Synthesis, Characterization, Cyclic Voltammetry, and Biological Studies of Co(II), Ni(II), and Cu(II) Complexes of a Tridentate Schiff Base, 1-((E)-(2-Mercaptophenylimino) Methyl) Naphthalen-2-ol (H₂L₁)

Table 5

Thermoanalytical results for CuL₁, CoL₁, and NiL₁ complexes.

Compounds	Step	TGA temperature (°C)	DTA temperature (°C)	Weight loss (%)		Process	Fragment lost
				Found	Calc
CuL1	Single	385	400 (endothermic)	72.11	72.56	Decomposition	C17H13NO (2 moles)
	Residue	>600		23.03	23.34		Cu2S
CoL1	1	220	384 (endothermic)	15.12	15.11	Decomposition	C6H7NS (1 mole) + 3/4H2O
	2	400–556	457 (endothermic)	44.05	44.10	Decomposition	C11H8O2 (2 moles) +C6H7NS (1 mole)
	Residue	>600	—	40,12	41.52		Co2O3; CoS; CO
NiL1	Single	428	430 (endothermic)	68.36	68.55	Decomposition	C17H13NS (2 moles)
	Residue	>600		30.91	30.96		Ni3O2