Carbon fixation of CO2 via cyclic reactions with borane in gaseous atmosphere leading to formic acid (and metaboric acid); A potential energy surface (PES) study.

Carbon dioxide (CO2), a stable gaseous species, occupies the troposphere layer of the atmosphere. Following it, the environment gets warmer, and the ecosystem changes as a consequence of disrupting the natural order of our life. Due to this, in the present reasearch, the possibility of carbon fixation of CO2 by using borane was investigated. To conduct this, each of the probable reaction channels between borane and CO2 was investigated to find the fate of this species. The results indicate that among all the channels, the least energetic path for the reaction is reactant complex (RC) to TS (A-1) to Int (A-1) to TS (A-D) to formic acid (and further meta boric acid production from the transformation of boric acid). It shows that use of gaseous borane might lead to controlling these dangerous greenhouse gases which are threatening the present form of life on Earth, our beautiful, fragile home.

An Urgent Industrial Scheme Both for Total Synthesis, and for Pharmaceutical Analytical Analysis of Umifenovir as an Anti-viral API for Treatment of COVID-19.

BACKGROUND: This paper aims to reveal an urgent industrial scheme for a fast and facile total synthesis of umifenovir (arbidol) (by one-pot stages) as an antiviral agent for treating the 2019-nCoV virus via inhibiting its viral replication in the human cells. As COVID-19 takes thousands of lives all around the world, it seems that the medicinal resources would not be enough to supply billions of peoples currently living on the planet. Thus, this pandemic and its subsequent impacts on the natural order of our life would be one of the most important threats against the entire human race. METHODS: In this project, we have made attempts to find an operative approach for synthesizing this compound as an active pharmaceutical ingredient (API), which showed it could be effective in inhibiting the newly emerged coronavirus.. RESULTS: The designed scheme uses relatively cheap precursors and contains one pot stage instead of seven time-consuming and more costly linear steps. Moreover, safe and cheap solvents have been used like water and ethanol, instead of toxic ones like methanol and pyridine which could cause rejection of the API in the organic volatile impurities (OVI) test of pharmacopeia analysis, as well as increase the concern of inflammability, explosivity, and carcinogenic properties of those common solvents. CONCLUSION: The most important pharmaceutical analytical methods containing OVI test (mainly ethanol (about 171 ppm) much lower than the limits, by gas chromatography-Flame Ionization Detector (GC-FID) instrument), assay content (about 99.6% by potentiometric titration), and related purity analysis (by high-performance liquid chromatography-Ultraviolet Detector (HPLCUV)) (about 99.8%) were performed and described to give a more clear industrial scheme.

The possibility of using C20 fullerene and graphene as semiconductor segments for detection, and destruction of cyanogen-chloride chemical agent.

Detection of hazardous chemical species by changing the electrical conductivity of a semiconductor matter is a proposed and applied way for decreasing their subsequent unpleasant effects. Recently, many examples of using inorganic or organic materials, polymeric, and also nano-sized species as sensors were reported in which, in some cases, those matters were strongly affective and suitable. In this project, we have made an assessment on whether the graphene segment or C20 fullerene, able to sense the existence of cyanogen chloride NCCl? In order to gain trustable results, the possible reaction pathways along with the adsorption kinetics were investigated. Moreover, the electronic density of states DOS showed that C20 fullerene senses the existence of cyanogen chloride agent with a clearer signal (ΔEg=0.0110eV) compared to the graphene segment (ΔEg=0.0001eV). Also the adsorption energy calculations showed that cyanogen chloride could be adsorbed by the fullerene in a multi-step process (Eads1=-0.852kcalmol-1; Eads2=-0.446kcalmol-1; Eads3=-2.330kcalmol-1).

Selective sensing of ozone and the chemically active gaseous species of the troposphere by using the C20 fullerene and graphene segment.

OZONE is a key species in forming a layer in the atmosphere of earth that brings vita for our planet and supports the complex life. This three-atom molecule in the ozone-layer, is healing the earth's ecosystem by protecting it from dangerous rays of the sun. Until this molecule is in the stratosphere, it would support the natural order of the life; but, when it appears in our environment, damages will begin against us. In this project, we have tried to find a new way for beaconing ozone species in our environment via physical adsorption by the C20 fullerene and graphene segment as a sensor. To find the selectivity of this nano-sized segment in sensing ozone (O3), compared to the usual chemically active gasses of the troposphere like O2, N2, CO2, H2O, CH4, H2, and CO, the density of state (DOS) plots were analyzed, for each interacting species. The results showed that ozone could significantly change the electrical conductivity of C20 fullerene, for each adsorption step. Thus, this fullerene could clearly sense ozone in different adsorption steps; while, the graphene segment could do this only at the second step adsorption (/ΔEg-B/=0.016eV) (at the first adsorption step the /ΔEg-A/ is 0.00eV).

A Theoretical Study on Stepwise- and Concertedness of the Mechanism of 1,3-Dipolar Cycloaddition Reaction Between Tetra Amino Ethylene and Trifluoro Methyl Azide.

The order of reaction, especially in 1,3-dipolar cycloadditions directly affects the products' stereo selectivity. Due to this fact that a wide range of heterocyclic rings of natural products and biologically active molecules are synthesizing via this valuable procedure, understanding about the order of this reaction is so useful in designing the synthesis of different types of heterocyclic species. Therefore, the order of 1, 3-dipolar reaction has been carefully studied by many researchers but it seems that this question is still open despite many valuable answers. Considering this, in the present work, it is attempted to pursue this subject by theoretical investigation of any possible pathway of 1, 3-dipolar reaction of tetra amino ethylene as a highly electron rich dipolarophile and trifluoro methyl azide as an electron poor 1,3-dipole. During the calculations, one, two, and three step mechanism(s) have been found to be possible for the present 1, 3-dipolar reaction.

Synthesis of 9H-furo [2,3-f]Chromene Derivatives by Promoting ZnO Nanoparticles.

Three- component reactions of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone, aldehydes and malononitrile or ethyl cyanoacetate in the presence of nanoparticles of ZnO as catalyst are explained as effective and green synthetic method for generating 9H- furo[2,3-f]chromenes in good yield.

A theoretical study on the reaction pathways and the mechanism of 1,3- dipolar cycloaddition of vinyl acetylene and methyl azide.

1,3-dipolar cycloaddition procedure is one of the most widely practiced methods in order to synthesize heterocyclic compounds. Although, it seems very simple, but, there are numerous precursors of heterocyclic molecules who have more than one positions to react with a 1,3-dipole species. As a result, while using a precursor with more than one position for reaction, it is probable to synthesize several products with different structures. This paper studies all possible interactions of vinyl acetylene, which has two positions for reaction, with methyl azide. This reaction could lead to the emergence of any 1,3-dipolar cycloaddition products. Our ultimate goal is to help researchers to find out how precursors containing both carbon-carbon double, and the triple bonds interact with 1,3- dipolar species. The present study used the DFT calculations at B3LYP/6-311++G(3df,pd) level to check all probable interactions between vinyl acetylene and methyl azide, and determined Potential Energy Surface, and optimized all species.

A theoretical study of substitution effect on an electrocyclization reaction.

A theoretical study of substitution effect on an electrocyclization reaction was performed using DFT method at B3LYP level of theory with 6-311G* basis sets. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactant, transition state (TS), and product were calculated. The considered rate constants and activation thermodynamic parameters were calculated. The results indicated the reaction is low dependent to the temperature. These calculations showed that the reaction proceeds through an asynchronous non concerted mechanism and functional group has a major effect on the reaction.