Farooq Ali Shah

Spectral and biological studies of newly synthesized organotin(IV) complexes of 4-({[(E)-(2-hydroxyphenyl)methylidene]amino}methyl)cyclohexane carboxylic acid Schiff base

The new organotin(IV) complexes with 4-({[(E)-(2-hydroxyphenyl)methylidene]amino}methyl)cyclohexane carboxylic acid (HL, Schiff base) were synthesized by the reaction of di- and triorganotin salts in the presence of triethylamine as base or dioctyltin oxide using Dean and Stark trap for the removal of azeotropic water. All complexes were characterized by elemental analysis, IR, NMR (1H and 13C) and mass spectrometry. The IR data indicate that in both di- and triorganotin(IV) carboxylates, the ligand moiety -COO acts as a bidentate group in solid state. Multinuclear NMR data show that triorganotin complexes exhibit the four-coordinated geometry, while diorganotin(IV) complexes show the coordination number greater than four, probably five or six, in solution state. These compounds were screened for antibacterial activities against six pathogenic bacterial strains. The activities were measured in terms of inhibition zones (mm). Antifungal activity was determined against six pathogenic fungal strains, cytotoxicity by the brine shrimp lethality assay. Results for antibacterial and antifungal activity, and cytotoxicity of these compounds demonstrate that complexes exhibit significant biological activity with few exceptions.

3-(3,5-Dichloro-anilinocarbon-yl)propionic acid.

The crystal structure of the title compound, C10H9Cl2NO3, consists of dimers due to intermolecular O—H⋯O hydrogen bonding forming an R 2 2(8) ring through the carboxyl groups. These dimers are linked to each other by intermolecular hydrogen bonds between the amine group and the adjacent carbonyl O atom. A single C—Cl⋯π interaction is also observed between the chloro-substituted aromatic rings.

CTAB–tributylstannic[3-(3′,4′-dichlorophenylamido)propanoate] interaction: a tool for predicting organotin(IV) complex–cell membrane interaction parameters

This study attempts to explain the bioavailability, permeability, and interaction parameters of organotin(IV) derivatives with the cell membrane. For this purpose, tributylstannic[3-(3′,4′-dichlorophenylamido)propanoate] was synthesized and characterized by elemental analysis and spectroscopic methods (Fourier transform infrared spectroscopy (FT-IR), 1H, 13C, 119Sn NMR). The organic anion was found to act as monodentate O-bound ligand in solution. Cationic surfactant cetyl N,N,N-trimethylammoniumbromide (CTAB) was used to study the interactions of the organotin(IV) complex with positively charged molecules of the surfactant acting as a model cell membrane. The thermodynamic parameters of complex–CTAB interaction concluded that the complex is located in the peripheral region of CTAB micelles. The redshifts in the UV spectra of the complex confirmed its solubilization into micelles. The two carbonyl oxygen atoms were found to be binding sites of the complex with CTAB.

Organotin(IV) complexes of 4,5-dimethoxy-2-nitrobenzoic acid: Synthesis, characterization, and biological activity

A new series of organotin esters has been derived from the condensation of organotin oxides/halides with 4,5-dimethoxy-2-nitrobenzoic acid. Their spectroscopic investigations have been carried out both in solution and solid state. Experimental details for the preparation and the structural characterization (by FTIR, NMR, XRD, and EI mass spectral analysis) are provided. Based on spectroscopic results, the ligand appeared to coordinate to the Sn atom through the COO moiety. Single crystal analysis has shown a bridging behavior of ligand in tributyltin(lV) derivative. Bioassay results have shown that these compounds have good antibacterial, antifungal and cytotoxicity activity, with few exceptions.

3-[(3,4-Dichloro-phen-yl)amino-carbon-yl]propionic acid.

In the title compound, C10H9Cl2NO3, inversion dimers occur due to pairs of intermolecular O—H⋯O hydrogen bonds from the carboxyl groups forming R 2 2(8) loops. The dimers are linked into C(4) chains along the a axis by intermolecular N—H⋯O links. A short intramolecular C—H⋯O contact occurs in the molecule.

4-[(2-Fluoro­phen­yl)amino]-4-oxo­butanoic acid

The crystal structure of the title compound, C10H10FNO3, contains dimers of the asymmetric unit, with R 2 2(8) rings arising from intermolecular O—H⋯O hydrogen bonding through the carboxylate groups. Adjacent dimeric units are connected to each other through one N—H⋯O and two C—H⋯O intermolecular hydrogen bonds. C—H⋯O hydrogen bonds involving the aromatic ring and the O atoms of two carboxylate groups form an R 3 3(7) ring. The crystal structure is further stabilized by C—H⋯F interactions, giving rise to a three-dimensional network.

(Z)-3-[(2-Fluoro­anilino)carbon­yl]prop-2-enoic acid

In the title molecule, C10H8FNO3, the dihedral angle between the fluorophenyl group and the essentially planar [within 0.064 (3) Å] COC=CCOOH unit, which has a Z configuration, is 19.99 (14)°. There is an intramolecular O—H⋯O bond in the molecule involving the acid –OH group and the adjacent carbonyl O atom. In the crystal, intermolecular N—H⋯O bonds lead to the formation of polymer chains propagating along [011].

(2Z)-4-[(2-Hy­droxy­phen­yl)carbamo­yl]prop-2-enoic acid

In the title compound, C10H9NO4, the 2-hydroxyanilinic and the 4-oxobut-2-enoic acid groups are almost planar, with r.m.s. deviations of 0.0086 and 0.0262 Å, respectively. The dihedral angle between the two groups is 6.65 (1)°. Intramolecular N—H⋯O, C—H⋯O and O—H⋯O hydrogen bonds form S(5), S(6) and S(7) ring motifs. In the crystal, the molecules are dimerized due to C—H⋯O and O—H⋯O intermolecular hydrogen bonds, with R 2 2(8) ring motifs. The dimers are interlinked into polymeric chains along [010] with R 4 3(13) ring motifs by C—H⋯O, N—H⋯O and O—H⋯O hydrogen bonds.