Fiaz Ahmed

SYNTHESIS, SPECTROSCOPIC CHARACTERIZATION, AND BIOLOGICAL APPLICATIONS OF ORGANOTIN(IV) DERIVATIVES OF 2-(N-MALEOYL)-3-PHENYLPROPANOIC ACID

ABSTRACT In an effort to develop new organotin materials for investigation and biocidal evaluation, a series of compounds with the general formula R4−nSnLn (where R=CH3, n-C4H9, C6H5, C6H5CH2 and L=2-(N-maleoyl)-3-phenylpropanoic acid anion) have been synthesized, and characterized by elemental analyses, IR, multinuclear (1H, 13C and 119Sn) NMR and mass spectrometry. The biological activity of these compounds against various bacteria and fungi has been investigated. All of the compounds were found to be active against the tested fungi with a few exceptions. These compounds also showed significant antibacterial activity. LD50 data show that the investigated compounds also have significant toxicity.

Interaction of Naproxen with transition metals: synthesis, characterization, anti-inflammatory activity and kinetic studies

Coordination complexes of transition metals (Co, Ni, Cu, Fe, Cr, Ru, Ir, Mn, and Zn) with 6-methoxy-α-methyl-2-naphthalene acetic acid (Naproxen) and triphenylphosphine have been synthesized and characterized by conductance, elemental analysis, UV-Vis, AAS, and FT-IR spectroscopy. The elemental analyses data reveal the presence of 1:1 (metal : ligand) stoichiometry and the IR data suggest that naproxen functions as a bidentate ligand in coordination with transition metals. The anti-inflammatory assays of these complexes have significant effect.

trans-Di­chloro­(di­cyclo­hexyl­amine)(tri­phenyl­phosphine)­palladium(II)

In the crystal structure of the title compound, [PdCl2(C12H23N)(C18H15P)], the Pd atom is four-coordinate in a nearly square-planar environment, with Pd—Cl = 2.2974u2005(6) and 2.3055u2005(7)u2005A, Pd—N = 2.1573u2005(17)u2005A and Pd—P = 2.2504u2005(7)u2005A. Both cycloxadhexyl rings adopt chair conformations.

Thermal degradation analysis of organotin(IV) esters

The di- and tri-organotin(IV) complexes of n-butyl hydrogenphthalate and (Z) 3-(4-nitrophenyl)-2-phenyl-2-propenoate were subjected to thermal decomposition by mean of thermogravimetry (TG). The decomposition occurred in steps and the kinetics of every set of reactions was determined using the method described by Coats and Redfern. These results were analyzed to establish the decomposition kinetics and, hence, to calculate the activation energies. The activation energies were also determined by applying the methods described by Horowitz and Metzger, which yielded comparable results. These results confirm that both the ligands act as bidentate in the solid state.

Chloro-diorganotin(IV) Complexes of Pipyridyl Dithiocarbamate: Syntheses and Determination of Kinetic Parameters, Spectral Characteristics and Biocidal Properties

Organotin complexes of the general formula R2Sn(Cl)L have been synthesized where R = CH3, C2H5, C4H9, C6H5, C7H7, and L = 1-piperidinecarbodithioic acid. These complexes have been characterized by elemental analysis, FT-IR, 1H NMR and mass spectrometry. The spectroscopic and XRD data shows that the dithiocarbamate ligand acts as a bidentate ligand. These complexes were also tested for biocidal activity. Thermal studies of the reported complexes have been carried out to investigate the degradation pattern and thermal stability while kinetic parameters were calculated from the thermogravometric (TG) trace. Silent features of X-ray structures for (1) and (4) are also given.

Kinetic Study of Thermal Degradation of Di-, Chlorodi- and Triorganotin(IV) Complexes of 2-((2,6-Dichlorodiphenyl)amino)benzene Acetate

The organotin complexes of the general formulae R2SnL2, R2SnLCl and R3SnL where R = C4H9, C6H5, and C7H7 and L = 2-[(2,6-dichlorodiphenyl)amino]benzene acetate, were subjected to thermal decomposition by thermogravimetric analysis (TGA). The decomposition of these compounds occurs mostly in two steps. Kinetic parameters such as order of reaction (n), activation energy (Ea), enthalpy (ΔH‡) and entropy (ΔS‡) of activation were calculated by using the Coats and Horowitz methods. The calculated values are in good agreement with observed TG values that confirm the structural integrity of the complexes.

Synthesis, characterization, and biological activity of transition metals complexes with mefenamic acid (NSAIDs)

A new series of transition metal complexes have been synthesized with [(2,3-dimethylphenyl)-amino]benzoic acid (Mefenamic acid) in 1 : 1/1 : 2 M : L ratio. The complexes have been characterized by elemental analysis, FT-IR and UV-Vis spectroscopy. Antifungal, antibacterial, antitumor, antioxidant (DPPH, H2O2 induced DNA damage) activity of the complexes and DNA interaction with the complexes were studied. The results revealed that the ligand and most of synthesized compounds did not demonstrate significant antibacterial activity unlike [Ni(Mef)(H2O)Cl] that exhibited pronounced activity against F. Solani. Antitumor activity of the products was higher than that of the free ligand.

Synthesis, Characterization and Thermal Studies of Transition Metal Complexes with O-, S-Donor Ligands

Transition metal carboxylates have been synthesized with transition metal chlorides of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II) and Ru(III). The binding ligands are 3-[(4-bromophenylamido)]propenoic acid (L) and diethyl dithiocarbamate. All these compounds have been characterized by elemental analyses, conductivity measurements, UV/Vis, FT-IR spectroscopy and thermal analysis. Semi empirical studies of three compounds have also been carried out for structural elucidation showing that the Cr and Co derivatives have a six coordinated octahedral geometry which is in accordance with the data obtained from elemental analysis, UV/visible and FTIR spectroscopy. Thermal studies of all synthesized derivatives were carried out in a temperature range of 50-1000°C under inert atmosphere. Their kinetic parameters, like activation energy, enthalpy, entropy and order of reaction, were also studied. All complexes decompose at a certain temperature leaving behind metal oxides as residual products. The synthesized complexes showed remarkable anti-bacterial activities with a few exceptions. Selected compounds were also investigated for DNA damage assay. The interaction of selected metal derivatives with DNA and their binding strength were investigated by UV/vis spectroscopy. The increasing order is [CuL(H2O)2]Cl < [RuLL’(H2O)2]Cl < [FeL(H2O)4]Cl2 < [CuLL’ < 3-[(4-bromophenylamido)] propenoic acid.