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

Table 18

Predicted molecular formula, structure, and geometry from electronic spectra and magnetic moment data for Ni(II) complexes with L1–L3 ligands.

S. number	Molecular formula-electronic spectra^b bands, transitions^a,; predicted structure (a rough M–L sketch given), and geometry^a				BM
1	[Ni(BHFH)H2O]; Square-planar complex with –OH2 and L1 with –O, –O, and –N coordination on the equatorial plane	26,130; 18,100	Charge-transfer band d-pi* transition; 1A1g · 1A2g; Square-planar geometry		Dia
2	[Ni(BHFH)2]; Regular Oh complex with two L1 with –O, –O, and –N coordination	26,300; 15,000; 9,520 (w)	3A2g-3T1g (P); 3A2g-3T1g (G); 3A2g-3T2g; Regular Oh geometry		3.24
3	[Ni(BHEH)2]; Regular Oh complex with two L1 with –O, –O, and –N coordination	26,670 (s); 20,000; 13,100; 8,200 (w)	Strong charge-transfer band-d-pi* transition; 3A2g-3T1g (P); 3A2g-2T1g, 3T1g (F); 3A2g-3T2g; Regular Oh geometry		2.91
4	[Ni(HAEP)2]; Distorted square-planar complex with S bridges and two L3 with –O, –N, –S (used in bridging) coordination on the equatorial plane	27,030; 16,600	Charge-transfer band d-pi* transition; 1A1g-1A2g; Diamagnetic tetragonal or square planar complex with high intensity band in 14000–18000 cm^−1		Dia; M–M

Holm et al. [77]; Shaw and Dudek [106]; Drago [74]; ^bRecorded for solid compounds (mull-diffuse reflectance) at room temperature—Figure 7.