In these studies, we had observed polyaniline (PANI) supported p-toluene sulfonic acid (TsOH) and FeCl3 (PANI- TsOH, PANI-FeCl3) as excellent reusable solid acid catalysts for the synthesis of 1, 8-dioxo-octahydroxanthene derivatives 4(a-g) under solvent-free grinding method at mild conditions. Additionally, in the same optimized condition ferric nitrate nonahydrate also acted as (non-reusable) very reactive inexpensive Lewis acid catalyst. The ferric nitrate nonahydrate lost its activity in the form of Clayfen (Clay-supported ferric nitrate) catalyst.

A series of some new (E)-2-(arylbenzylidene)-2-((4-methoxyphenyl)amino)acetohydrazides 4(a-j) have been conveniently synthesized by intermolecular oxidative cyclization of (E)-2-(arylbenzylidene)-2-[(4-methoxyphenyl)amino]acetohydrazides promoted by iodobenzene diacetate as an oxidant. The structures of the synthesized compounds have been confirmed by 1H NMR, IR, MS and elemental analysis. All the synthesized compounds were tested for their inhibitory action against clinically isolated strains i.e., Bacillus subtilis, Staphylococcus aureus, Xanthomonas campestris, Escherichia coli and Fusarium oxysporum. Compounds 4f (21-28 mm, 73.8 %), 4i (20-24 mm, 72.4 %) and 4j (21-27 mm, 71.6 %) demonstrated good antimicrobial activity against all the tested bacterial and fungal strains.

Electron impact (EI) mass spectrometer apparatus has been used to monitor the relative intensities of ion clusters of the type Xn(H2O)n where X is 3-arylpyrimido[4,5-c]pyridazine-5,7(6H,8H)-diones (1a-d), 3-aryl-7-thioxo-7,8-dihydro-6H-pyrimido[4,5-c]pyridazine-5-ones (2a-d) and n = 1, 2. The m/z of selected fragments obtained from 1a-d and 2a-d show a clustered water molecule due to strong intermolecular H-bonding between fragment and clustered water molecule.

2-(5-Chloro-2-phenoxyphenyl)hydrazine was converted to corresponding 3H-indole by Fischer method utilizing the isopropyl methyl ketone in acetic acid. The reaction of 3H-indole with Vilsmeier-Haack reagent furnished aminomethylene malonaldehyde in excellent yield while the reactions of malonaldehyde with hydrazine, arylhydrazines, amines, cyanoacetamide and hydroxylamine hydrochloride, led to the corresponding pyrazole derivatives, enamines, cyanopyridone, and cyanoacetamide derivatives respectively.

An efficient, green, and facile four-component reaction for the preparation of pyrano[2,3-c]pyrazole derivatives through the condensation reaction of aryl aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate or phenyl hydrazine in the presence of commercially available organocatalyst sodium benzoate under aqueous condition is reported. The products are produced with high yields and in shorter reaction times. It also is mild, safe, green and environmental friendly.

The dicompartmental macrocyclic ligand (L2)2- was prepared by [1:1] cyclic condensation of N,N?-dimethyacetate-N,N?-ethylene-di(5-methyl-3-formyl-2-hydroxybenzylamine with 1,3-diaminopropane. The ligand includes dissimilar N(amine)2O2 and N(imine)2O2 coordination sites sharing two phenolic oxygen atoms and containing two methyl acetate pedant arms on the amine nitrogen donor atoms. A series of mono- and bimetallic complexes were synthesized and characterized on the basis of elemental analysis, molar conductance measurement, IR and UV-Vis spectroscopy techniques. It was found that during the cyclization process the copper (II) displaced from the N(amine)2O2 to the N(imine)2O2 coordination site and one of the methyl acetate pedant arms is dissociated. The heterodinuclear complex of [ZnL2Cu(?-OAc)]+ was prepared by a transmetallation reaction on the [ZnL2Zn(?-OAc)]+ by Cu(II). The characterization results showed that the two metal ions are bridged by two phenolic oxygen atoms and an acetate group, providing distorted five-coordination geometries for the both metal ions.

In the current work, beach sand (BS) and beach sand coated with polyaniline (BS/Pani) were used as an efficient green adsorbent for dye removal from aqueous solutions. Methylene blue (MB) was chosen as a test probe for the evaluation of the selected adsorbents for dye removal efficiency. The adsorption experiments were carried out in batch system and the effect of some important empirical parameters affecting adsorption processes were then investigated. The experimental data were also analyzed by Langmuir and Freundlich adsorption models. Based on the correlation coefficient values obtained (R2), it was found that equilibrium data for both adsorbents fitted well with both models. Adsorption data were also examined by pseudo-first-order and pseudo-second-order models and their respective rate constants were estimated. It was found that sorption of MB dye onto BS/Pani is fitted very well with pseudo-second-order kinetic model. Using the equilibrium concentration constants obtained at different temperatures, important thermodynamic parameters of the sorption process were calculated. It was found that the chemically modified beach sand is an effective and low cost adsorbent for dye removal from aqueous solutions.

A new durable antibacterial cotton fabric was successfully prepared by free-radical graft copolymerization of acrylic acid (AA) and itaconic acid (IA) onto a cotton fabric in an aqueous medium. Ammonium persulfate (APS) was used as the initiator in the presence of a crosslinker, methylene bisacrylamide (MBA). The nanocomposite hydrogel was obtained from in situ formation of silver nanoparticles from reduction of silver cations by sodium borohydride. A proposed mechanism for nanocomposite formation was suggested and the effect of ratio of IA to AA on water absorbency discussed. FTIR, UV-Vis, X-ray, and scanning electron microscopy were employed to characterize the structure of the prepared superabsorbent. The antibacterial activity of the hydrogel was tested qualitatively and quantitatively. Results showed that the silver nanoparticle-loaded fabric has potent antibacterial activity to Escherichia coli Gram-negative bacteria.

Imines of six new quinolin-5-ylamine derivatives 3(a-c) and 5(a-c) were synthesized by the reaction of quinolin-5-ylamine (1) with different aldehydes 2(a-c) and ketones 4(a-c). The chemical structures of the compounds were confirmed by UV-visible, FT-IR and 1H NMR spectral study. New compounds were screened for the antioxidant activity by DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Butylated Hydroxytoluene (BHT) was used as standard. All the compounds showed DPPH radical scavenging activity, where compound 3c was the best radical scavenger.

In this study, for the first time we report a highly selective and sensitive lutetium ions chemical optical sensor based on immobilization of a asymmetrically S–N Schiff’s base, namely N-(thien-2-ylmethylene)pyridine-2,6-diamine (TPD) on a triacetylcellulose membrane. This optode exhibits a linear range of 5.0 ×10-7 –1.0 ×10-5 M of the Lu(III) ion concentration with a detection limit of 9.3 ×10-8 M at a wavelength of 336 nm. The influence of responsible factors for improving sensitivity of the sensor was studied and identified. Response time of the newly designed optode was within 20-30 s depending on the Lu(III) ion concentration. Response of the optical sensor is independent of the pH of the solution in the range of 3.0–9.0. It manifests advantages of fast response time, low detection limit and most significantly, very good selectivity with respect to a number of lanthanide ions. The sensor can readily be regenerated with thiourea solutions and its response was reversible and reproducible. This optode was applied to the determination of Lu(III) in aqueous and CRM samples.