Unexpected Stable Stoichiometries of Sodium Chlorides
化学
钠
无机化学
化学计量学
核化学
有机化学
作者
Weiwei Zhang,Artem R. Oganov,Alexander F. Goncharov,Qiang Zhu,Salah Eddine Boulfelfel,Andriy O. Lyakhov,Elissaios Stavrou,Maddury Somayazulu,Vitali B. Prakapenka,Zuzana Konôpková
出处
期刊:Science [American Association for the Advancement of Science (AAAS)] 日期:2013-12-20卷期号:342 (6165): 1502-1505被引量:404
Sodium chloride (NaCl), or rocksalt, is well characterized at ambient pressure. As a result of the large electronegativity difference between Na and Cl atoms, it has highly ionic chemical bonding (with 1:1 stoichiometry dictated by charge balance) and B1-type crystal structure. By combining theoretical predictions and diamond anvil cell experiments, we found that new materials with different stoichiometries emerge at high pressures. Compounds such as Na3Cl, Na2Cl, Na3Cl2, NaCl3, and NaCl7 are theoretically stable and have unusual bonding and electronic properties. To test this prediction, we synthesized cubic and orthorhombic NaCl3 and two-dimensional metallic tetragonal Na3Cl. These experiments establish that compounds violating chemical intuition can be thermodynamically stable even in simple systems at nonambient conditions.