The team working with Michael Ruck at the Technical University of Dresden noticed this unexpected phenomenon while researching bismuth subhalides. Subhalides are compounds that have fewer halogen ions than pure ionic metal halides. This results in regions that contain direct bonds between metal atoms. Subhalides with bismuth and rhodium are known to have intermetallic substructures that range from clusters to three-dimensional networks. Bi12Rh3Cl2 contains intermetallic networks consisting of edge-sharing [RhBi8] cubes and antiprisms.
The researchers planned to “pull” the halogen atoms out without destroying the intermetallic regions under gentle conditions using an n-butyllithium solution. The chloride ions were extracted just as the scientists hoped, even though they seemed to be tightly enclosed by the narrow channels of the intermetallic network
Read more at: Phys.org