Stabilization of the Pentazolate Anion in a Zeolitic Architecture with Na20N60 and Na24N60 Nanocages

The experimental detection and synthesis of pentazole (HN5) and its anion (cyclo-N-5(-)) have been actively pursued for the past hundred years. The synthesis of an aesthetic three-dimensional metal-pentazolate framework (denoted as MPF-1) is presented. It consists of sodium ions and cyclo-N-5(-) anions in which the isolated cyclo-N-5(-) anions are preternaturally stabilized in this inorganic open framework featuring two types of nanocages (Na20N60 and Na24N60) through strong metal coordination bonds. The compound MPF-1 is indefinitely stable at room temperature and exhibits high thermal stability relative to the reported cyclo-N-5(-) salts. This finding offers a new approach to create metal-pentazolate frameworks (MPFs) and enables the future exploration of interesting pentazole chemistry and also related functional materials.