Superman has to start worrying: has the formula for kryptonite been found?

Chemists managed to figure out how to synthesize the two-component compound of krypton and oxygen - krypton oxide. It turns out that this exotic substance can be produced under conditions of high pressure, and it is certainly possible within the chemical capabilities of the laboratories today.

Researchers in the field of theoretical chemistry from the Institute of Physical Chemistry at the Polish Academy of Sciences found how to synthesize the two-component compound of krypton and oxygen - krypton oxide. It turns out that this exotic substance can be produced under conditions of high pressure, and it is certainly possible within the chemical capabilities of the laboratories today.

Crystals of kryptonite, a deadly substance for Superman and his race, is produced on the planet Krypton, so it is likely that it is obtained under high pressure. The origin of the name, krypton, is an element in Mendeleev's periodic table with an atomic number of 36, a noble gas considered as such that stable compounds cannot be made from it. At the same time, an article recently published in the scientific journal Scientific Reports Describes the possibility of synthesizing a new crystalline material in which krypton atoms will be bonded to atoms of another type. "The substance that we predict as a possibility is a compound of krypton with oxygen. According to the comic book, therefore, the substance should be called cryptoxide and not kryptonite. Our krypton monoxide, KrO, apparently does not exist in nature. In the past, it is true that krypton compounds were synthesized in the laboratory, but only under freezing conditions. However, these were small, linear and single molecules whose composition consisted of hydrogen-carbon-krypton-carbon-hydrogen. The Polish chemists wondered if there were conditions under which krypton atoms would react with other types of atoms to form a stable and extensive crystal lattice.

"Our computer simulations show that crystals of krypton monoxide can form at pressures ranging from 500 to 300 million atmospheres. Although this pressure is particularly enormous, it can be reached in the laboratories operating today by compressing the material samples between anvils made of diamond," says the chief researcher. Crystal lattices consist of atoms or molecules arranged in space in a periodic manner. The smallest repeating segment in such structures - the basic building block - is called a 'unit cell'. In crystals of table salt (composed of sodium and chlorine atoms), for example, the unit cell is in the form of a cube. The unit cell of krypton monoxide is in the structure of a box. The researchers found another possibility for a second, less stable krypton compound - krypton tetraoxide - KrO4. This material, whose properties are probably similar to those of a typical metal, has a simple crystalline structure and can be created under pressure conditions of 350 million atmospheres. Once made, both types of krypton oxides would probably be able to exist at a lower pressure than the one at which they were formed. At the same time, the pressure on the Earth's surface is so low that these crystals, if they were indeed formed, would undergo rapid dissolution. "Reactions that occur at extremely high pressure are almost unknown. We call chemistry of this type "fringe chemistry". Often the pressure required to prepare such compounds is so enormous that today there is no point in trying to prepare them in a laboratory.

The full article

to the announcement of the Polish Academy of Sciences

The three most stable structures calculated within the computer simulations for krypton monoxide (KrO) at a pressure of 300 gigapascals. The red circle symbolizes an oxygen atom, while the gray one is a krypton atom.