Antioxidant Properties of Lapachol and Its Derivatives and Their Ability to Chelate Iron (II) Cation: DFT and QTAIM Studies

Abstract

The elucidation of the complexation of lapachol and its derivatives to Fe2+ cation has been done using the density functional theory (DFT). This complexation has been limited to bidentate and tridentate to Fe2+ cation. Geometry optimizations have been implemented in gas and solution phase (water, acetonitrile, chlorobenzene, benzene, and toluene) for ligands at B3LYP/6-311++G (d,p) level of theory using B3LYP/6-31+G(d,p) optimized data as starting point. But, the geometrical optimizations in solution phase of the 22 complexes analyzed of lapachol and its derivatives to Fe2+ cation were restricted to acetonitrile and benzene. The complexation energy and the metal ion affinity (MIA) have also been calculated using the B3LYP method. The results obtained indicated a proportionality between the MIA values and the retained charge on Fe2+ cation for k2-(O1,O2) modes. But, an inverse proportionality has been yielded between these two parameters for k3-(O2, C=C) tridentate modes. For k3-(O3,C=C) tridentate mode coordination, the higher stability has been obtained. In this latter tridentate coordination in gas phase, the topological analysis of complexes exhibits the fact that the electron density is concentrated between the O3 oxygen atom of the ligand attached to Fe2+ and this metal cation. Moreover, the hydrogen bond strength calculated for isolated ligands (situated between 23.92 and 30.15 kJ/mol) is in the range of normal HBs. Collectively, all the complexation processes have shown to be highly exothermic. Our results have also shown that the electron extraction from Fe2+...Lai complexes is more difficult compared to that from free ligands.

Determination of Physicochemical Parameters and Levels of Heavy Metals in Food Waste Water with Environmental Effects

“…Determination of heavy metal concentration was performed analytically with the digital UV-spectrophotometer [7]. e collected samples of waste water can be maintained without harming samples biodegradation characteristic and are investigated in [8][9][10][11]. All the reagents used for the analysis were of analytical grade and obtained from Merck and Qualigens brand.…”

Food’s Waste Water Biosolid Assessment against Toxic Element Absorbability of Food’s Cropping Soil Plant by Dominance Theory

“…Various tests are conducted to assess the quantity of organic matters such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), and total organic carbon (TOC) involved in land waste water BSs. The physicochemical parameters, namely, pH, temperature, turbidity, BOD, COD, DO, TOC, conductivity, TDS, TSS, total alkalinity, sulphate, nitrate, phosphate, and heavy metal concentrations (iron, copper, lead, nickel, and zinc) are described by APHA (1992) and Guide Manual (Manivasakam N, 2011), ( [16][17][18], Wanga et al, [19], [20], Djafarou, et al, [21], Florencia et al, [22], Djafarou, et al, [21] Kumar et al, [23]. The authors made effort for the treatment of biosolids or sewage sludge for making it more suitable and feasible BS to be used for a real life application.…”