Sharif Digital Repository

The charge transfer interaction of two Schiff-bases 2,5-dichloro -bis(thiophen-2-ylmethylene)benzene-1,4-diamine and 2,5-dimethyl-bis(thiophen-2- ylmethylene) benzene-1,4-diamine as donors with I2 and TCNE ethylene as acceptors have been studied spectrophotometrically.
The formation constants and extinction coefficients of charge transfer complexes have been determined by graphical as well as iterative methods. From measurements at different temperatures the thermodynamic functions of the charge transfer complex formation have been studied. The temperature dependence of the K can be used for the determination of the thermodynamic reaction quantities (ΔG, ΔS, ΔH) for linear regression... 

The fused pyrimidine rings have many biological applications such as antibacterial, antiviral, antitumor and anti-inflammation activity. Therefore, their synthesis has attracted many attentions. In this thesis, the synthesis of fused pyrazolopyrimidine rings through two component reaction catalyzed by iodine was investigated. In this reaction, iodine is used to active the imine bond. Low toxicity, availability, low cost and stability to air are some benefits of iodine as a Lewis acid leading to widespread application of I2 in many different organic transformation. Mild reaction conditions, high yields and lower reaction times are among the main advantage of these reactions.
Another part... 

In the method treatment of thermobrachytherapy, the method of this project, simultaneously use of two processes of thermotherapy and brachytherapy is considered, which can be a more effective treatment for the destruction of tumor tissue. In thermotherapy, the temperature of the tissue is artificially raised to a temperature that leads to cell dysfunction resulting in cell death. In brachytherapy, the destruction of defective tissue is done by placing a source in the tissue. In the present project, we supposed to consider both mechanisms simultaneously for treatment at the same time. In this project, radioactive material 125I is used as a source of radiation emission for brachytherapy. In... 

I-131 isotope is one of the most significant radio medicines for treatments of the thyroid cancer and nuclear tomography of thyroid. As for purification of this radioisotope several methods have been developed among which adsorption-desorption on metallic copper is the most promising. The current study is aimed at elaboration of the kinetics behavior of the different types of metallic copper for adsorption of iodine vapor. The used copper samples included plain and silica-supported Cu nanoparticles as well as micronized copper. The silica-supported Cu nanoparticles were prepared by impregnation of highly porous silica (≈500 m2/g) in Cu(NO3)2 solution, heating of the solution to above... 

Graphene is pure carbon in the form of a very thin, nearly transparent sheet, one atom thick. It is remarkably strong for its very low weight. Graphene is a novel particle that can improve adsorption properties. We use graphene for Iodine gas adsorption. Iodine-131 (usually in the chemical form of iodide) is a component of nuclear fallout, and is particularly dangerous owing to the thyroid gland's propensity to concentrate ingested iodine, where it is kept for periods longer than this isotope's radiological half-life of eight days. For this reason, if people are expected to be exposed to a significant amount of environmental radioactive iodine (iodine-131 in fallout), they may be instructed... 

One of the common methods used for treatment of gaseous radioactive wastes in nuclear waste management is adsorption process. Nanoporous materials have found great utility as sorption media because of their large internal surface area and more adsorption sites than other adsorbents, which caused the increasing attention of researchers to use them in the nuclear waste management. Hence in this study, the surface of nanoporous silicates of SBA-15 and MCM-41 modified with d-block elements of the periodic table such as silver, copper, zinc and nickel by wet impregnation method. After characterization by different techniques such as X-ray diffraction, nitrogen gas porosimetry, Fourier... 

Iodine isotopes are among the most significant medical radioisotopes with a wide range of applications in therapy and diagnosis. The I-131 isotope is usually synthesized by irradiation of natural tellurium in atomic reactors. But there is an alternative route in which this isotopes is produced along with two other significant medical radioisotopes (i.e. Mo-99, Xe-131) by neutronic irradiation of uranium in the reactors. To separate iodine isotopes especially in the extraction process of fission fragments, it is necessary to be selective adsorption of iodine on a selective adsorbent. One of the most selective adsorbent for this application is copper. The aim of this study is to compare the... 

Fused pyrimidines have attracted considerable attention recently in synthetic organic chemistry because of their wide range of biological activities pharmaceutical, therapeutic properties, antibacterial, antiviral, antitumor, and anti-inflammatory activities. We have reported a new and efficient synthesis of dihydro and tetrahydro pyrimidines fused to 2H-chromen-2-oneand cyclohex-2-enone and pyrimidine fused to uracil via two component reaction of 4-amino-2H-chromen-2-one, 3-aminocyclohex-2-enone and6-aminouracilto 1-aryl-N,N'-bis(arylmethylene)methanediaminein the present of iodine as catalyst.Molecular iodine has received considerable attention in the last few years due to inexpensive,... 

This thesis encompasses two parallel, but independent subjects as follow: The first part of the thesis deals with synthesis of bimetallic Ni-Au nanoparticles (Bi Ni-Au), and application of them as electrodes in the methanol fuel cells. The Bi Ni-Au nanoparticles for this purpose were synthesized by controlled reduction of HAuCl3 and NiCl3 in the aqueous medium using NaBH4 as reductant and PVP as stabilizer, and immobilized on the surface of a glassy carbon (GC) electrode by means of Nafion polymer. The obtained electrode then was conditioned in an alkaline solution by cyclic voltammetric method in potential range 100 -700 mV (vs. Ag/AgCl). Physicochemical characterizations of the...