Table 2.

Infrared spectral data for the ligand and complexes

Compounds	Infrared spectral data (cm−1)
	ν (2′-OH)	ν (4′-OH)	ν (OH)acid	ν (C=O)ketone	ν (C=O)acid	ν (N=N)	ν (Co–O)
11	3541	3249	2575	1726	1668	1446	–
12	–	3258	–	1713	1713	1446	528/548
13	–	–	2577	1748	1695	1450	530