Study of physical and chemical properties in some energetic materials from the tetrazole family by the 14N NQR

Some recently designed energetic materials are based on the tetrazole ring CH2N4. It seemed to us worth to get an insight into basic properties of this starting material. We applied the nitrogen nuclear quadrupole resonance (N-14 NQR) spectroscopy as a method to examine some physical and chemical properties of 5-aminotetrazole and 5-aminotetrazole monohydrate. N-14 NQR frequencies and spin-lattice relaxation times were measured at different temperatures between 77K and 300K. Five NQR triplets v(+), v(-) and v(0) were found for the five in-equivalent nitrogen atoms in each compound between 0.7MHz and 4MHz. Carr-Purcell based multi-pulse sequences were used to accumulate quadrupole echo signals before the FFT analysis. Assignment of the frequencies to atomic positions was made and the results are analyzed in relation to the molecular chemical bonds and possible H-bonds in the crystal structures. Comparison was made to the previously examined and published NQR spectrum of 1H-tetrazole.