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

Table 17

Predicted molecular formula, structure, and geometry from electronic spectra and magnetic moment data for Co(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	[Co(BHFH)(H2O)Cl]2; Distorted Oh complex with Cl bridges, two −OH2, and two L1 with –O, –O, and –N coordination on the equatorial plane	31,250; 20,000; 18,520; 15,400	4T1g (F)-4T1g (P); 4T1g (F)-4T2g (F) broad bands; Multiple bands in admixture with spin-forbidden transition to doublet state		4.58; M–M
2	[Co(BHEH)2]; Oh complex with two L2 with –O, –O, and –N coordination on the equatorial plane	19,750; 18,450; 15,700; 8,430			3.92
3	[Co(HAEP)(H2O)2]2; Distorted Oh complex with S bridges, two –OH2, two –Cl, and two L3 with –O, –N, and–S (used in bridging) coordination on the equatorial plane	27,030; 17,700; 15,630; 8,330			4.53; M–M

Lever [73]; the asymmetric visible band is typical of Oh Co(II) complexes and the shoulder on the high energy side being assigned to spin-forbidden transitions, Drago [74]; ^bRecorded for solid compounds (mull-diffuse reflectance) at room temperature—Figure 6.