Two new complexes based on 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ): Synthesis, crystal structure and properties

• Two new DNDZ complexes were synthesized, which is the first report of DNDZ complexes.
• Single-crystal structures of the two complexes were reported.
• Their properties were studied in detail, and compared with analogous FOX-7 complexes.

Two new energetic complexes, Zn(NH3)2(DNDZ)2 and Cu(NH3)2(DNDZ)2 [DNDZ = 2-(dinitromethylene)-1,3-diazacyclopentane], were first synthesized and structurally characterized. Zn(NH3)2(DNDZ)2 crystallizes in tetragonal crystal system with space group P4(1)2(1)2, but the crystal of Cu(NH3)2(DNDZ)2 is monoclinic with space group of C2/c. Zn2+ ion is coordinated by four N atoms from two NH3 molecules and two DNDZ− anions to form a distorted tetrahedron structure in Zn(NH3)2(DNDZ)2, while central Cu2+ ion coordinates with two O atoms and two N atoms from two DNDZ− anions and two N atoms of two NH3 molecules to form a six-coordinated octahedral structure in Cu(NH3)2(DNDZ)2. The thermal decomposition behaviors of the two complexes were studied with DSC and TG/DTG methods. Self-accelerating decomposition temperatures and critical temperatures are 164.7 and 166.4 °C for Zn(NH3)2(DNDZ)2, and 149.6 and 150.8 °C for Cu(NH3)2(DNDZ)2, respectively. The impact and friction sensitivities are >17.0 J and 36% for Zn(NH3)2(DNDZ)2, and >10.0 J and 56% for Cu(NH3)2(DNDZ)2, respectively. The two complexes exhibit lower sensitivity than analogous FOX-7 complexes.

Two new complexes based on 2-(dinitromethylene)-1,3-diazacyclopentane (DNDZ) were first synthesized and structurally characterized. Zn(NH3)2(DNDZ)2 crystallized in tetragonal crystal system with space group P4(1)2(1)2, but the crystal of Cu(NH3)2(DNDZ)2 is monoclinic with space group of C2/c.Figure optionsDownload as PowerPoint slide