Electrophilicity

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1 - Investigation of relationship with electron configuration of chemical hardness, absolute electronegativity and electrophilicity
Savas, Kaya Cemal Kaya

Chemical hardness (), absolute electronegativity (), and electrophilicity () have importantapplications in inorganic chemistry. These concepts are defined quantitatively as � � �� ,� � �� , � � ��Where I is the ionization energy and A is the electron أکثر

Chemical hardness (), absolute electronegativity (), and electrophilicity () have importantapplications in inorganic chemistry. These concepts are defined quantitatively as � � �� ,� � �� , � � ��Where I is the ionization energy and A is the electron affinity. In thisstudy, graphical method was used to see the relation of electron configuration with chemicalhardness, absolute electronegativity and electrophilicity. For this purpose, sequential ionization ofatoms were considered. In this method, chemical hardness, absolute electronegativity, electrophilicityand effective nuclear charge (Z*) were calculated for all ions formed with sequential ionization of anatom and chemical hardness, absolute electronegativity and electrophilicity with respect to effectivenuclear charge were illustrated in the graphs. Besides, the same charged ions were considered inorder to see more clearly relationship with electron configuration of these three features becausecharge is effective on chemical hardness, absolute electronegativity and electrophilicity. Likewise,chemical hardness, absolute electronegativity and electrophilicity values were calculated and graphsof these three features were plotted with respect to atomic number (Z). As to conclude, it was proventhat chemical hardness, absolute electronegativity and electrophilicity increase in some specificelectron configurations and this means that configuration effect is a more effective factor than radiusand charge. تفاصيل المقالة

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2 - Theoretical study of tetrahedrane derivatives
Mehdi Nabati Mehrdad Mahkam Yaser Gholizade Atani

Tetrahedrane is most strained and the smallest cage compound. It attracts organic chemists because ofits unusual bonding nature and highly symmetrical structure. However, many efforts to isolate theparent tetrahedrane have been unsuccessful because of the high reactivit أکثر

Tetrahedrane is most strained and the smallest cage compound. It attracts organic chemists because ofits unusual bonding nature and highly symmetrical structure. However, many efforts to isolate theparent tetrahedrane have been unsuccessful because of the high reactivity and very short lifetimecaused by the strain in this molecule. Modeling of molecules for determination of structuralproperties of them prior to synthesizing molecule in the laboratory is an important method. Thecomputational chemistry is more completely in understanding a problem. In present study, the densityfunctional theory (DFT-B3LYP) method with 6-31G (d) basis set was used for optimizing andstudying the electronic structural and detonation properties of tetrahedrane derivatives at 298.15 Ktemperature and 1 atmosphere pressure. The results show the tetrahedrane system with more electronwithdrawing groups will be deviated from standard and stable state. And also, the NHNH2, -NHNO2, -NO2 and -ONO2 groups give the detonation property to the tetrahedrane system. تفاصيل المقالة

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3 - Density functional theory study of the structural properties of cis-trans isomers of bis-(5-nitro-2H-tetrazolato-N2) tetraammine cobalt (III) perchlorate (BNCP)
Mehdi Nabati

In present study, the density functional theory (DFT-B3LYP) method with SVP basis set was used for optimizing and studying the electronic structural properties of cis and trans isomers of bis-(5-nitro-2H-tetrazolato-N2) tetraammine cobalt (III) perchlorate (BNCP) as pow أکثر

In present study, the density functional theory (DFT-B3LYP) method with SVP basis set was used for optimizing and studying the electronic structural properties of cis and trans isomers of bis-(5-nitro-2H-tetrazolato-N2) tetraammine cobalt (III) perchlorate (BNCP) as powerful explosives at 298.15 K temperature and 1 atmosphere pressure. And also, Natural Bond Orbital (NBO) population analysis and the molecular electrostatic potential (MEP) surface of the structures were studied by mentioned level of theory. The effect of ligands sites attached to the transition metal (cobalt) at the BNCP isomers was studied on the HOMO-LUMO energies, the electronic chemical potential, the absolute hardness and electrophilicity index. The geometry optimization of the structures shows the octahedral environment around cobalt. The tetrazole nitrogen atoms have large negative charge. The three-dimensional electrostatic potential maps of the isomers show that the negative charge is located on the nitro and perchlorate groups. The NBO analysis shows that the Co-ligand bonds in the near of perchlorate ion are formed from short, strong and sigma bonds. تفاصيل المقالة

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4 - Computational study of chemical properties of Captopril drug and the connected form to Fullerene (C60) as a medicine nano carrier
Roya Ahmadi

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) wereoptimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at theB3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These أکثر

In this research at the first, captopril drug (CA) and its fullerene connected form (FCA) wereoptimized. Natural Bond Orbital (NBO) calculations for these compounds were carried out at theB3LYP/6-31G quantum chemistry level, in the gas phase and the liquid phase. These calculations canbe performed at different accuracy levels depending on the aim of the theoretical study [1]. Forinstance, Density Functional Theory (DFT) can be used to calculate an accurate electronic structure,HOMO and LUMO energies, Mulliken charge of atoms, energetic_orbital levels, chemical hardness,chemical potential and electrophilicity of systems, and finally chemical, physical, biological,pharmacological and industrial of fullerene and fullerene derivatives [47]. Theoretical calculationssuch as NBO are very important to understand the pathways of electron transfer in assemblies.Consequently, the obtained results showed that energy orbital levels decreased considerably bylinking structure of Captopril to structure of fullerene C60. In the study some other characteristicssuch as chemical potential, chemical hardness, electrophilicity in these structures; it was found thatthey changed considerably. These changes show dependency of the results, on power of electronaffinity of C60. In another part, the valence electrons populations for carbons, nitrogen, oxygens andhydrogens atoms in similar position for FCA and CA were compared. Finally the data were comparedand discussed. تفاصيل المقالة

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5 - The influence of Tyrozine on energetic property in Graphene Oxide: A DFT studies
Roya Ahmadi Reza Soleymani

Using the Computational methods, the interaction effect of Tyrosine Amino acid on Graphene wasinvestigated. For this purpose, the Density Functional Theory (DFT) in the ground state of 6-31Gwas used, and the interaction effects of Tyrosine on Graphene was investigated t أکثر

Using the Computational methods, the interaction effect of Tyrosine Amino acid on Graphene wasinvestigated. For this purpose, the Density Functional Theory (DFT) in the ground state of 6-31Gwas used, and the interaction effects of Tyrosine on Graphene was investigated through attachmentto three different base positions. Different parameters such as energy levels, the amount ofChemical Shift in different atoms, the amount of HOMO/LUMO was determined and relatedparameters like Electrophilicity scale, chemical hardness, Chemical potential, and the maximumamount of electronic charge transferred. The Graphene oxide has the capability to act as adrugnano carrier and also as a mixture with special electrical properties. The results of thisinvestigation also show that the attachment of Tyrosine Amino acid, as an organic compound, tothe chemical structure of Graphene can change these capabilities to a great extent and also increasethe role that this mixture already plays in medical, Pharmaceutical, and electronic industries. تفاصيل المقالة

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6 - Efficiency Measurement in Two-Stage Network Structures Considering Undesirable Outputs
AR. Amirteimoori A. Tolooei Eshlaghi&lrm; M. Homayounfar

Data envelopment analysis (DEA) has been proven as an excellent data oriented nonparametric technique to evaluate the relative performance of peer decision making units. Since DEA is introduced in 1978, it has been widely applied to measure the efficiency of a wide va أکثر

Data envelopment analysis (DEA) has been proven as an excellent data oriented nonparametric technique to evaluate the relative performance of peer decision making units. Since DEA is introduced in 1978, it has been widely applied to measure the efficiency of a wide variety of production and operation systems. Recently DEA has been extended to examine the efficiency of decision making units (DMUs) with two-stage network structures or processes, where the outputs from the first stage are intermediate measures that make up the inputs of the second stage. Many researchers developed several DEA based models for evaluating the efficiencies of such systems. This paper considers the performance evaluation of the general two-stage network structures, while each stage may produce undesirable outputs (bad outputs), in addition to desirable and goos outputs. The applicability of the approach in this paper is illustrated by using the Green Hen poultry chain data in Guilan province, Iran. تفاصيل المقالة

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