Synthesis and characterization of 4,5-dicyano-2H-1,2,3-triazole and its sodium, ammonium, and guanidinium salts.

ABSTRACT

In this contribution, the synthesis and structural characterization of the 4,5-dicyano-1,2,3-triazolate anion in its sodium, ammonium, guanidinium, aminoguanidinium, diaminoguanidinium, and triaminoguanidinium salts is reported. The synthesis of 4,5-dicyano-2H-triazole (1) was repeated as described in the literature (Johansson, P. et al. Solid State Ionics 2003, 156, 129) and spectroscopically characterized using (1)H, (13)C, and (15)N NMR, IR, and Raman spectroscopy, as well as differential scanning calorimetry (DSC) and mass spectrometry (DEI+). The molecular structure was determined for the first time using X-ray diffraction (1 monoclinic, P2(1)/c, a = 6.0162(6) A, b = 11.2171(10) A, c = 7.5625(7) A, beta = 94.214(8) degrees, V = 508.97(8) A(3), Z = 4). Compound 1 was deprotonated using Na(2)CO(3) to form the corresponding sodium salt of the 4,5-dicyano-1,2,3-triazolate anion (2) as a monohydrate. This compound was also characterized using (13)C, (14)N, (15)N NMR, IR, and Raman spectroscopy, as well as single crystal X-ray diffraction (2 monoclinic, P2(1)/c, a = 3.6767(6) A, b = 20.469(4) A, c = 9.6223(13) A, beta = 97.355(13) degrees, V = 718.2(2) A(3), Z = 4). Reaction of 2 with AgNO(3) yielded silver 4,5-dicyano-1,2,3-triazolate (3) which was characterized using IR and Raman spectroscopy, as well as DSC, and was used to prepare the ammonium (4), guanidinium (5), aminoguanidinium (6), diaminoguanidinium (7), and triaminoguanidinium (8) salts of the 4,5-dicyano-1,2,3-triazolate anion in a metathetical reaction from the corresponding ammonium and guanidinium halides. All new compounds (4-8) were spectroscopically characterized ((1)H and (13)C NMR, IR, Raman), the stabilities investigated using DSC, the mass spectra obtained using the FAB+ and FAB- methods and the solid state structures determined using single crystal X-ray diffraction (4) orthorhombic, Pnma, a = 6.5646(13) A, b = 7.5707(16) A, c = 13.303(3) A, V = 661.1(2) A(3), Z = 4; (5) monoclinic, Cc, a = 12.6000(11) A, b = 17.1138(15) A, c = 12.0952(9) A, beta = 106.098(7) degrees, V = 2505.9(4) A(3), Z = 12; (6) monoclinic, Pa, a = 7.0921(9) A, b = 7.2893(9) A, c = 8.8671(11) A, beta = 105.141(11) degrees, V = 442.48(10) A(3), Z = 2; (7) monoclinic, P2(1), a = 3.7727(4) A, b = 15.6832(17) A, c = 8.3416(10) A, beta = 101.797(10) degrees, V = 483.13(9) A(3), Z = 2; (8) monoclinic, C2/c, a = 14.0789(14) A, b = 11.5790(11) A, c = 13.5840(14) A, beta = 115.239(10) degrees, V = 2003.1(3) A(3), Z = 8. The impact and friction sensitivities of compounds 4-8 were investigated using drop hammer and friction apparatus methods, and all compounds were found to be neither impact (> 30 J) nor friction sensitive (> 360 N). The detonation parameters of compounds 5- 8 were computed using the EXPLO5 code.