“…The C–O stretching was observed at 1250-1360 cm -1 range with strong bands. The CH = N groups stretching vibrations appear at 2916.37 cm −1 and the band at 3371.99 cm −1 that does not include hydrogen bonding ν OH [ 31 ]. The sharp peak obtained at 688.05 cm −1 is due to C–H bending.…”