Thermal studies and mass loss inhibition for some new mixed amino acid metal complexes with their applications

Abstract

A thermal gravimetric analysis was studied for the new metal mixed-ligand complexes of copper(II), nickel(II), cobalt(II), and zinc(II) metals formed with glutamic acid as a primary ligand and nitrilotriacetic acid (H 3 NTA) as a secondary ligand which have been characterized by their elemental analysis, magneto-chemical measurements, Fourier transform infrared (FTIR), UV-Vis spectrophotometer, thermal gravimetric analysis, and mass spectroscopy studies. Glutamic acid in these complexes acts as a bidentate ligand, coordinating through the one nitrogen of the amino group and one oxygen of the carboxylate group, whereas nitrilotriacetic acid shows a tridentate nature, and the coordination occurs through two carboxylate oxygen and one nitrogen of the amino group. Water molecules satisfy the remaining coordination positions. The complexes have been suggested to show geometry of an octahedral symmetry. The results were indicated that the mixed complexes were isolated in 1:1:1 molar ratio (metal-glutamic-HNTA), and the molecular structures were suggested to be [M(glutamic)(HNTA) (H 2 O)]Á(2-1.5)H 2 O. The antimicrobial activities of our prepared complexes evaluated against Escherichia coli, Staphylococcus aureus, Candida albicans, and Aspergillus flavus (isolates from Micro-analytical Center, Faculty of Science, Cairo University) were investigated. Also, our prepared complexes were evaluated for their in vitro anticancer activity against hepatocellular carcinoma. In addition, the mass loss inhibition effects for copper and aluminum metal plates by our prepared complexes in 1 M HCl were studied.

Transition Metal Complexes of Mixed Bioligands: Synthesis, Characterization, DFT Modeling, and Applications

“…en, 10D q � 10637.253 cm −1 is compared to the value of 10935 cm −1 obtained by the first method and both values confirm octahedral structure [34]. e magnetic moment of the nickel complex was 3.1 which also confirmed octahedral structure [16].…”

“…e mass spectra of the four complexes were recorded and provided good evidence and confirmation of the molecular weight of these complexes (molecular ion peaks (MIPs) are detected under severe experimental conditions [16], which results in of splitting of crystalline water) ( Figure 2S shows the mass spectrum of Zn(II) complex as example). Figure 4 shows the theoretical and experimental UV-Vis spectra of Co(II) and Cu(II) as examples.…”

“…where R blank � corrosion rates in the absence of inhibitor and R inh � corrosion rates in the presence of inhibitor [16]. Table 8 shows the calculated corrosion rates and inhibition efficiencies of aluminum specimens in aqueous solution of 1M HCl as the corrosive medium in absence and presence of mixed ligands and their ternary metal complexes at different temperatures (293 -313) K for 7 hours of each concentration.…”

“…It is known that amino acids act as an eco-friendly inhibitor for several metals as copper, aluminum, steel, and nickel. L-arginine and its zinc complex are used as nontoxic and low-cost corrosion inhibitors for carbon steel [14][15][16].…”

“…us, we will investigate calcinating the complexes under investigations to check the possibility of obtaining metal nano-oxides in a facile way for possible application as photocatalysts. [M(II)(Glu)(Arg)] complexes were synthesized following the method used in [16]. Refluxing equal-molar amounts of M(II)carbonate (1 mmol, powder) and water-soluble glutamic acid (1 mmol), L-arginine (1 mmol) in ∼100 ml bidistilled water at about 80-363 K for 2-3 days gives dense precipitate upon scratching.…”