When two orbitals interact, their constructive and destructive interference produces stable and unstable orbitals, and the strength of the interactions determines the energy level of new orbitals as well as the energy gap between them. HOMOs in diazo compounds are considerably localized on the carbene fragment, whereas the LUMOs are predominantly located on the diazo moiety (Scheme 3(b)). Therefore, it can be inferred that the interaction between the carbene and diazo fragments contributes in some way to the formation HOMO and LUMO in diazo compounds. We expect HOMOs to be an indicator of the strength of the bonding between the diazo and carbene components. Accordingly, a diazo molecule with a more stable HOMO requires more activation energy to dissociate N 2 , implying a stronger interaction between the N 2 and carbene components. More negative partial charges on N2 in diazo compounds result in a lower energy barrier for N 2 dissociation. We choose 4 chemicals from backbone B to make it more understandable (Figure ). These compounds have -CF 3 , -F, -OMe, and -NMe 2 as R 1 functional group. The ability to donate electrons improves from the first to the last compound. The lower activation energy for molecule 2, compared to molecule 1, can be attributed to the presence of fluorine in the vicinity of the diazo group. Although fluorine acts as a strong σ electron-withdrawing group, it can also function as an effective π electron-donor. This competition between fluorine and diazo moiety to donate electrons to the empty p orbital of carbene weakens the electron transfer from nitrogen atoms. It means that the electron transfer from molecular nitrogen to carbon is reduced, and the electron density remains on the molecular nitrogen. Between the nitrogen atoms, the charge distribution on N1, which is directly bonded to carbon, is more sensitive to the electronic characteristics of the substitutions in diazo molecules. Meanwhile, the next nearest neighbor N, i.e. N2, atom to carbon remains less influenced by structural changes and shows a stronger correlation to the activation energy.