Diazomethane

$\mathrm{C}{\mathrm{H}}_2{\mathrm{N}}_2$, with a linear C–N–N skeleton and a planar carbon environment. Important resonance contributors are ${\mathrm{H}}_2\mathrm{C}={\mathrm{N}}^{+}={\mathrm{N}}^{-}$ and ${\mathrm{H}}_2{\mathrm{C}}^{-}-{\mathrm{N}}^{+}\equiv \mathrm{N}$.