چكيده به لاتين
In this thesis, methyl cobaloxime as a model compound for vitamin B12 coenzyme was synthesized through a reductive methylation method and was then characterized. It was revealed that the product obtained from a disproportionative approach with a yield about 39% and characterized by UV-Visible diffuse reflectance spectroscopic (DRS) study, infrared, far-infrared and proton nuclear magnetic resonance (HNMR) spectroscopies possesses a stable cobalt-carbon bond. In order to have a quantitative yield, the chloro cobaloxime was synthesized with a yield about 73%. Quercus brantii (Persian oak) acorns bark extract was exploited as reducing/capping agent in silver nanoparticles synthesis. The SEM-based particle size distribution analysis and antimicrobial susceptibility test of oak acorns bark-extract-mediated silver nanoparticles against bacterial effluent were pointed out to the critical proportion of silver salt to the capping/reducing agent, i.e., to the antibacterial properties that directly depend on the stability of the silver nanoparticles in a colloidal suspension and on the organization ability of tannins containing extract. The platinum nanopartilces were synthesized through a solution-phase polyol synthesis by using polyethylene glycol as complexing/reducing agent. The supersaturation gradient leading to polydispersivity in shape and size was occurred during this method in presence of polyvinylpyrollidone as stabilizing agent by rising temperature to 160 ˚C and consequently reducing it to 100 ˚C. The platinum nanoparticles were characterized by transmission electron microscopy, X-ray diffraction and UV-Visible spectroscopy. It was also found that polyvinylpyrollidone due to the preferential binding to {200} facets of platinum compared with {111} facets, plays also an important role in controlling the morphology of platinum nanocrystallines. Such preference made the {111} surfaces more exposed for reactions. The crude solvent-extracted saponins containing triterpenoid glycosides and terpenes were extracted from Panax ginseng and were identified by TLC techniques. The development of new absorption peak due to the micelle-iodine complexation, enhancement in the absorbance due to the micelle-solubilized lipoic acid, and displacement of monomer-micelle equilibrium to micelle formation in higher monomer concentration region are some of the physicochemical properties in which CMC was estimated to be 0.009% w/v. Chemical compositions of the Gonabad calcined clay were determined by X-ray fluorescence (XRF) technique before and after treatment with acid. From hydrothermal treatment, a mesoporous template was obtained which its pore properties and nitrogen adsorption–desorption isotherms were pointed out to the plate-like- structured mesoporous silica with slit-shaped pores. Metal (hydr) oxides, especially iron oxides, obtained from basification of acid leachate were used to characterize by field emission scanning electron microscopy (FE-SEM) equipped with energy-dispersive X-ray (EDX) analysis. It is concluded that chemical composition of precipitates is prone to change during basification. By exploiting such different approaches and ideas, the following thesis is intended to bring green chemistry and/or nanochemistry aspects closer to common syntheses and/or strategies.
