2023 Volume 33 Issue 4 Pages 254-260
Pernitrides and polynitrides synthesized under high pressure, containing nitrogen dimers and molecular nitrogen, respectively, are a group of compounds quite different from conventional nitrides synthesized under ambient pressure. Transition-metal polynitrides composed of transition-metal and molecular nitrogen have been synthesized above about 100 GPa, and various types of molecular nitrogen have been discovered. Pernitrides containing nitrogen dimers have anisotropic axial compressibility in the bonding direction of the dimers due to the low compressibility of the dimers. In this article, we review recent progress in molecular nitrogen-containing metal compounds and the anisotropic compression behavior of a novel molybdenum–nitrogen compound, Mo3N5, containing nitrogen dimers.