Harminder Kaur

Synthesis and characterization of some new di- and triorganotin(IV) complexes of Schiff base derived from o-vanillin and acetazolamide using microwaves

Abstract The synthesis, by green methodology using microwaves, of the novel Schiff base LH derived from o-vanillin and acetazolamide and of the corresponding organotin derivatives R2SnL2 (1, R=n-Bu; 2, R=n-Oct) and n-Bu3SnL (3) is reported. The compounds are characterized by elemental analyses; 1H, 13C, and 119Sn NMR; IR; and UV-vis spectroscopy.

Synthesis, spectroscopic and biological studies of diorganotin(IV) and triorganotin(IV) derivatives of albendazole, ofloxacin and 3-carboxypropyldisulfide

Abstract Diorganotin(IV) and triorganotin(IV) derivatives of the types R2SnA (R=n-Bu and n-octyl) and (R3Sn)2A (R=n-Bu), where A is the anion of albendazole {methyl[(5-propylsulfanyl-3H-benzoimidazol-2-yl) amino]formate}, ofloxacin {(RS)-7-fluoro-2-methyl-6-(4-methylpiperazin-1-yl)-10-oxo-4-oxa-1-azatricyclo[7.3.1.05,13] trideca-5(13),6,8,11-tetraene-11-carboxylicacid} and 3-carboxypropyldisulfide, have been synthesized. The complexes 1–9 obtained were characterized by elemental analysis as well as infrared (Fourier transform infrared), nuclear magnetic resonance (1H, 13C and 119Sn NMR) and ultraviolet spectroscopy. On the basis of these spectroscopic studies it was proposed that diorganotin complexes of 3-carboxypropyldisulfide having 1:1 stoichiometry and complexes of albendazole and ofloxacin having 1:2 stoichiometry show tetrahedral geometry around the tin atom with monodentate behavior of the carboxylate group in ofloxacin and 3-carboxypropyldisulfide. Triorganotin complexes of 3-carboxypropyldisulfide having 1:1 stoichiometry and complexes of ofloxacin and albendazole having 1:2 stoichiometry show trigonal bipyramidal geometry. The ligand molecule is bound to the Sn atom through carboxyl oxygen atoms in ofloxacin and 3-carboxypropyldisulfide, and to the nitrogen atom in albendazole. The biological activity of the synthesized complexes 4, 5 and 6 has been screened against Candida albicans.

Structural and Morphological Characterization of Transition Metal (Fe, Co) Doped SnO2 Nanoparticles

Pure and transition metal (Fe, Co) doped SnO2 nanoparticles have been successfully synthesized using sol-gel method having the general formula Sn(1−x)CoxO2 with x = 0, 0.2 and Sn(1−x)FexO2 with x = 0, 0.2, 0.5, 0.7, 1. The synthesis of tinoxide nanoparticles is followed by their characterization by various spectroscopic techniques. X-ray diffraction (XRD) studies depict the crystalline nature of SnO2 nanoparticles . Peak broadness in the XRD patterns indicates the very small size of the nanoparticles. Size of sol-gel synthesized SnO2 nanoparticles observed was lying in the range of 40–70 nm using scanning electron microscopy (SEM). Further Fourier transform infrared (FTIR) spectroscopy was used to confirm the presence of organic solvent in the sol-gel synthesized SnO2 nanoparticles. These sol-gel synthesized SnO2 nanoparticles can have their potential applications in the field of photo-catalysis and solar cells.

Green synthesis, characterization, and DFT calculations of diorganotin (IV) complexes of Schiff bases

GRAPHICAL ABSTRACT ABSTRACT Diorganotin (IV) complexes (1, 2, 3, 4), of the general formula R2Sn(L)m have been synthesized where R = n-But, n-Oct; m = 2 when L1 = N-[(Z)-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carboxamide and m = 1 when L2 = [3,4-bis-{[(E)-(2-hydroxy-3-methoxyphenyl) methylidene]amino}phenyl](phenyl)meth-anone. The prepared Schiff bases and diorganotin complexes have been characterized by elemental analysis, FTIR, and NMR (1H, 13C, and 119Sn) spectroscopic studies. The molecular geometry, thermochemical values, and vibrational frequencies of two complexes in the ground state were calculated using the B3LYP density functional method with LANL2DZ basis set for Sn using Gaussian 09 software. A good correlation of theoretical and experimental results shows that in both the complexes the geometry around the central tin atom is tetrahedral. The studies were further extended to test and compare the in vitro cytotoxic activity of ligands and complexes against MCF-7 cell line by MTT assay. The IC50 values show that cytotoxic activity of ligands increased on complexation with tin metal.

Novel Organostannanes with Assorted Drugs: Synthesis, Spectral, and Potentiometric Studies

Abstract Here, we report on synthesis of some novel derivatives of dibutyltin dichloride/oxide with assorted drugs containing a labile proton of carboxylic acid or alcohol moiety. Ligands used in these reactions are ampicillin trihydrate (ABP), ibuprofen (BPPA), acetylsalicylic acid (ASA), and acetaminophen (APAP). Characterization and structure elucidation of the complexes was achieved by elemental analysis, infrared spectroscopy and multinuclear (1H, 13C, and 119Sn) NMR spectroscopic studies. Their protonation behavior and stability constants were investigated and corresponding thermodynamic parameters were calculated using pH-potentiometric technique. It was suggested on basis of potentiometric studies that the complexes formed are invariably of 1:2 stoichiometry irrespective of ligand-to-metal ratio. The stability constants represented by log β values at 298 K were found to be in the order: ABP > APAP > BPPA > ASA. The free energy of formation of these complexes has a negative value, which shows that formation of the complexes is a spontaneous process. Also, the negative value of standard enthalpy change indicates that reaction of ligands with metal ion is exothermic and this validates the decrease in the value of log β with increasing temperature. Entropy change is positive which seems to be the driving force for complex formation. GRAPHICAL ABSTRACT