This work exemplifies a simple and rapid method for the synthesis of silver nanodendrite with a novel electrochemical technique. The antibacterial activity of these silver nanoparticles (Ag NPs) against pathogenic bacteria was investigated along with the routine study of optical and spectral characterisation. The optical properties of the silver nanoparticles were characterised by diffuse reflectance spectroscopy. The optical band gap energy of the electrodeposited Ag NPs was determined from the diffuse reflectance using Kubelka-Munk formula. X-ray diffraction (XRD) studies were carried out to determine the crystalline nature of the silver nanoparticles which confirmed the formation of silver nanocrystals. The XRD pattern revealed that the electrodeposited Ag NPs were in the cubic geometry with dendrite preponderance. The average particle size and the peak broadening were deliberated using Debye-Scherrer equation and lattice strain due to the peak broadening was studied using Williamson-Hall method. Surface morphology of the Ag NPs was characterised by high-resolution scanning electron microscope and the results showed the high degree of aggregation in the particles. The antibacterial activity of the Ag NPs was evaluated and showed unprecedented level antibacterial activity against multidrug resistant strains such as Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia and Escherichia coli in combination with Streptomycin.

No abstract

Nanocrystalline zinc was electrodeposited by reducing the Zn 2? ion from acid sulphate bath at room temperature. The effect of reaction parameters on the particle size, nature and spectral characteristics are deliberated. The surface morphology and texture of zinc nanoparticles (Zn NPs) were characterised by high resolution scanning electron microscopy (HR-SEM) and high resolution transmission electron microscopy (HR-TEM). SEM and TEM images showed the Zn NPs were in hexagonal structural morphology. Energy dispersive X-ray analysis reveals the chemical stoichiometry, and purity of the particles formed. The powder X-ray diffraction data indicates that the reflections of Zn NPs correspond hexagonal close packing structure with space group of P63/mmc. The line broadening was analysed by Debye-Scherrer equation and the average crystallite size of the zinc Nps synthesised at room temperature was in the range of 29 nm. WilliamsonHall analysis was used to study the contribution of crystallite size and lattice strain on the peak broadening. The surface plasmon resonance peak for the Zn NPs was observed near the blue shift with optical band gap of 3.38 eV. The influences of the current density, pH, additives, and concentration medium were analysed.

Key indicators: single-crystal X-ray study; T = 293 K; mean (C-C) = 0.002 Å; R factor = 0.047; wR factor = 0.136; data-to-parameter ratio = 17.3.In the title compound, C 18 H 15 N 3 O 3 , the dihedral angle between the mean planes of the quinoline and indole ring systems [r.m.s. deviations = 0.189 (2) and 0.027 (2) Å , respectively] is 88. 65 (5) . The cyclohexene ring of the quinoline ring system adopts an envelope conformation with the central -CH 2 -C atom as the flap. In the crystal, molecules are linked by two pairs of N-HÁ Á ÁO hydrogen bonds, forming inversion dimers, and enclosing R 2

No abstract