Question

In terms of MO theory, which of species in each of the following pairs will most likely be the one to gain an electron? Explain your rationale.

a. CN or NO (Assuming the order of MO energy level diagram of NO follows that of N2)
b. (O2)2+ or (N2)2+

Answer 1

a. NO (nitrosyl) is more likely to gain an electron compared to CN (cyanide). This is because the electron density of the nitrogen atom in NO is higher, due to the presence of the unpaired electron in its lowest unoccupied molecular orbital (LUMO), which makes it a more attractive site for accepting electrons.

b. (N2)2+ is more likely to gain an electron compared to (O2)2+. This is because nitrogen atoms have a higher electronegativity compared to oxygen atoms, which means nitrogen attracts electrons more strongly. As a result, the electron density in the LUMO of N2 is higher, making it a more attractive site for accepting electrons.