and N2O4 and several related compounds. ELF and AIM analyses on these systems lead to a better understanding of the unusual character of the NN bond in N2O4 in which competing Lewis structures with one or two electrons on the nitrogen atom in NO2 lead to a very weak sigma covalent bond that receives essentially no bonding contribution from the pπ part of the molecule.