Characterization of Complexes Synthesized Using Schiff Base Ligands and Their Screening for Toxicity Two Fungal and One Bacterial Species on Rice Pathogens

Table 10

Characteristic IR data for the L4-BFH (bidentate –O, –N) and its participation in complex formation with metal ions.

S. number	Complex	IR cm^−1 (s = sharp; b = broad; d = doublet; w = weak; vw = very weak)
		Coord water	vN–H	vC=O	vC=N^d	M–O, M–N, M–Cl^e
1	BFH-L4^b	—	3240 (s)^a	1650 (s)	1620 (s)	—
2	[Cr(BFH)(H2O)Cl2]2	3550–3450	Absent^c	—	1610 (s), 1590 (s)	830, 570, 400 (s), 300 (vw)
3	[Cr(BFH)2(H2O)Cl]	3550–3450	Absent^c	—	1610 (s) 1590 (s)	840, 575, 395 (s), 300 (vw)
4	[VO(BFH)2(H2O)]	3550–3450 (b)	Absent^c	—	1600–1610 (s)	970 (V=O), 810, 440, 350

Hydrazone moiety; ^bNo shift in symmetric and asymmetric stretching frequencies of furfural ring oxygen at 1020 (s), 895 (s) cm⁻¹ and N–N at 1040 (w) indicates no involvement in complex formation; ^cAbsence of vN–H band suggests enolization of the ligand which is confirmed by disappearance of strong vC=O band; ^dShift indicates participation of –N of azomethine group in coordination; ^eNakamoto [91, 100] and Selbin [94].