Mangesh P. Gharpure

Chelate polymer compounds with bis(bidentate) ligand: synthesis, spectral, morphological and thermal degradation studies

Four divalent transition chelate polymer compounds (1–4) were synthesised by condensation of ibpmpc (isophthaoyl bis(paramethoxyphenylcarbamide)) with metal acetate in a dimethylformamide medium. The synthesised polymer compounds 1–4 were characterised by elemental analyses, FT-IR, diffuse reflectance, magnetic moment measurements and thermal studies. Each metal ion is coordinated through an oxygen atom of the carboxylate group and a nitrogen atom of the amide group of ligand and two aqua ligands by the coordinated bond which formed a six-member heterocyclic ring and significantly formed octahedral geometry for 1–3, whereas distorted octahedral geometry for 4. The thermal properties were studied by TG/DTG/DTA analyses. It was found that the thermal stabilities of polymer compounds follow the order: 4 > 3 > 1 > 2 Also, their physical properties including solubility, colour and melting point were studied, and the result showed insolubility in common organic solvents. Moreover, SEM and XRD studies were carri...

Synthesis of new series of 3-hydroxy/acetoxy-2-phenyl-4H-chromen-4-ones and their biological importance

Abstract3-Hydroxy-2-aryl/heteroaryl-4H-chromones 4(a–n) were synthesized from appropriate chalcones 3(a–n) and acetylated to afford the corresponding acetoxy derivatives 5(a–n). All compounds were evaluated for antimicrobial activity against Staphylococus aureus, Bacillus subtillis, Escherichia coli and Pseudomonas aeruginosa as well as fungi e.g., Candida albicans and Aspergius niger. Inhibition caused by hydroxy flavones was relatively low, whereas that of their acetoxy ester analogues was substantially high. Structure of 6-chloro-2-(furan-2-yl)-4-oxo-4H-chromen-3-yl acetate (5j) was also supported by means of single crystal X-ray diffraction. Graphical AbstractAn effective microwave-assisted synthesis of 3-acetoxy-2-aryl/heteroaryl-4Hchromones 5a-n has been achieved through a series of reactions starting from phenols. These compounds have been screened against gram (+) ve and (-) ve bacteria. The acetoxy flavones were biologically more active than the corresponding hydroxyflavones.

Synthesis, characterization and thermal properties of phthaloyl bis (paramethoxyphenylcarbamide) chelate polymers of divalent transition metals

Seven novel divalent transition metal chelate polymer complexes commonly known as coordination polymers or chelate polymers or coordination complexes such as [Mn (pbpmpc) (H2O)2]n (1), {[Co(pbpmpc) (H2O)2] 4H2O}n (2), {[Ni (pbpmpc) (H2O)2] 2H2O}n (3), {[Cu (pbpmpc) (H2O)2] 1H2O}n (4), {[Zn (pbpmpc)]}n (5), {[Cd (pbpmpc)]}n (6) and {[Hg (pbpmpc)] 1H2O}n (7) were synthesized under an aprotic solvent with phthaloyl bis (paramethoxyphenylcarbamide) (pbpmpc) as a polydentate ligand. The authenticities of these chelate polymers were characterized by elemental analyses: diffuse reflectance spectroscopy, magnetic susceptibility measurements, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermal analyses and scanning electron microscope (SEM) techniques. SEM and XRD investigations significantly revealed a distinct morphology behavior of ligand and chelate polymers. The infrared spectroscopy supports the interaction of nitrogen and oxygen atoms of a polydentate ligand with a metal ion, while diffuse reflectance study is a powerful technique that suggests an octahedral geometry for all the chelate polymers except zinc, cadmium and mercury ions, which were further supported by other instrumental techniques. The decomposition steps and thermal stabilities of these chelate polymers were studied by thermal analysis techniques. The thermal stabilities of chelate polymers were identified on the basis of release of coordinated water and decomposition of backbone structure (ligand).

Oxovanadium (IV) complexes of 2-aryl/heteroaryl-3-hydroxy-4H-chromones: synthesis, spectral and thermal degradation studies

The clinically active functionalized flavonols (2-aryl/heteroaryl-3-hydroxy-4H-chromones) (4a-l) have been synthesized from Algar–Flynn–Oyamada transformation of chalcones (1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-ones). Their oxovanadium metal complexes (5a-l) have been prepared and characterized by physical, spectral, thermal and analytical data. The functionalized flavonol acts as bidentate ligand and coordinates with vanadium metal atom through hydroxyl and carbonyl groups. The complexes have general formula [MOL2], where M = vanadium, O = oxygen and L = ligand. The chelation process reduces the polarity of metal ion by coordinating with ligands, which increase the lipophilic nature of the metals. This lipophilic nature of the metal enhanced its penetration through the lipoid layer of cell membrane of the micro-organism. This constitutes a new group of compounds that can be used as potential metal-derived drugs.

Oxovanadium (IV) complexes with O-O donors ligands: efficient synthesis, spectral characterization, antimicrobial activity and thermal degradation

The clinically active functionalized flavonols (2-aryl/heteroaryl-3-acetoxy-4H-chromones) 5(a-g) were synthesized from Algar–Flynn–Oyamada transformation of chalcones (1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-ones) 4(a-g). Furthermore, oxovanadium metal complexes 6(a-g) of ligands 5(a-g) were synthesized and characterized by physical, Fourier transform infrared (FT-IR) spectroscopy, 1H NMR, mass, UV-reflectance spectroscopy, magnetic moment susceptibility, thermal and analytical data. The functionalized flavonol acts as bidentate chelating ligand and coordinate with vanadium metal atom through hydroxyl and carbonyl groups. The complexes have general formula [MOL2] where M = vanadium, O = oxygen and L = ligand. The chelation process reduces the polarity of metal ion by coordinating with ligands, which increase the lipophilic nature of the metals. This lipophilic nature of the metal enhanced its penetration through the lipoid layer of cell membrane of the micro-organism. This constitutes a new group of compounds that can be used as potential metal derived drugs. Therefore, the synthesized compounds were screen for their antifungal activity against A. niger and C. albicans using the cup plate diffusion method, however antibacterial activities screen against pathogenic bacteria such as E. coli, S. aureus, B. subtilis and P. aeruginosa.

Facile synthesis, thermal degradation and effective antimicrobial activities of Cu (II) complexes with bis [3-acetoxy-2-aryl/heteroaryl-4H-chromone]

AbstractThis article reports the synthesis of bis [3-acetoxy-2-aryl/heteroaryl-4H-chromone] Cu (II) complexes 6(a–g) in 1:2 stoichiometry ratio of copper acetate and 3-acetoxy-2-aryl/heteroaryl-4H-chromone. While chelating ligands, active functionalized 3-acetoxyflavones (2-aryl/heteroaryl-3-acetoxy-4H-chromones) 5(a–g) are synthesized by Algar–Flynn–Oyamada transformation of chalcones (1-(2-hydroxyphenyl)-3-phenylprop-2-en-1-ones) 4(a–g). The synthesized copper complexes are characterized by the standard techniques such as physical Fourier transform infrared spectroscopy (FT-IR), UV-reflectance spectroscopy, magnetic susceptibility and thermal analysis. Furthermore, antimicrobial activities are investigated using the standard methods. The antifungal activity was tested against Rhizoctonia solani and Candida tropicals, while antibacterial activity was screened against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa.