Number 32 Volume 9

Open Access Article

1 - A Computational Study on Tetranitrocarbazole Interaction with Boron Nitride Nanocage (B12N12)
Mohammad Reza Jalali Sarvestani

In this study, tetranitrocarbazole (TNC) interaction with boron nitride nanocluster was evaluated by infrared (IR), natural bond orbital (NBO) and frontier molecular orbital (FMO) computations. The negative values of adsorption energy, enthalpy changes, Gibbs free energ More

In this study, tetranitrocarbazole (TNC) interaction with boron nitride nanocluster was evaluated by infrared (IR), natural bond orbital (NBO) and frontier molecular orbital (FMO) computations. The negative values of adsorption energy, enthalpy changes, Gibbs free energy variations showed TNC adsorption on the surface of B12N12 is exothermic, spontaneous and experimentally feasible. The negative values of entropy changes showed adsorption process is inappropriate due to aggregation in TNC complexes with boron nitride nanocage. The NBO results indicated a monovalent bond is formed between the explosive and the nano-adsorbent with SP3 hybridization and their interaction is a chemisorption. The enhancement of specific heat capacity values of TNC after its adsorption on the surface of nanocage indicated the heat sensitivity of TNC has reduced significantly. Structural parameters including the energy of HOMO and LUMO orbitals, bandgap, electrophilicity, chemical potential, chemical hardness, density and zero-point energy were also calculated and discussed. The remarkable decrease in bandgap after the TNC adsorption on the surface of B12N12 demonstrated that the electrochemical conductivity and electrocatalytic properties decreased after adsorbate interaction with the adsorbent and this boron nitride nanocage can be used for construction of new electrochemical sensor in order to TNC detection and quantitation. Manuscript profile

Open Access Article

2 - A theoretical study on the nature of formaldehyde adsroption on the C58BN heterofullerene using DFT
Ehsan Zahedi majid mozaffari Malihe Arab

In this research adsorption of formaldehyde on the external surface heterofullerene C58BN has been studied by means of density functional theory using the B3LYP/6-31G(d) level of theory. Total electronic energies have been corrected by addition of two gCP and D3 correct More

In this research adsorption of formaldehyde on the external surface heterofullerene C58BN has been studied by means of density functional theory using the B3LYP/6-31G(d) level of theory. Total electronic energies have been corrected by addition of two gCP and D3 correction terms. Adsorption of formaldehyde via the bonding of oxygen atom to boron and carbon atom to nitrogen leads to the delocalization of oxygen lone pairs to the empty orbital of boron atom, formation of a strong covalent bond and consequently stability of system. Topological parameters based on the AIM theory, density of state spectrums, and the maps of molecular electrostatic potentials indicated that the adsorption of formaldehyde on the studied positions are covalent in nature. Manuscript profile

Open Access Article

3 - Review on mycotoxins determination by infrared spectroscopy and chemometrics in Food stuff
Rouhollah Karami-Osboo Mohamd hoseein Shojaee Hassan Yazdanpanah

Mycotoxins are toxic secondary fungi metabolites and grow in most parts of the world and a variety of agricultural products, including dried fruits and cereals, and the toxic metabolites of fungi (mycotoxins) are responsible for many non-communicable diseases in humans More

Mycotoxins are toxic secondary fungi metabolites and grow in most parts of the world and a variety of agricultural products, including dried fruits and cereals, and the toxic metabolites of fungi (mycotoxins) are responsible for many non-communicable diseases in humans and livestock communities. Many methods for measuring toxins in the food chain have been introduced; thin-layer chromatography (TLC), methods based on gas chromatography (GC), high-performance liquid chromatography (HPLC), mass spectrometry liquid chromatography (LC-MS) have been used for mycotoxins determination, these methods are widely used, but they are expensive, time consumable and besides, the original sample will destroy. Therefore, it is very important to identify mycotoxins in food products, by cheap, simple, fast, and non-destructive alternative methods that can even be used in the field. Infrared spectroscopy has been used in quality control of the food industry as a fast and non-destructive method. The potential of the infrared spectroscopy technique has been investigated for the analysis of Fusariotoxins, Aflatoxins, Ochratoxin A, patulin, etc. Due to the various reports of contamination of agriculture products with mycotoxins in Iran, this article review recent studies on the application of infrared spectroscopy and the measurement of the mycotoxins. Manuscript profile

Open Access Article

4 - Cu (I)-Catalyzed C-C and C-N Coupling Reactions from a Theoretical Point of View
Fatemeh Zarkoob Alireza Ariafard

Density functional theory was used to investigate Cu(I) catalytic mechanism for the formation of C-C and C-N bonds by heteroarenes in the presence of aryl halides and alkyl halides. The mechanism cycle started with deprotonating C-H and N-H bonds on heteroarenes. Our st More

Density functional theory was used to investigate Cu(I) catalytic mechanism for the formation of C-C and C-N bonds by heteroarenes in the presence of aryl halides and alkyl halides. The mechanism cycle started with deprotonating C-H and N-H bonds on heteroarenes. Our studies showed that deprotonation occurs through a five-centered transition structure in which the interaction between the nitrogen atoms in the heteroarene with copper caused stability and reduced the energy barrier. Finally, C-C or C-N bonds were formed in the presence of aryl halide or alkyl halide. When an aryl halide was added (C(sp2)–X), the mechanism proceeded through the concerted reaction through oxidative addition of Cu (I). After the transient state, reductive elimination occurred without an energy barrier and led to formation of the product. Our theoretical calculations showed that the mechanism for alkyl halides (C(sp3)-X) differs from aryl halides. The overall mechanism in the presence of alkyl halides is SN2 reaction. However, C-C and C-N bonds are formed by SN2 respectively through oxidative addition of copper and C-N coupling reaction. In both paths, the product was formed without an energy barrier. Manuscript profile

Open Access Article

5 - Dispersive solid-phase extraction for preconcentration of colored effluent in aqueous samples using magnetic carbon nanotubes modified with chitosan
ali moghimi Milad Abniki

In this study, a new technique of solid-phase extraction by chitosan-modified magnetic carbon nanotubes was used for small amounts of colored effluent as an indicator of bromocresol green in aqueous samples and measured by UV-VIS spectroscopy. This technique is a two-ph More

In this study, a new technique of solid-phase extraction by chitosan-modified magnetic carbon nanotubes was used for small amounts of colored effluent as an indicator of bromocresol green in aqueous samples and measured by UV-VIS spectroscopy. This technique is a two-phase system in which the donor phase is aqueous samples containing bromocresol green and the acceptor phase is the chitosan-activated magnetic carbon nanotubes. The experiments were performed in two stages of extraction from aqueous samples and desorption of bromocresol green dyes using ethanol solvent and then the desorbed samples were analyzed via UV-Vis spectrophotometry. This method is cheap, simple, fast, and compatible with many existing device methods. Extraction parameters such as the effect of organic solvent and adsorbent, pH of donor and acceptor phases, extraction time, stirring speed, volume of the donor were optimized and quantitative studies and measurements were performed under these optimal conditions. This technique has many advantages such as; short extraction time, low consumption of organic solvents, elimination of the effect of previous tests, low detection limit and high concentration factor. Acceptable values for concentration and diagnostic factors have been obtained for the extraction of bromocresol green dyes. Manuscript profile

Open Access Article

6 - Modeling and quantitative structure-property relationship (QSPR) study to predict the acidic constants of some chemical compounds using multiple linear regression and support vector machine
mehdi nekoei Abbass Taheri Majid Mohammadhosseini

Modeling and studying the structure-property quantitative relationship (QSPR) to predict the acidic constants of some chemical compounds were performed using multiple linear regression (MLR) and support vector machine (SVM). First, the structure of chemical compounds wa More

Modeling and studying the structure-property quantitative relationship (QSPR) to predict the acidic constants of some chemical compounds were performed using multiple linear regression (MLR) and support vector machine (SVM). First, the structure of chemical compounds was plotted and a suitable group of descriptors was calculated. Then, the step selection method was used to obtain the best descriptors that were most related to the chemical properties of the compounds. Then, linear multiple linear regression (MLR) model and nonlinear vector machine (SVM) model were used to predict the acid constants of the compounds. Statistical data showed that the SVM method was superior to the MLR method. Manuscript profile

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