Etude vibrationnelle de la 1,2,4-triazole-thione et de ses dérivés N-méthylés. Tautomérie et association Vibrational study of 1,2,4-triazole-thione and its N-methyl derivatives. Tautomerism and association

Molecular geometry and vibrational studies of 3,5-diamino-1,2,4-triazole using quantum chemical calculations and FT-IR and FT-Raman spectroscopies

“…Experimentally, mode 17 is assigned to the intense Raman band at 1020 cm −1 and to the infrared band at 1016 cm −1 . Mode 18 is not observed, as its calculated wave number is lower than values previously found for the triazolic series [13,15,16,19].…”

“…Many authors have studied these compounds and their properties, such as crystal structure [1][2][3][4][5], quantum-chemical calculations on the tautomerism and protonation sites [6][7][8][9][10][11], spectroscopic properties [12][13][14][15][16][17][18][19][20] and thermal decomposition products [21,22]. Guanazole (3,5-diamino-1,2,4-triazole denoted (NH 2 ) 2 TA (Fig.…”

Polymorphism in 4-methyl-1,2,4-triazolethione

“…However, some infrared and Raman bands assigned to intramolecular vibrations shift by about 10 cm 1 : the ring vibrations at 1485 and 1270 cm 1 and the CH component about 880 cm 1 . The stable phase S shows a classical behaviour with only some slight wavenumber shifts (generally 1-3 cm 1 ) and broadening of the bands.…”

“…1(b)]: 881-852 cm 1 (also observed in the Raman spectra) and 786-745 cm 1 , respectively. 1 X-ray structural studies confirmed this structural feature. Those splittings cannot be attributed to tautomeric forms, as in the case of C-substituted 1,2,4-triazoles, 2 because only the thione form, containing an NH group, is compatible with the IR spectra.…”

“…1 In the infrared spectra of crystals obtained by sublimation or by cooling of liquid, or from aqueous or alcoholic solutions, the CH and NH modes show large splittings [ Fig. On the other hand, the CH stretching Raman mode is also split by 41 cm 1 . On the other hand, the CH stretching Raman mode is also split by 41 cm 1 .…”