Structural Analysis and Controllable Fabrication of Two Pentazolate-Based 3D Topological Networks

Area of Science:

• Inorganic Chemistry
• Crystal Engineering
• Materials Science

Background:

• The pentazolate anion (N5-) is a high-nitrogen content species with potential energetic applications.
• Exploring novel frameworks containing the pentazolate anion is crucial for understanding its coordination chemistry and structural diversity.
• Previous studies have focused on synthesizing stable pentazolate compounds, but controlling their framework topology remains a challenge.

Purpose of the Study:

• To synthesize and characterize two new sodium-pentazolate frameworks, MPF-3 and MPF-4.
• To investigate the influence of simple additives on the formation and structure of these frameworks.
• To explore the coordination modes and structural characteristics of the pentazolate anion within these novel frameworks.

Main Methods:

• Solvothermal synthesis utilizing sodium precursors, pentazole sources, and specific additives.
• Single-crystal X-ray diffraction for detailed structural determination of MPF-3 and MPF-4.
• Analysis of framework topologies, coordination environments, and guest molecule inclusion.

Main Results:

• MPF-3 was synthesized, featuring a 3D framework with zeolitic MTN topology and distinct Na28N80 and Na20N60 nanocages.
• MPF-4 was obtained, exhibiting a zeolite-like UNJ topology with left-handed helical chains and homochiral channels occupied by dimethyl sulfone.
• The study successfully demonstrated the role of additives in regulating crystal structure and accessing novel pentazolate frameworks.

Conclusions:

• The synthesis of MPF-3 and MPF-4 provides new platforms for studying the pentazolate anion.
• Additives are effective in controlling the crystal structure and topology of sodium-pentazolate frameworks.
• These findings open avenues for exploring the unique properties and potential applications of pentazolate-based materials.