Inert gas helium known for its hesitancy to react with other elements has developed a very stable new compound known as sodium helide. This was produced by placing helium under high pressure to react with sodium in high temperature.
Properties Not Known
Boldyrev along with his doctoral student Ivan Popov were part of an international team of scientists, led by Artem Oganov of Stony Brook University, who conducted the research on helium. They have published their research in Nature Chemistry.
Yet, the new compound’s properties have not been completely understood with practical applications.
But, the new compound will pave the way for researchers to produce new unusual materials in lower pressures.
Attempts to make compounds with helium started in the 1960s despite its hesitancy. As a least reactive element, helium was incapable of forming chemical compounds. Although xenon compounds were made from helium, they were all short lived.
How Was It Done?
Before conducting the reaction of helium with sodium, scientists led by Artem Oganov of Stony Brook University in New York done necessary computer calculations to know what all compounds can be prepared from helium. The study revealed that sodium can react with helium if it can be compressed under high pressure.
During the study, Goncharov and colleagues mixed a small quantity of helium and sodium between a pair of diamonds and increased up pressures million times the atmospheric pressure of Earth. After that, the material was heated with lasers having temperatures above 1200° Celsius. The X-rays that were produced gave a hint about the compound’s structure that was similar to computer predictions.
The unique compound is an electride and has bizarre nature, sodium helide acts like a commonplace compound where chloride ions are negatively charged. While the isolated electron pairs act like negative ions, the eight sodium atoms covering each helium atom will be acting as positive ions.
According to computer calculations, the possibility of forming a compound of helium, sodium and oxygen, called Na2HeO, at lower pressures was also appropriate.