Question

9. (14 points) Consider the CNN bond in the following molecule: NH H3C CH3 For each set of atom-centered orbitals shown: i. Identify the atomic orbitals or hybrids shown (e.g., p, sp3, etc.) in the box beneath each orbital ii. Clearly indicate the sign of the wave function by shading the appropriate lobes needed to generate the indicated molecular orbital. iii. Draw the orbital interaction that occurs between the two orbitals to form the indicated molecular orbital (o* or 7). Clearly indicate any nodes. H2C H Н4С atomic orbital: atomic orbital: molecular orbital: o Н.С., H N Hootc molecular orbital: atomic orbital: atomic orbital:

Answer 1

For the formation of the bonding  $\sigma$ MO the Sp2 hybrid orbitals should overlap in phase. That is both overlapping lobes should have same sign.

The Nitrogen and carbon have Sp2 hybridisation . Where the sigma bond is formed from the hybrid orbitals and $\pi$ bond formed by the lateral overap of unhybridised p orbitals.

The formation of antibonding $\pi*$ orbital occurs when the overlapping lobes have opposite phase or opposite sign.

I + H3C SP2 Sp2 H H3COM K H3C Р P