Synthesis of AgN₅ and its extended 3D energetic framework

Area of Science:

• High-energy density materials
• Polynitrogen chemistry
• Inorganic synthesis

Background:

• The pentazolate anion (N5-) is a promising high-energy density material.
• Minimizing non-energetic components in pentazole complexes is crucial for increasing energy density.

Purpose of the Study:

• To report a solvent-free pentazolate complex, silver pentazolate (AgN5).
• To synthesize a 3D energetic framework using silver and the cyclo-N5- anion.
• To advance pentazole chemistry by isolating a cyclo-N5- complex without stabilizing molecules or ions.

Main Methods:

• Solvent-free synthesis of silver-based pentazolate complexes.
• Characterization of a 3D energetic framework: [Ag(NH3)2]+[Ag3(N5)4]-.
• Thermal stability analysis up to 90°C.

Main Results:

• Successful synthesis of a solvent-free AgN5 complex and a 3D energetic framework.
• Complexes exhibit stability up to 90°C, decomposing into silver (Ag) and nitrogen gas (N2).
• Evidence for AgN5 formation despite challenges with isolation due to decomposition to AgN3.

Conclusions:

• The isolation of a cyclo-N5- complex devoid of stabilizing agents represents a significant advancement in pentazole chemistry.
• The synthesized materials show potential for explosive and propulsion applications due to their high energy density.
• Solvent-free synthesis offers a pathway to more energy-dense polynitrogen materials.