الفهرس 
Cover EnglishOnly 14 pages are availabe for public view
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Abstract
Catalysts made of small particles of metals such as Pt, Pd and Ni are widely used in the chemical reactions. New generation of catalysts called nano-sized catalysts have been grown in the last few years because the catalytic activity of nanoparticles is greater than other micro-pores or meso-pores structure. This large increase in the catalytic activity is due to the large surface-to-volume ratio in nanoscale Here we report novel synthetic method of Pd & Au nanoparticles based on the reduction of the metal salt with strong reducing agents using piperidine as a capping agent. The shape and size distribution of Pd nanoparticles were characterized by TEM and the optical properties were assessed by UV-Vis spectrophotometer. These metallic nanoparticles capped with piperidine used as a catalyst to prepare acetyl Coumarines by the condensation reaction between ethyl acetoacetate and salicylaldehyde. New Coumarines derivatives have been obtained with faster rate and better yield. The chemical structure of these novel Coumarines has been investigated by using various spectroscopic and analytical techniques such, FT-IR, mass spectrometry and Life time measurements using streak camera as an ultrafast spectroscopic technique. The mechanism of the formation of Bis-acetyl coumarin has been discussed Bis-acetyl coumarin is a novel organic dye which could be used as a fluorescent material, laser dye and also have wide biological applications such as most of the other coumarin derivatives. Hence, all photophysical properties such as\ absorption, emission, stock shift and quantum yield have been investigated Moreover, since metallic nanoparticles such as silver and gold show strong plasmonic effect. The effect of these plasmonic materials on the photophysical properties of acetyl coumarin and Bis-acetyl coumarin has been studied. It is worth to mention that silver enhance the photophysical properties greatly much more than gold, because of the frequency of its plasmonic is in resonance with the absorption band of coumarins The cytotoxicity of the coumarin and silver-coumarin adduct have been studied because of their potential to be used as a photosensitizing and antibacterial agent Keywords: Gold Nanoparticles, Palladium Nanoparticles, Coumarins, Catalyst, Life time measurements, Cytotoxicity, Antibacterial agents.