Pentazolate coordination polymers self-assembled by in situ generated [Pb4(OH)4]4+ cubic cations trapping cyclo-N5−

Abstract

A series of cyclo-N₅⁻-based lead-containing energetic coordination polymers [Pb(OH)]₄(N₅)₄ (1), [Pb₃(N₅)₃(H₂O)₉(NO₃)]₄(N₅)₈(H₂O)₅ (2), [Pb(OH)]₄(N₅)₃(NO₃)(H₂O)₃ (3), and [Pb(OH)]₄(N₅)₃(ClO₄)(H₂O) (4) were synthesized by self-assembly and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared and Raman spectroscopy, high resolution mass spectrometry, elemental analysis, scanning electron microscopy, and differential scanning calorimetry. In addition, their thermal decomposition kinetics have been studied theoretically and experimentally. The results revealed that the synthesized CPs possess regular structures, very high densities (2.852–4.537 g cm⁻³), good oxygen balances (CO₂) (−2.72–+2.61%), good thermal stabilities (80–110 °C), and acceptable sensitivities (9.5–20 J; 120–240 N). This work will provide new inspiration for the development of cyclo-N₅⁻-based coordination polymers and energetic materials.