**3.3 Infrared spectrum**

The infrared spectrum of the ligand showed broad bands at 3650, 3665, 3620 and 3180 cm−1 are assigned to the <sup>υ</sup> (OH)/H2O groups. The two bands located at 1705 and 1690 cm−1 are assigned to the two (C=O) groups, whereas the other two bands observed at 1630 and 1622 cm−1 are attributed to <sup>υ</sup> (C=N). Presence of the two (C-OH) groups was further supported by the two vibrational bands observed at 1318, 1272, whereas the presence (N-N) group was supported by the vibrational band observed at 1115 cm−1. The IR spectrum showed a band at 1569 cm−1 which is related to <sup>υ</sup> (C=C)Ar. [54].
