Syntheses, Crystal Structures and Properties of a Series of 3D Metal-Inorganic Frameworks Containing Pentazolate Anion

Pentazolate anion (cyclo-N-5(-)), and/or N-3(-), NO3- were used as the ligands to obtain a series of nitrogen-rich energetic three-dimensional (3D) frameworks [Cu(N-5)(N-3)](n), [Ag(N-5)](n), [Ba(N-5)(NO3)(H2O)(3)](n), and [NaBa3(N-5)(6)(NO3)(H2O)(3)](n) by self-assembly. These frameworks were characterized by single-crystal X-ray diffraction, SEM, IR and Raman spectroscopy, elemental analysis, and thermal analysis. All the frameworks exhibited regular supramolecular structures and excellent stabilities at room temperature which can be attributed to the strong coordination bonds between cyclo-N-5(-) anions and metal ions. The successful stabilization of the cyclo-N-5(-) in more 3D multi-ligand metal-N-5(-) frameworks after Na-N-5(-) frameworks has been demonstrated. This breakthrough offers new opportunities for the future of metal-pentazolate frameworks and polynitrogen chemistry.