Synthesis, Spectroscopic Characterization, and Biological Evaluation Studies of 5-Bromo-3-(((hydroxy-2-methylquinolin-7-yl)methylene)hydrazono)indolin-2-one and Its Metal (II) Complexes

Table 3

IR spectral bands of the ligand (BHMQMHI) and its metal complexes (cm⁻¹).

Tentative assignments	L	Co(II) complex	Ni(II) complex	Cu(II) complex	Zn(II) complex	Cd(II) complex	Hg(II) complex
Hydrogen bonded OH group	3364	—	—	—	—	—	—
Indole ring NH	3203	3203	3203	3203	3023	3203	3203
ν(C=O) ring	1696	1685	1686	1679	1647	1672	1667
ν(C=N) ring	1603	1603	1603	1603	1603	1603	1603
ν(C=N) aldimine	1583	1565	1525	1530	1533	1505	1549
ν(C–O)	1289	1300	1307	1306	1314	1344	1360
ν(N–N)	991	1067	1082	1035	1099	1059	1033
ν(M–N)	—	479	496	468	477	489	489
ν(M–O)	—	533	578	500	500	523	598
ν(M–Cl)	—	—	—	—	344	358	366