text: Some Zintl ions show the ability to activate small molecules. One example from Dehnen and coworkers is the capture of O by the intermetallic cluster [Bi{Ru(cod)}]. Another ruthenium intertermetallic cluster, [Ru@Sn], was used as a precursor to selectively disperse the CO hydrogenation catalyst Ru-SnOx onto CeO, resulting in nearly 100% CO selectivity for methanation.
  In materials science, Ge has been used as a source of Ge in lithium ion batteries, where is can be deposited in a microporous layer of alpha-Ge. The discrete nature of Zintl ions opens the possibility for the bottom up synthesis of nanostructured semiconductors and the surface modification of solids. The oxidation and polymerization of Zintl ions may also be a source of new materials. For example, polymerization of Ge clusters was used to create guest free germanium clathrate, in other words a particular, pure Ge.