Muhammad Aziz Choudhary

Synthesis, characterization, semi-empirical study, and biological activities of organotin(IV) complexes with cyclohexylcarbamodithioic acid as biological active ligand

Cyclohexylcarbamodithioic acid has been synthesized by the reaction of cyclohexylamine with carbon disulfide at room temperature. Its complexes have been synthesized by the reaction of cyclohexylcarbamodithioic acid with organotin(IV) chlorides in 1 : 1/1 : 2 molar ratio. The ligand and complexes have been characterized by elemental analysis, infrared (IR), and multinuclear (1H, 13C, and 119Sn) NMR spectroscopy. Elemental data show good agreement between calculated and found values of carbon, hydrogen, nitrogen, and sulfur. IR data show that the ligand is bidentate and complexes exhibit a five-coordinate geometry in the solid state, which is also confirmed by semi-empirical studies. NMR data show that the complexes exhibit tetrahedral geometry in solution state. The ligand and its complexes were screened for their in vitro mutagenic, antimicrobial, MIC, antioxidant activities, and cytotoxicity. Biological screening data demonstrate that complexes show significant activity against various bacterial and fungal strains and are good antioxidants. The cytotoxicity data show positive lethality for complexes as compared to ligand and can play a very significant role in drug development.

Synthesis, characterization and biological activity of dimethyltin dicarboxylates containing germanium.

A series of diorganotin dicarboxylates of the general formula (CH3)2Sn(OCOCHR3CHR2GeR1)2 where R1=(C6H5)3, (P-CH3C6H4)3, N(CH2CH2O)3, R2=C6H5, H, CH3, P-CH3OC6H4, P-ClC6H4, P-CH3C6H4, R3=CH3 and H, have been synthesized by the reaction of dimethyltin oxide with germanium substituted propionic acid in 1:2 molar ratio in toluene. The H2O formed was removed azeotropically using a Dean and Stark apparatus. All the compounds have been characterized by IR, multinuclear (1H, 13C, 119Sn) NMR, mass and Mössbauer spectroscopies. All compounds were found to have potential activity against bacteria.

Comparative Review on Structure, Properties, Fabrication Techniques, and Relevance of Polymer Nanocomposites Reinforced with Carbon Nanotube and Graphite Fillers

ABSTRACT Owing to their remarkable electrical, mechanical, thermal, catalytic, and optical properties as well as their unique structure, carbon nanotubes and graphite have been exploited to produce high performance and multifunctional composites. The resultant composites are differentiated on the basis of their properties to meet various applications. In the framework of this review article, we have mainly focused on the preparation, structure, and properties of two families of composite materials with an emphasis on the differences between them. Moreover, the current challenges, future prospectives, and applications of carbon nanotubes- and graphite-based materials in sensors and in photovoltaic and energy storage devices (Li-ion battery) have been discussed. GRAPHICAL ABSTRACT

Synthesis of polypyrrole nano/microspheres using cobalt(III) as an oxidizing agent and its ammonia sensing behavior

Polypyrrole (ppy) has been synthesized by employing [Co(NH3)6]Cl3 as a new oxidizing agent under basic condition in aquous solution. The optimized ratio of monomer to oxidizing agent has been taken as 1:2. The reaction was allowed to continue for 24-48 h at room temperature. The as synthesized ppy displayed well defined morphology, which was seemed as time dependent. It was nanospheres at 24 h, micro/nano mixture at 36 h and microspheres and microfibers at 48 h. The FTIR confirmed the formation of ppy due to the presence of characteristics broader ring and N-H stretching vibrations. The XRD showed the development of crystallites only within the fibrous ppy. The thermal and structural correlation was determined using TGA and DSC techniques alongwith SEM. The polymer was found to be considerably more stable as compared with similarly synthesized using other such oxidants. The conductivity of pure polymer and effect of NH3 over its conductivity was analyzed by four probe technique. Its strong potential of NH3 sensing has been confirmed from this technique due to showing linear increase in its conductivity. These results demonstrated that cobalt(III) is a potential oxidizing agent to produce thermally stable nano/microspheres of ppy. Moreover, the material was found quite useful for its characteristics of NH3 sensing that can be applied for other nitrogenous bases.

Synthesis and Structure of the Cyclic Borenium Cation 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride

AbstractThe solid state structure of an N-heterocyclic borane 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride is reported. This molecule features numerous Cl⋯H hydrogen bonds.Graphical AbstractThe crystal structure of 1,1,3,3-tetramethyl-1,3λ4,2-diazaborolidin-1-ium chloride shows multiple C–H⋯Cl interactions in the solid state.

An investigation on the synthesis and catalytic activities of pure and Cu-doped zinc oxide nanoparticles

Abstract The typical polyol reduction method, where PVP was used as capping agent is aimed to synthesize pure and Cu-doped ZnO nanoparticles (NPs). The spherical morphology of as-synthesized NPs was observed under SEM. The NPs having Zn, O, and Cu as major constituents were observed by SEM coupled with EDX. The EDX confirmed the Zn, O, and Cu as major elements of as-synthesized NPs. The X-ray diffraction (XRD) studies demonstrated crystalline hexagonal structure in all the samples. The band gap of the NPs was determined using UV–vis spectroscopy. The catalytic activities of as-prepared material were investigated for the degradation of dyes like; Methyl Blue (MB), Methyl Red (MR), Thymol Blue (TB), and Alizarine Red.S (ARS), in the presence of H2O2. A drastic increase in catalytic activity was observed with the increased concentration of Cu; particularly for MB. All experiments were carried out under mild and environment friendly conditions i.e. without irradiating by sun or UV light. The material was found promising and feasible catalyst for non-photo degradation of dyes, which are present in the wastewaters produced from textile and printing industries.

Synthesis and characterization of Ag@polycarbazole nanoparticles using different oxidants and their dispersion behavior

Abstract Ag nanoparticles (NPs) encapsulated by polycarbazole (PCz) have been synthesized using ion adsorption method. The PCz synthesis around Ag NPs has been performed by adsorbing Ag+1 and Fe+3 oxidants onto Ag NPs, which initiated surface polymerization and thus, Ag NPs@PCz nanocomposite has been synthesized. The morphology of pure NPs and composite NPs was characterized by TEM which also elucidated the effect of oxidant on the core NPs, beside their morphologies and phase contrasts of metal NPs and polymer. The polymer around the surface of core NPs was characterized by FT-IR which proved that PCz was the organic phase of the composite NPs. UV-Vis spectroscopy has been employed to study surface plasmon resonance (SPR) of pure NPs and composite of NP which demonstrated that SPR of core NPs remained preserved after coating with the polymer. Furthermore, Zeta Sizer Nano series has been applied to analyze the dispersion behavior of pure NPs and composite NPs which displayed the greatly improved dispersion behavior of the composite NPs as compared to pure Ag NPs. Therefore, our study proved helpful to analyze the suitability of metal oxidants for PCz based nanocomposite synthesis and determination of their optical and dispersion behavior.

Crystal structure of 4-[(E)-(2-carbamo-thio-ylhydrazinyl-idene)meth-yl]benzoic acid.

The title compound, C9H9N3O2S, is close to planar with an r.m.s. deviation of 0.032 Å. An intramolecular N—H⋯N hydrogen bond closes an S(5) ring. In the crystal, molecules are connected into inversion dimers of the R 2 2(8) type by pairs of O—H⋯O interactions. The dimers are further connected by pairs of N—H⋯S interactions, which also complete R 2 2(8) ring motifs. The chains of dimers are cross-linked by N—H⋯O bonds and hence R 4 2(28) rings are completed. Taken together, these interactions lead to infinite sheets propagating in the (122) plane.

Crystal structure of 4-benzamido-2-hy-droxy-benzoic acid.

In the title compound, C14H11NO4, the dihedral angle between the mean planes of the aromatic rings is 3.96 (12)° and an intramolecular O—H⋯O hydrogen bond closes an S(6) ring. A short intramolecular C—H⋯O contact is also seen. In the crystal, carboxylic acid inversion dimers linked by pairs of O—H⋯O hydrogen bonds generate R 2 2(8) loops. Conversely, the N—H group does not form a hydrogen bond. Aromatic π–π interactions exist at a centroid–centroid distance of 3.8423 (15) Å between the benzene rings. An extremely weak C—H⋯π interaction also is present.