Energetic co-ordination compounds: synthesis, characterization and thermolysis studies on bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(III) perchlorate (BNCP) and its new transition metal (Ni/Cu/Zn) perchlorate analogues

Bis-(5-nitro-2H-tetrazolato-N2)tetraammine[cobalt(III)/nickel(III)] perchlorates (BNCP/BNNP) and mono-(5-nitro-H-tetrazolato-N)triammine [copper(II)/zinc(II)] perchlorates (MNCuP/MNZnP) have been synthesized during this work. The synthesis was carried out by addition of carbonato tetraammine metal [Co/Ni/Cu/Zn] nitrate [CTCN/CTNN/CTCuN/CTZnN] to the aqueous solution of sodium salt of 5-nitrotetrazole followed by reaction with perchloric acid. The precursors were synthesized by the reaction of aqueous solution of their respective nitrates with ammonium carbonate at 70 °C. The complexes and their precursors were characterized by determining metal and perchlorate content as well as infrared (IR), electron spectra for chemical analysis (ESCA) and X-ray diffraction (XRD) techniques. The TG profiles indicated that BNCP, BNNP and MNCuP are thermally stable up to the temperature of 260-278 °C unlike MNZnP (150 °C). Sudden exothermic decomposition was observed in case of bis-(5-nitro-2H-tetrazolato-N2)tetraammine cobalt(III) perchlorate, bis-(5-nitro-2H-tetrazolato-N2)tetraammine nickel(III) perchlorate and mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate resulting in the severe damage of the sample cup. Sensitivity data indicated that the Co/Ni/Cu complexes are more friction sensitive (3-4.8 kg) than mono-(5-nitro-H-tetrazolato-N)triammine zinc(II) perchlorate (14 kg). The impact sensitivity results of the complexes corresponded to h50% of 30-36 cm.