Tansir Ahamad

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, spectral and antimicrobial studies of a novel macrocyclic ligand containing a piperazine moiety and its binuclear metal complexes

A novel macrocycle 1,16-diaza-7,10-diamino-6,11-dioxo-1,17-bis[2′-hydroxy-5′-aminobenzyl]-piperazine-4,12-cyclododecadiene, [H4L] has been synthesized by a multistep process. The interaction of 5-amino salicylic acid, piperazine and formaldehyde in ethanol gave PC-1, which was reduced into a chloro-derivative PC-2. PC-2 by reacting with ethylenediamine gave a new macrocyclic ligand titled [H4L]. Its binuclear complexes with Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) ions have also been synthesized. The ligand and all metal complexes have been characterized by elemental analysis, IR, 1H NMR, 13C NMR and U.V.Visible spectroscopy. Molar conductance and magnetic moment measurements have also been determined. Microanalytical data revealed 1u2009:u20092 molar ratio of ligand to metal in all the complexes. The spectral and magnetic data indicate that Mn(II), Co(II), Ni(II) complexes show octahedral geometry with two water molecules while Cu(II) and Zn(II) complexes exhibit square planar and tetrahedral environments, respectively. The compounds show significant inhibitory activity against seven bacteria and seven fungi.

New class of anti‐microbial agents: Synthesis, characterization, and anti‐microbial activities of metal chelated polyurea

A new class of metal chelated polyurea have been synthesized by the reaction of toluene 2,4-diisocyanate (TDI) with chelated Schiff base diamines. The synthesized polyurea have been characterized by analytical, spectral, and thermal analysis. The results of TGA ascribed that [Cu(II)-PoU(A)] show better heat resistant properties than other metals chelated polyurea. The antibacterial activities of all the synthesized polymers were determined using the shaking flask method, where 30 mg/mL concentrations of each compound were tested against 10(5) CFU/mL solutions of S. aureus, E. coli, B. subtillis, S. typhi. The number of viable bacteria was calculated by using the spread plate method on agar plates and the number of viable bacteria was counted after 24 h of incubation period at 37 degrees C. All the polymers showed good antibacterial activity. The Cu(II) chelated polyurea show higher zone of inhibition then other due to higher stability constant and may be used in biomedical applications.

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.u2009aeruginosa, 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.

Antimicrobial studies of N - N ′-dicarboxydiethyloxamide and its Co(II), Ni(II), Cu(II) and Zn(II) complexes

Neutral complexes of Cu(II), Ni(II), Co(II), and Zn(II) have been synthesized from the oxamide-based ligand derived from leucine and diethyloxalate. The structural features have been deduced from their microanalytical, IR, UV/Vis, mass, 1H and 13C NMR spectral data. The Co(II) and Ni(II) chelates have octahedral geometries and the Cu(II) chelate is a square-pyramidal geometry. The non-electrolytic and monomeric nature of the complexes is shown by their magnetic susceptibility and low conductance data. The biological activities of the ligand and its metal chelates against gram-positive and negative bacteria and fungi are also reported. All the compounds are antimicrobially active and show higher activity than the free ligand.