Question

Construct a M.O. diagram for the radical OH

a. What type of MO contains the unpaired electron?

b. Is this orbital associated equally with both atoms or is it localized on a singleatom?

c. This first ionization energy of OH is 13.2 eV and that of HF is 16.05 eV.Explain.

Answer 1

The bond order for this ion is 1. Non bonding valence molecular orbitals 1 sigma and 1 pi.

In MO diagram of HF the 1 sigma and 2 sigma molecular orbitals of HF are mostly derived from the fluorine 2s and 2p atomic orbitals respectively. Due to the high fluorine character of these orbitals causes more electronegativity of fluorine compare to hydrogem thus the HF have high coefficients on fluroine and small coefficient on hydrogen. In case of HF and OH MO diagram differ in the relative energies of the atomic orbitals involved and in that there are nonbonding valence electron on the OH radical whereas in HF is not seen.