Coordination modes of multidentate azodye ligand derived from 4,4′‐methylenedianiline towards some transition metal ions: Synthesis, spectral characterization, thermal investigation and biological activity

Abstract

Nine new azodye metal complexes of Mn(II), Co(II), Ni(II), Cu(II), Cr(III), Fe(III), Ru(III), Hf(IV) and Zr(IV) ions have been prepared via the reaction of 5,5′‐((1E,1′E)‐(methylenebis(1,4‐phenylene))bis(diazene‐2,1‐diyl))bis(6‐hydroxy‐2‐thioxo‐2,3‐dihydropyrimidin‐4(5H)‐one) (H4L) with the corresponding metal salts affording sandwich (1 L:1 M), mononuclear (2 L:1 M), binuclear (1 L,2 M) and tetranuclear (1 L,4 M) complexes. Elemental analyses, spectral methods, magnetic moment measurements and thermal studies were utilized to confirm the mode of bonding and geometrical structure for the ligand and its metal complexes. Infrared spectral data show that the H4L ligand chelates with some metal ions in keto–enol–thione or keto–thione manner. It behaves in a neutral/dibasic tetradentate fashion in sandwich and binuclear complexes. Also, it acts as a neutral bidentate moiety in the Cr(III) complex. The spectra reveal that azo group participates in chelation in all complexes. Octahedral geometry was suggested for all chelates but the Cu(II) complex with square planar geometry. The thermal stability and decomposition of the compounds were studied, the data showing that the thermal decomposition ended with metal or metal oxide mixed with carbon as final product. The electron spin resonance spectrum of the Cu(II) complex demonstrates that the free electron is located in the ( dx2−y2) orbital. Measurements of biological activity against human cell lines Hep‐G2 and MCF‐7 reveal that the Cu(II) complex has a higher cytotoxicity in comparison to the free ligand and other metal complexes, with IC50 values of 6.10 and 5.2 μg ml−1, respectively, while the ligand has anti‐tumour activity relative to some of the investigated metal complexes.

Novel lanthanide(III) 4-methylbenzoylhydrazide complexes as precursors for lanthanide oxide nanophotocatalysts

“…The ligand bands at 522 and 446 cm À1 due to g(C]O) and r(NH 2 ) exhibit shis in the ranges of 518 to 528 and 462 to 472 cm À1 upon complexation, which are attributed to y(M-O) and y(M-N), respectively. 17 The absorption bands appearing at around 1380 and 784 cm À1 in the spectra of the investigated complexes are assigned to the ionic nitrate group. 14 The complexes exhibit absorption bands in the regions of 1463 to 1466 cm À1 and 1208 to 1212 cm À1 ; these are not observed in the spectrum of the ligand and can be assigned to y 4 and y 1 , respectively.…”

Synthesis of Some Novel Nanosized Chelates of Anchoring Bisazo Dye 5-[5-(4,6-Dioxo-2-thioxo-hexahydro-pyrimidin-5-ylazo)-naphthalen-1-ylazo]-2-mercapto-1H-pyrimidine-4,6-dione and Their Applications as Antioxidant and Antitumor Agents

“…The appearance of NH protons in a 3:1 ratio with SH proton and the absence of OH protons are indicative of the keto–thione–thiol structure of the ligand . The (C 5 –H) of TBA was detected by two signals at 3.47 and 3.25 ppm . The low integral value of (C 5 –H) protons may be due to some interaction with the solvent .…”

“…22 The (C 5 −H) of TBA was detected by two signals at 3.47 and 3.25 ppm. 23 The low integral value of (C 5 −H) protons may be due to some interaction with the solvent. 24 The broad strong signal at 5.33 ppm was assignable to the solvent of crystallization.…”

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“…On the other hand, 4,4-Methylenedianiline has a wide range of applications, including polyurethane spume, cell strengthening in lubricating oils, azo dye manufacturing, iron corrosion protection, and epoxy resin curing agent [1][2][3][4]. MDA (4,4-Methylenedianiline) has the potential to damage human and animal health because it causes eye irritation and damages the kidneys, liver, and skin; yet, it has been used to create several Schiff bases and azo ligands with important medical and therapeutic properties [5]. Many strains of organisms exhibit resistance to the conventional antimicrobial treatments, and thus microbial resistance is considered to be one of the most important public health challenges in the world.…”