text: Plumbides can be formed when lead forms a Zintl phase compound with a more metallic element. One salt that can be formed this way is when cryptand reacts with sodium and lead in ethylenediamine (en) to produce [Pb], which is red in solution.
  Lead can also create anions with tin, in a series of anions with the formula [SnPb].
  Lead can also form the [Pb] anion, which is emerald green in solution.