What orbitals are used to form the carbon–carbon s bond between the highlighted carbons?
a.
b.
c.

In addition to radicals, anions, and cations, a fourth class of reactive intermediates is carbenes. A neutral species, the simplest carbene has a molecular formula of CH₂.

(b) What are the hybridization and shape of the central carbon of CH₂?

Predict the hybridization of the indicated atoms.

(b)

For the following partial structures, the σ bond is shown. Add the indicated number of π bonds, being sure to specify the orientation (that is, x, y, or z axis) of the p orbitals used.

(e)

Rank C―H σ the following bonds in terms of their bond length. Explain your ranking ( 1= longest ; 3 = shortest).

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

d.

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

f.

Predict the hybridization and geometry of the carbon and nitrogen atoms in the following molecules and ions. (Hint: Resonance.)

e.

What orbitals contain the electrons represented as lone pairs in the structures of purine, and pyrimidine?