## 2 Results and Discussion
### Synthesis of Compounds
#### 2.1.2 Synthesis and Characterization of Bis-Triazoles 1**a-d**  
Synthesis of 4_H_-4-amino-5-mercapto-3-(4_H_-4-amino-5-mercapto-1,2,4-triazol-3-yl)-1,2,4-triazole (1**a**) and 1,n-bis-(4_H_-4-amino-5-mercapto-1,2,4-triazol-3-yl)alkanes (1**b-d**) started from dihydrazides (3**a-d**), as presented in Scheme 2. Following the protocol presented in Section 3.2.2, the four triazoles were obtained with variable yields (12-60%), and characterized by melting point, elemental analysis, FTIR, 1H-NMR and 13C-NMR spectroscopy (Table 2). \begin{table}
\begin{tabular}{c c c c} \hline \hline  & \multicolumn{4}{c}{**Characterization of Compound**} \\ \cline{2-4}
**Structure of Dihydrazide** & \begin{tabular}{c} **Molecular Formula,** \\ **Molar Mass, Aspect and** \\ **Synthesis Yield** \\ \end{tabular} & \begin{tabular}{c} **Melting Point (\({}^{\circ}\)C)** \\ **Measured/Literature** \\ \end{tabular} & \begin{tabular}{c} **FTIR Bands** \\ **(KBr, cm\({}^{-1}\)):** \\ \end{tabular} \\ \hline CONHNH\({}_{2}\) & \begin{tabular}{c} C\({}_{2}\)H\({}_{6}\)N\({}_{4}\)O\({}_{2}\) \\ \(\mathrm{CONHNH}_{2}\) \\ \end{tabular} & \begin{tabular}{c} \\ M = 118 g\(\cdot\)mol\({}^{-1}\) \\ \end{tabular} & 190–194/ & 3286, 3195, 1650, \\ Oxalyl dihydrazide & \begin{tabular}{c} White powder \\ yield \(\eta\) = 82\% \\ \end{tabular} & 242–244 [48] & 1612, 1504, 748 \\ \hline CONHNH\({}_{2}\) & \begin{tabular}{c} C\({}_{3}\)H\({}_{8}\)N\({}_{4}\)O\({}_{2}\) \\ \(\mathrm{CONHNH}_{2}\) \\ \end{tabular} & \begin{tabular}{c} \\ M = 132 g\(\cdot\)mol\({}^{-1}\) \\ \end{tabular} & 152–157/ & 3330, 3035, 1626; \\ CONHNH\({}_{2}\) & \begin{tabular}{c} White powder \\ yield \(\eta\) = 79\% \\ \end{tabular} & 152–154 [49] & 1076; 1122; 1504 \\ Malonic dihydrazide (Malonic acid dihydrazide) (3**b**) & & & \\ \hline CONHNH\({}_{2}\) & \begin{tabular}{c} \\ C\({}_{4}\)H\({}_{10}\)N\({}_{4}\)O\({}_{2}\) \\ \(\mathrm{CONHNH}_{2}\) \\ \end{tabular} & \begin{tabular}{c} \\ M = 146 g\(\cdot\)mol\({}^{-1}\) \\ \end{tabular} & 166–171/ & 3289; 3195; 1540; \\ Subcinci dihydrazide (Succinic acid dihydrazide) (3**c**) & & 170–171 [50] & 1509 \\ \hline CONHNH\({}_{2}\) & \
\begin{tabular}{c} \\ C\({}_{6}\)H\({}_{14}\)N\({}_{4}\)O\({}_{2}\) \\ \(\mathrm{CONHNH}_{2}\) \\ \end{tabular} &
\begin{tabular}{c} \\ M = 174 g\(\cdot\)mol\({}^{-1}\) \\ \end{tabular} & 174–181/ & 3200, 3311, 3181, \\ Subcinci dihydrazide (Succinic acid dihydrazide) (3**c**) & & 180–182 [51] & 3047, 2925; 1636, \\ Subcinci dihydrazide (Adipic acid dihydrazide) (3**d**) & & 1536 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Structure and characterization of the obtained dihydrazides of oxalic, malonic, succinic and adipic acids. The analysis of the FTIR spectra of 4-amino-5-mercapto-3-(4\(H\)-4-amino-5-mercapto-1,2,4-triazol-3-yl)-1,2,4-triazole (**1a**) reveals the appearance of several characteristic bands [40]. For the primary amino group, the N-H stretching vibration is revealed by the band with a maximum at 3330 cm\({}^{-1}\). The stretching vibrations of the aromatic C-H bond at 3044 cm\({}^{-1}\), as well as the stretching vibrations of the double C=N bonds, can be identified in the spectrum at 1590 cm\({}^{-1}\). The existence of the compound in the thione tautomeric form (C=S) is confirmed by the band that appears at 1251 cm\({}^{-1}\)[40; 54]. The presence of the primary amino groups (-NH\({}_{2}\)) in the structure of 1,1-bis-(4\(H\)-4-amino-5-mercapto-1,2,4-triazol-3-yl)methane (**1b**) is indicated by the presence of the bands at 3291 and 3242 cm\({}^{-1}\). The stretching vibrations of the aromatic C-H bond are observed at 3076 and 3026 cm\({}^{-1}\), as well as the symmetric and asymmetric vibrations corresponding to the CH\({}_{2}\) group at 2923 and 2807 cm\({}^{-1}\). The stretching vibrations of the C=N bonds are represented by the band observed at 1614, while the C=S vibration is represented by a band at 1235 cm\({}^{-1}\).