Researchers discover a new Ccass of magic atomic clusters called superhalogens

An international team of researchers has discovered a new class of magnetic superhalogens - a class of atomic clusters able to exhibit unusual stability at a specific size and composition, which may be used to advance materials science by allowing scientists to create a new class of salts with magnetic and super-oxidising properties not previously found.

The discovery, which was published on 10 February in the Early View issue of the international chemistry journal Angewandte Chemie International Edition, was based on theoretical work by researchers from Virginia Commonwealth University, McNeese State University, and Peking University in China, and experimental work at Johns Hopkins University.

Unlike conventional superhalogens that are composed of a metal atom at the core and surrounded by halogen atoms, the magnetic superhalogens discovered by this team are composed of stoichiometric metal-halogen moieties at the core to which an additional halogen is attached.

The new chemical species known as magnetic superhalogens mimic the chemistry of halogens, which are a class of elements from the periodic table, namely, iodine, astatine, bromine, fluorine and chlorine. The word halogen means "salt-former," and when one of the elements above combines with sodium, they can form a salt.

Specifically, the cluster is MnxCl2x+1, where x = 1, 2, 3, and so on, have manganese and chlorine atoms as a core to which only one chlorine atom is attached. The manganese atoms carry a large magnetic moment and therefore make these superhalogens magnetic.

"One can now design and synthesise yet unknown magnetic superhalogens by changing the metal atom from manganese to other transition metal atoms and changing chlorine to other halogen atoms. In addition to their use as oxidising agents, being magnetic opens the door to the synthesis a new class of salts," said lead investigator Puru Jena, Ph.D., distinguished professor of physics at VCU.