“…The results indicate that the nitrogen atom of the −CH=N− group in L ligands was coordinated. [ 37–39 ] The C−O stretching vibrations of the free HL ligands at 1245 and 1232 cm −1 for free HL 1 and HL 2 , respectively, red‐shifted to 1214, 1214, 1207, and 1226 cm −1 for 1 – 4 , respectively, suggesting its participation in chelation. [ 35,40 ] The bands at 3130, 3124, 3111, 3143, 3117, and 3130 cm −1 for HL 1 , HL 2 , 1 – 4 , respectively, are attributed to the weak C−H stretching vibration of the benzene ring, while those at 868, 868, 849, 855, 843, and 855 cm −1 for HL 1 , HL 2 , 1 – 4 , respectively, are attributed to the C−X (X = Cl or Br) stretching vibration.…”