Lithium nitride is a pretty unique substance. (It’s not really a molecule, title of this post not withstanding.)
It’s formed by the combustion of lithium metal in a nitrogen atmosphere, which is already pretty cool – what else “burns” in pure nitrogen? (Hint: magnesium.) Although a solid, lithium nitride is a fast ion conductor, and is being explored as a solid-phase electrolyte for lithium-ion batteries. Pretty sweet? Check.
The “nitride” anion is powerful enough a base to deprotonate hydrogen gas, forming hydride. This property means lithium nitride (and related materials) could be useful as a H2 storage material if we ever wind up with an H2 economy. Awesome? Check. (That is, lithium nitride is awesome, not an H2 economy.)
And, solutions of lithium nitride in molten alkali chlorides can be used for electrochemical fixation of nitrogen, generating ammonia from atmospheric nitrogen at atmospheric pressure and 300 °C. Compare that to the ~200 atm pressure needed for industrial ammonia synthesis. Pretty sweet? I think so.
Lithium nitride: its that molecule you’ve been hearing about!