Khadija Shahid

Organotin(IV) Derivatives as Biocides: An Investigation of Structure by IR, Solution NMR, Electron Impact MS and Assessment of Structure Correlation with Biocidal Activity

A brief account is given of the synthesis, structural chemistry and the antibacterial, antifungal and cytotoxic effects of organotin complexes of 2-[(2,4-dichloroanilinocarbonyl)]benzoic acid. The unimolar and bimolar substitution products have been characterized by elemental analysis and spectral studies, including IR, 1H NMR, 13C NMR, 119Sn NMR, and mass spectra. The data support the binding of the oxygen atom to the tin atom in [R2Sn(OOCR’)2] and [R3Sn(OOCR’)] (R = Me, Bu, and Ph, R’ = 2-[(2,4-dichloroanilinocarbonyl)]benzoic acid). Based on these studies, with a coordination number of four, a distorted tetrahedral geometry has been proposed for the resulting derivatives in solution. The free ligand (R’/COOH) and its respective tin complexes were tested in vitro against a number of microorganisms to assess their biocidal properties and to correlate them with the structures of the derivatives.

Organotin(IV) Complexes of Aniline Derivatives. I. Synthesis, Spectral, and Antibacterial Studies of Di- and Triorganotin(IV) Derivatives of 4-Bromomaleanilic Acid

Organotin(IV) derivatives of the general formulae R2SnL2 and R3SnL where R = Me, n‐Bu, n‐Oct, Ph and Bz and HL = 4‐bromomaleanilic acid have been synthesised. These compounds were characterized by elemental analyses, infrared, multinuclear (1H, 13C, 119Sn) NMR and mass spectrometry. Biological screenings were performed in order to establish their biological activity.

1H, 13C, AND 119Sn NMR, IR, MASS, THERMAL, AND BIOLOGICAL STUDIES OF ORGANOTIN(IV) DERIVATIVES OF 4-p-(CHLOROPHENYL)-2-PHENYL-5-THIAZOLEACETIC ACID

ABSTRACT A series of di- and triorganotin(IV) carboxylates of 4-p-(chlorophenyl)-2-phenyl-5-thiazoleacetic acid has been synthesized and characterized by various instrumental techniques such as infrared, 1H, 13C, 119Sn NMR, mass spectrometry and thermal analysis. These compounds were also tested for their antibacterial and antifungal activities to study their biological significance.

Coordination behavior of the carboxylate group in organotin(IV) derivatives of 2-[(2′,4′,6′-tribromophenylamido)]benzoic acid and 3-[(2′,4′,6′-tribromophenylamido)]propenoic acid: Spectroscopic studies

The complexes of two organic carboxylates (containing {O,O}-donor atoms) with Me2Sn(IV)Cl2, n-Bu2Sn(IV)Cl2, Bz2Sn(IV)Cl2, Oct2Sn(IV)O, Me3Sn(IV)Cl, n-Bu3Sn(IV)Cl, Ph3Sn(IV)Cl, Ph3Sn(IV)Cl, and Bz3Sn(IV)Cl having ligand-to-metal ratios of 1: 2 and 1: 1 were prepared by two different methods. The FT-IR spectra clearly demonstrated that organotin(IV) moieties react with {O,O}-atoms of the ligands. It was found that in all cases the COO− group was acting as bidentate in the solid state. The 119Sn NMR data revealed that the organotin(IV) moiety has a tetrahedral geometry in non-coordinating solvents. The biological activity of these compounds was compared with that of their precursors, and all the synthesized compounds show significant antibacterial activity. The antifungal activity of the complexes against six plant pathogens has been estimated. The complexes display marked toxicity against these fungi and are more fungitoxic than free acids. The compounds have also shown significant cytotoxicity against Brine Shrimp (Artemia salina).

Spectral characterization and biocidal activity of organotin(IV) (E)-3-[(2′,6′-dichlorophenylamido)]propenoates

Biocidal and spectroscopic aspects of organotin(IV) complexes with (E)-3-[(2′,6′-dichlorophenylamido)]propenoic acid are described with support of elemental analysis. IR, 1H, 13C, 119Sn NMR and mass spectral data suggest that the ligand is bidentate, coordinating through oxygen atoms and that diorganotin(IV) complexes are six-coordinate. Triorganotin(IV) carboxylates exist as pentacoordinated trigonal bipyramidal complexes in the solid state and tetrahedral ones in solution. The complexes have been screened against bacteria, fungi and brine-shrimp larvae to assess their biological activity.

Organotin(IV) complexes of 4-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acid: Synthesis, spectral characterization and biological applications

Abstract4-(2,5-Dioxo-2,5-dihydro-1H-pyrrol-1-yl)benzoic acid and its complexes with methyl-, n-butyl-, phenyl-, benzyl- and octyl-tin have been synthesized and characterized by elemental analysis and spectral studies. The geometry around the tin atom has been deduced from both solid and solution studies. These complexes were also tested against different bacteria and fungi to determine their toxicity. LD50 data was also calculated using the Brine Shrimp method.

The chemistry, properties, and characterization of organotin(IV) complexes of 2-(N-naphthylamido)benzoic acid

2-(N-naphthylamido)benzoic acid was synthesized by the reaction of phthalic anhydride with naphthylamine in glacial acetic acid at room temperature. Complexes 1–9 were synthesized under reflux in good yield with general formula R4− n SnL n (R = Me, n-Bu, Ph, n-Oct, Bz and n = 2, 3), which were studied by microanalysis, IR, NMR (1H, 13C, 119Sn), and mass spectrometry. Cytotoxicity of the synthesized compounds was checked against Brine-shrimp larvae. In vitro activities against some Gram-positive and Gram-negative bacteria and fungi were also determined. Antimicrobial activities show that species with tetrahedral geometry in solution are more toxic.

Organotin(IV) Complexes of 2-[(2′,4′,6′- Trichlorophenylamido)]benzoic Acid: Synthesis, Coordination Chemistry, and Semi-Empirical Study

A new series of organotin(IV) complexes of aniline derivatives, R2SnL2 and R3SnL [where R = Me, n-Bu, n-Oct, and Ph], have been synthesized by the reaction of ligand acid with respective organotin halides in the presence of triethylamine as base or dioctyltin oxide using a Dean–Stark trap for the removal of water under reflux conditions. Experimental details for the preparation and characterization, including elemental analysis, IR, semi-empirical study, multinuclear NMR (1H, 13C, and 119Sn spectra and EI mass spectral studies) of all reported complexes are provided. The IR data indicate that in both di- and triorganotin(IV) carboxylates, the ligand moiety ‒COO acts as a bidentate group in the solid state. Multinuclear NMR data show that triorganotin complexes exhibits a four-coordinated geometry, while diorganotin(IV) complexes show a coordination number greater than four, probably five or six, in solution state. Supplemental materials are available for this article. Go to the publishers online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

Spectroscopic Studies of Biologically Active Organotin(IV) Derivatives of 2-(N-(2,4,6- Tribromophenylamido)propanoic Acid

Herein we describe the synthesis and characterization of compounds having the formulae R2SnL2 and R3SnL, where R = Me, n-Bu, Ph and n-Oct and L = 2-[N-(2,4,6-tribromophenylamido]propanoic acid. All the complexes have been characterized by various spectroscopic methods (IR and 1H, 13C, 119Sn NMR), elemental analysis, mass spectrometry and physical data. These compounds were also screened for their biological activity and found some encouraging results.

Reaction of 9-Borabicyclo(3.3.1)nonane with Alkyn-1-yltin Compounds. Molecular Structure of the 9-Propyn-1-yl-9-borabicyclo(3.3.1)nonane Pyridine Adduct

Trimethyl- and triethyl(propyn-1-yl)tin react with 9-borabicyclo[3.3.1.]nonane (9-BBN) mainly by exchange of the propynyl group against hydrogen, accompanied by numerous side reaction. This is in contrast to the findings for other alkynyltin compounds bearing a second bulky substituent at the C≡C bond. The exchange product, 9-propyn-1-yl-9-borabicyclo[3.3.1]nonane, was isolated as its crystalline pyridine adduct and fully characterised by NMR spectroscopy in solution and X-ray structural analysis in the solid state. Graphical Abstract Reaction of 9-Borabicyclo[3.3.1]nonane with Alkyn-1-yltin Compounds. Molecular Structure of the 9-Propyn-1-yl-9-borabicyclo[3.3.1]nonane Pyridine Adduct