Shadma Parveen

Synthesis, characterization and anti-microbial studies of a newly developed polymeric Schiff base and its metal-polychelates

A new polymeric Schiff base containing formaldehyde and piperazine moieties has been synthesized by condensation of salicylaldimine, formaldehyde and piperazine in alkaline medium; its metal polychelates have also been synthesized with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) acetate. The synthesized Schiff base and its metal polychelates were characterized by elemental, spectral (IR, 1H NMR, UV-visible) and thermogravimetric analysis (TGA). Electronic spectra and magnetic moments indicate that Mn(II), Co(II) and Ni(II) polychelates show octahedral geometry, while Cu(II) and Zn(II) polychelates show square planar and tetrahedral geometry, respectively. All compounds show excellent anti-bacterial as well as anti-fungal activity against three bacteria and two fungi. The anti-microbial activities were determined by using agar well diffusion method, with 50 µg mL−1 and 100 µg mL−1 concentration of each compound tested against the microbes.

Synthesis, characterization, and biocide properties of semicarbazide-formaldehyde resin and its polymer metal complexes.

Semicarbazide-formaldehyde resin (SFRs) was prepared by the condensation of semicarbazide with formaldehyde in an acidic medium and its polymer metal complexes were prepared with transition metal ions. All the synthesized polymers were characterized by elemental analysis, FTIR, (1)H NMR, (13)C NMR, electronic spectroscopy, magnetic moment measurement and thermogravimetric analyses. The percentage of metal in all the polymer metal complexes was found to be consistent with 2:1 (resin: metal) stoichiometry. The magnetic susceptibility measurement and electronic spectra of all the polymer metal complexes confirmed the geometry of the complexes. All the synthesized polymeric compounds have been screened in vitro against Bacillus subtilis, Staphylococcus aureus (Gram-positive) and Escherichia coli, Salmonella typhi (Gram-negative) using shaking flask method. The entire polymer metal complexes showed excellent anti-bacterial activity and low toxicity when compared with their parental polymeric resin. The anti-bacterial activity and toxicity of the entire synthesized compound is significant and they can be used as antimicrobial as well as anticancer agents for mammals in future.

Antimicrobial polyesters containing Schiff-base metal complexes

Antimicrobial polyesters containing Schiff-base metal complexes (PSB) were prepared by polycondensation of adipoyl chloride with chelated Schiff-base diol {bis-(2-hydroxy-5-methylol-benzaldehyde)ethylenediamine}. All the metal chelated polyesters were characterized by elemental analysis, UV–Visible, FTIR, 13C and 1H NMR spectra and thermogravimetric analysis. The analytical data of the polyesters agreed with 1 : 1 molar ratio (metal chelated diols to adipoyl chloride). The geometry of the chelated polyesters was confirmed by magnetic susceptibility measurements and UV–Visible spectroscopy. The thermal behaviors of these chelated polyesters were studied by TGA (Thermogravimetric analyzer) in a nitrogen atmosphere up to 800°C. The TGA results revealed that the Cu(II) chelated polyester has better heat resistant properties than the other polyesters. The antimicrobial properties of these polyesters were investigated with agar diffusion methods against selected microorganisms Bacillus subtelillis, Bacillus megaterium, Streptococcus aureus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, Shigella boydii and for antifungal activity against Candida albicans, Trichophyton longifusus, Aspergillus flavus, Aspergillus niger, Fusarium solani, Microsporum canis, Puccinia graminis. The antimicrobial activity of these polyesters was higher than standard drugs Kanamycin and Miconazol.

Antimicrobial agents: synthesis, spectral, thermal, and biological aspects of a polymeric Schiff base and its polymer metal(II) complexes

Some new coordination polymers of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) obtained by the interaction of metal acetates with polymeric Schiff base containing formaldehyde and piperazine have been investigated. Structural and spectroscopic properties have been studied by elemental, spectral (FT-IR, 1H-NMR, and UV-Vis), and thermogravimetric analysis. UV-Vis spectra and magnetic moments indicate that Mn(II), Co(II), and Ni(II) polymer metal complexes are octahedral, while Cu(II) and Zn(II) polymer metal complexes are square planar and tetrahedral, respectively. All compounds were screened for their antimicrobial activities against Escherichia coli, Bacillus subtillis, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Candida albicans, Agelastes niger, and Microsporum canis using the Agar well diffusion method with 100 µg mL−1 of each compound.

Antimicrobial Polychelates: Synthesis and Characterization of Transition Metal Chelated Barbituric Acid–Formaldehyde Resin

A monomeric Schiff base was prepared by the condensation reaction of salicylaldehyde and semicarbazide, which further react with formaldehyde and barbituric acid-formed polymeric Schiff base. Its metal polychelates were then formed with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II). All the synthesized compounds were characterized by elemental analysis, magnetic moment, FTIR, 1HNMR, and electronic spectroscopies. The elemental analysis data show the formation of 1:1 [M: L] metal polychelates. Thermogravimetric analysis was carried out to find the thermal behavior of all the synthesized polymeric compounds and thermal data revealed that all the metal polychelates are more thermally stable than their parent polymeric Schiff base. All the synthesized polymeric compounds were screened for antimicrobial activity against some clinically important microorganisms, such as Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, Staphylococcus typhi, Candida albicans, Microsporum canis, and Aspergillus niger. In vitro antimicrobial activity was determined by the Agar Well Diffusion method and the result shows that all the metal polychelates exhibited better antimicrobial activity than their parent polymeric Schiff base.

Synthesis and characterization of metal-incorporated aniline formaldehyde resin modified by amino acid for antimicrobial applications

Advances in metal incorporated resins are now an active field of research. To develop resin having better antimicrobial and thermal activity, a series of metal-chelated resins have been synthesized by the condensation of (4-aminobenzene-1,3-diyl)dimethanol with 2,6-diaminohexanoic acid in alkaline medium and then this polymeric ligand further reacts with transition metal ions forming various coordination polymers. (4-Aminobenzene-1,3-diyl)dimethanol was initially prepared by the reaction of aniline and formaldehyde in 1 : 2 molar ratio in alkaline medium. The analytical data reveal that the polymer metal complexes of Mn(II), Co(II), and Ni(II) are coordinated with two water molecules, which are further supported by FTIR spectra and TGA data. Comparative analyses of the polymer metal complexes in thermal curves show better thermal stability than the polymeric ligand. Since these resins are relatively stable at high temperatures, they can be used for medical and biomaterial applications requiring thermal sterilization, solvent-resist coating materials because of their insoluble nature, and antifouling coating materials owing to antimicrobial activity in fields such as life-saving medical devices and the bottoms of ships.

Coordination Polymer: Synthesis, Spectral Characterization and Thermal Behaviour of Starch-Urea Based Biodegradable Polymer and Its Polymer Metal Complexes

A starch-urea-based biodegradable coordination polymer modified by transition metal Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) was prepared by polycondensation of starch and urea. All the synthesized polymeric compounds were characterized by Fourier transform-infrared spectroscopy (FT-IR), 1H-NMR spectroscopy, 13C-NMR spectroscopy, UV-visible spectra, magnetic moment measurements, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). The results of electronic spectra and magnetic moment measurements indicate that Mn(II), Co(II), and Ni(II) complexes show octahedral geometry, while Cu(II) and Zn(II) complexes show square planar and tetrahedral geometry, respectively. The thermogravimetric analysis revealed that all the polymeric metal complexes are more thermally stable than the parental ligand. In addition, biodegradable studies of all the polymeric compounds were also carried out through ASTM standards of biodegradable polymers by CO2 evolution method.

New biocidal metal complexes of bisphenol-A formaldehyde polymer containing piperazine

The polymeric ligand (BFP) was synthesized by condensation of bisphenol-A, formaldehyde, and piperazine in alkaline medium at 70–80°C. The polymer–metal complexes were synthesized by the reaction of BFP with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) acetates in 1 : 0.5 (ligand : metal) molar ratio. All the synthesized polymers were characterized by elemental, spectral (infrared, 1H-NMR, and UV-Vis), magnetic moment measurements, and thermal (TGA) analysis. The ligand-field and nephelauxetic parameters have been determined from UV-Vis spectra using ligand-field theory. Elemental analyses indicate the association of water with metal for Mn(II), Co(II), and Ni(II), which is also supported by TGA. The antimicrobial activities of the synthesized polymers were studied by agar well diffusion methods against Bacillus subtilis, Bacillus megaterium, Staphylococcus aureus, Escherichia coli, Salmonella typhi, Pseudomonas aeruginosa, and Shigella boydii. The antimicrobial activity and thermal stability of Cu(II)–polymer were higher than the other polymer–metal complexes due to the higher stability constant of Cu(II).

Preparation, spectral and biological investigation of formaldehyde-based ligand containing piperazine moiety and its various polymer metal complexes.

A novel tetradentate salicylic acid-formaldehyde ligand containing piperazine moiety (SFP) was synthesized by condensation of salicylic acid, formaldehyde and piperazine in presence of base catalyst, which was subjected for the preparation of coordination polymers with metal ions like manganese(II), cobalt(II), copper(II), nickel(II) and zinc(II). All the synthesized polymeric compounds were characterized by elemental analysis, IR, (1)H NMR and electronic spectral studies. The thermal stability was determined by thermogravimetric analysis and thermal data revealed that all the polymer metal complexes show good thermal stability than their parent ligand. Electronic spectral data and magnetic moment values revealed that polymer metal complexes of Mn(II), Co(II) and Ni(II) show an octahedral geometry while Cu(II) and Zn(II) show distorted octahedral and tetrahedral geometry respectively. The antimicrobial screening of the ligand and coordination polymers was done by using Agar well diffusion method against various bacteria and fungi. It was evident from the data that antibacterial and antifungal activity increased on chelation and all the polymer metal complexes show excellent antimicrobial activity than their parent ligand.

Synthesis, characterization and anti-microbial activity of poly(ethylene oxamide- N,N ′-disuccinate) and its polymer metal complexes

Poly(ethylene oxamide-N,N′-disuccinate), abbreviated as (PEODS), has been synthesized by condensation of oxamide-N,N′-disuccinic acid and 1,2-ethylene glycol. Coordination polymers were synthesized by the reaction of (PEODS) with hydrated acetates of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II). The resulting polyester-metal complexes were characterized by elemental analysis, UV-Visible, FT-IR, 1H-NMR, ESR spectroscopy and magnetic susceptibilities. Thermal behavior of all the synthesized compounds revealed that polymer metal complexes are more stable than the polymeric ligand. In addition all the synthesized polymers were screened for anti-bacterial activity against B. subtelillisr, B. megaterium, S. aureus, E. coli, S. typhi, P. aeruginosa, S. boydii and for antifungal activity against C. albicans, T. species, A. flavus, A. niger, F. species, M. species, and P. species by agar well diffusion methods. All the polymers showed good anti-bacterial and anti-fungal activity, which increased on coordination with the metal ions.