# Can a "C"-"C" bond exist in a stable compound?

Oct 11, 2017

Yes it can... nearly every hydrocarbon proves that.

In any hydrocarbon containing two or more carbons, one must have a carbon-carbon bond.

${\text{H"_3"C"-"CH}}_{3}$

${\text{H"_3"C"-"CH"_2-"CH}}_{3}$

etc.

In all of these, carbon bonds with itself, and forms a stable compound.

Carbon cannot, however, form a stable ${\text{C}}_{2}$ molecule at room temperature.

Here, the MO diagram of ${\text{C}}_{2}$ suggests a Lewis structure of:

$: \stackrel{. .}{\text{C"=stackrel(..)"C}} :$

The formal charge on each carbon is $- 2$ and not $0$ like it would be for a nonpolar homonuclear diatomic molecule.

Its $\pi$ electrons are also in separate orbitals, so the $\pi$ bond I drew is really artificial. In reality the ${\text{C}}_{2}$ compound would then have two half-$\pi$-bonds using perpendicular sets of orbitals, so it's not quite a regular double bond overall...