A team of researchers at Stony Brook University, led by professor of theoretical crystallography Dr. Artem Oganov, found compelling evidence that redefines fundamental rules of chemistry.
It is well outlined in textbooks and universally accepted that when sodium (Na) and chlorine (Cl-) are combined, NaCl, also known as table salt, forms with a ratio of 1:1. This is because the opposite and equal charges attract each other.
This principle is widely taught in high school and college classrooms, yet the recent study by Oganov provides evidence that entirely different compounds with altered ratios are formed when sodium and chloride are combined in low pressure environments.
Predicted using a computer code developed by Oganov and then verified by collaborators at Carnegie Institution of Washington, Oganov’s findings raise questions about the current understanding of chemistry and the rules we use to govern it.
In addition to the expected NaCl, other compounds like NaCl3, NaCl7, Na3Cl2, Na2Cl, and Na3Cl also formed. Even though these compounds do not satisfy the rule of having the correct number of electrons, once they are formed, they remain indefinitely.
According to classical rules of chemistry, these compounds are impossible, yet they exist and are relatively stable. Furthermore, according to Oganov, the compounds produced may lead to “the creation of new materials with unusual properties and applications.”
For example, Na3Cl has a structure similar to a layer cake in that there are layers of NaCl and layers of pure sodium, instead of icing and cake. The NaCl layers serve as insulators while the pure sodium layers conduct electricity. These dual properties create a myriad of useful applications for this new compound.
These findings might also help explain anomalies in the planetary sciences. Pressures in space vary widely and are even more drastic than those Oganov used in the lab. Therefore, Oganov believes that his findings might help to explain “the possible existence of totally unexpected compounds in planetary interiors.”
When asked about the findings Oganov said that “every little bit of this study was a huge surprise.” He and his team plan to explore other similar systems in an effort to craft new rules that will be applicable to this new class of compounds.
Correction: Jan. 29, 2014
An earlier version of this article incorrectly explained how sodium and chlorine join to form a bond.