Chemical Review and Letters
Volume:2 Issue: 1, Winter 2019

< p>Oxidation of fullerenes, carbon nanotubes, and graphene, is one of the first proposed and successful approaches for further functionalization of these nano dimension carbon allotropes. Also, the C20 fullerene, as the smallest known carbon cage, is one of the most important species, in the future of nanotechnology. In this regard, the potential energy surface (PES) study suggests that reaction between nitric (V) acid and C20 fullerene, first leads to the production of a relatively meta-stable kinetically allowed intermediate via a [2+3] cycloaddition. After the intermediate is produced, it would subsequently be decomposed to a C20O open-shell fullerene and a HNO2molecule. Such oxidations were observed via the reaction between strong acids and some of the nano-sized carbon allotropes like carbon nanotube CNTs or spherical fullerenes. The results showed that the produced intermediate directly changes to the final product of oxidation, in a fast process.

At first, potassium 2-oxoimidazolidine-1,3-diide (POImD) was prepared of stirring a mixture of imidazolidin-2-one, KOH and H2O overnight. Then, Potassium 2-oxoimidazolidine-1,3-diide was used as a green, novel, fast, efficient and mild catalyst for the synthesis of bis coumarinyl methanes via a one-pot reaction of one equivalent of various aromatic aldehydes and two equivalents of 4-hydroxycoumarin at room temperature in aqueous media. All reactions are performed in the absence of organic solvent in high to excellent yield during short reaction time. The procedure was readily conducted and affords remarkable advantages such as simple work-up, green media and eco-friendly procedure. The catalyst was recovered and reused. Apart from the mild conditions of the process and its excellent results, the simplicity of product isolation and the possibility to recycle the catalyst offer a significant advantage. To the best of our knowledge this is the first report on synthesis of POImD. All of synthesized compounds were characterized by IR, 1H and 13C NMR spectroscopy and elemental analyses.

The reaction of 1,3-diphenylpropane-1,3-dione (HL) ligand with lead(II) nitrate under hydrothermal conditions led to the formation of a novel lead complex with singular structural features. The characterization of title complex was performed by spectroscopy methods such as 1H NMR, UV, and IR and elemental analyses (CHN) and crystal structure of prepared lead (II) complex was determined by single-crystal X-ray diffraction. The facile and productive sonochemical method was used to prepare nano-size particles of the title complex at room temperature. The prepared nano-size-complex was characterized by elemental analysis, scanning electron microscopy (SEM), IR spectroscopy and X-ray powder diffraction (XRD). The nano-size lead oxides that prepared by calcination of the nano-size complex and crystalline bulk complex showed the initial particle size of the precursor is influential on the particle size of the derived PbO nanoparticles. Optical property investigation of the PbO nanoparticles at room temperature showed that the size of PbO nanoparticles has an important role on their optical behavior.

Crude oils are dominant earth resources since composed with large number of hydrocarbons and some of trace compounds especially with corrosive compounds such as sulfur compounds, naphthenic acids and salts. In the current research the major scope was the investigations of the impact of such corrosive compounds on the corrosion of seven different types of ferrous metals in both qualitatively and quantitatively. According to the methodology such corrosive properties of two different types of selected crude oils were analyzed and the chemical compositions of seven different types of selected ferrous metals were detected by the standard methodologies and recommended instruments. The corrosion rates of such metals were determined by the relative weight loss method after certain immersion time periods in both crude oil samples while analyzing the corroded metal surfaces through a microscope. In addition that the decays of metallic elements from metals into crude oil samples were measured and the variations of the initial hardness of metals after the corrosion were measured by Vicker’s hardness tester. Basically there were observed the lower corrosion rates from stainless steels mainly with at least 12% of chromium and sufficient amount of nickel, higher progress of salts on the metallic corrosion at the normal temperatures while comparing with other corrosive compounds, formations of FeS, Fe2O3, corrosion cracks and cavities on the metal surfaces, decay of ferrous and copper from most metals while the immersion into crude oils and small and some insignificantly deductions of the initial hardness of metals.

In this article efficiency of activated carbon as a potent adsorbent of cationic dyes dyes present in waste water was studied in this research. Activated carbon (AC) from starch was used to adsorb methylene blue (MB) from an aqueous solution. Various parameters such as adsorbent concentration, temperature, initial dye concentration, contact time, and pH were investigated and the optimum parameters were determined based on the experimental outcomes. The extent of methylene blue removal increased with the increased in contact time, adsorbent mass, solution pH and amount of adsorbent used. Thermodynamic parameters like the Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) were also determined and they showed that the adsorption process was feasible, spontaneous, and exothermic in the temperature range of 293–333 K. The experimental equilibrium data were analyzed using the isotherms of Langmuir, Freundlich, and Tempkin. Two simplified kinetic models including pseudo-first-order and pseudo-second-order equation were selected to follow the adsorption processes.

In this work, the kinetics and mechanism of free radical polymerization of acrylonitrile (AN) using potassium peroxydisulphate (PDS-K2S2O8) as a water soluble initiator in the presence of synthesized 4,4'-dihexadecyl-1,1'-bipyridine diiumdichloride (DHBPDDC) as multi-site phase-transfer catalyst (MPTC) has been investigated. The polymerization reaction were carried out under nitrogen atmosphere and unstirred condition at constant temperature 60+1°C in ethyl acetate/water biphasic medium. The effects of variation of monomer(AN), initiator(PDS) and catalyst(MPTC) solvent polarity and temperature on the rate of polymerisation (Rp) were ascertained. The order with respect to monomer(acrylonitrile) was found to be unity. The order with respect to initiator and catalyst was found to be 0.51, 0.48 respectively. However, an increase in the polarity of the solvent has slightly increased the rate of polymerization value (Rp). Based on the results obtained, a suitable kinetic mechanism scheme has been proposed to account for the experimental observations and its significance was discussed. The other thermodynamic parameters such as entropy of activation ((∆S#), enthalpy of activation (∆H#) and free energy of activation (∆G#) have been calculated.