فهرس المقالات Dipole moment

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  1 - Computational Investigation on Naphthoquinone Derivatives :Nuclear Magnetic Resonance (NMR) and Quantum mechanic
  shamsa sharifi
  Naphthoquinones are natural aromatic compounds that can be discovered in various plant families. In recent times a diversity of biological activities of these compounds has been reported. In most cases, these pharmacological activities are related to redox and acid-base أکثر

  Naphthoquinones are natural aromatic compounds that can be discovered in various plant families. In recent times a diversity of biological activities of these compounds has been reported. In most cases, these pharmacological activities are related to redox and acid-base properties, which can be modulated synthetically by modifying the substituents attached to the 1, 4- naphthoquinone ring, in order to enhance their therapeutic actions. In the current study we used dipole moment and nuclear magnetic resonance (NMR) to depict these molecules properties. The density functional theory (DFT) calculations at the level of B3LYP/6-31G* have been applied to analyze the substituent effect on the electronic structural properties including thermochemical parameters of Naphtoquinone Derivatives in gas phase using Gaussian 98. Dipole moment (Debye), energy of structure formation (HF/Kcal/mol) and point group, NMR parameters such as isotropic shielding (σiso) and anisotropic shielding (σaniso), σ11, σ22, σ33 obtained. Also thermodynamic properties and natural bond orbitals (NBO) were calculated. It dovetails our recent work of electron transfer pathways on Naphtoquinone Derivatives in different replacement is a fundamental step in constructing a knowledge base which will ultimately be of use in many cases. تفاصيل المقالة
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  2 - Investigation of solvent effect on the active site energy of Carbonic Anhydrase and Ribonucleotide Reductase
  M. Heshmat S. Saki M. Khaleghian S. Irani M. Monajjemi
  Enzymes catalyze many biological reactions. The rates of chemical reaction in the presence ofenzymes are, in some cases, accelerated more than 10 orders of magnitude relative to thecorresponding rates in solution.In this paper a comparison between optimized structures o أکثر

  Enzymes catalyze many biological reactions. The rates of chemical reaction in the presence ofenzymes are, in some cases, accelerated more than 10 orders of magnitude relative to thecorresponding rates in solution.In this paper a comparison between optimized structures of two enzyme molecules in aspect ofenergy and dipole moment in different conditions including presence of metallic ion, withoutmetallic ion and in the presence of substrate molecule was performed. The stabilizing effect ofmetallic ion is clearly seen. The calculations were performed with three basis sets: 6-31G, 6-31G*and 6-31G** and 6 different solvents and in vacuum. We conclude that the addition of polarizedfunctions to basis sets cause to create higher energy level of system. تفاصيل المقالة
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  3 - Physicochemical study on some cycloltexa peptide nano rings at body normal temperature; novel biodegradable and biocompadble vectors in drug delivery
  B. Khalili Hadad K. Parivar P. Yaghmaei M. Sayadian
  Nanopartmles have been used as an approach to improve the pharmacodynamic and phannacokinetie propertiesof various drues. Amino acids have been considered to be useful to make such nano particles because ofthocompatithe and biodegradable characteristic. The quantum mech أکثر

  Nanopartmles have been used as an approach to improve the pharmacodynamic and phannacokinetie propertiesof various drues. Amino acids have been considered to be useful to make such nano particles because ofthocompatithe and biodegradable characteristic. The quantum mechanical method that was chosen to analyze inethio hexa peptide nano ring]. The structure of some peptide nanorrigs as well as their dipole moments andenergies have been studied by quantum chemical calculations within the Ousager self-consistent reaction field(SCRF) model zing a Hartree-Fock method (RHF) at the RIIF/STO-30 (5D-7F). Radius of Gyration, Dipolemoment and Ramachandnm Plot are obtained to analyze the physicochemical characteristics of eyelo hexapeptide nano rings. These rings are studied concerning the utilization as nanovehicles. تفاصيل المقالة
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  4 - Theoretical Study of electronic Structure of [CoF6]3" Complex embedded in Nano-Ring
  Mehrnoosh Khaleghian Majid Monajjemi
  Density functional theory calculations (DFT), as well as hybrid methods (B3LYP) for Bi8N18-[CoF6]3- complexhave been carried out to study the non-bonded interaction. The geometry of the 1313N18 has been optimized atB3LYP method with EPR-II basis set and geometry of the أکثر

  Density functional theory calculations (DFT), as well as hybrid methods (B3LYP) for Bi8N18-[CoF6]3- complexhave been carried out to study the non-bonded interaction. The geometry of the 1313N18 has been optimized atB3LYP method with EPR-II basis set and geometry of the [CoF6]3 have been optimized at B3LYP method withDe12-TZVP basis set and Stuttgart RSC 1997 Effective Core Potential. The electromagnetic interactions of the[CoF6]3- molecule embedded in the B13N18 nano ring have been investigated at B3LYP and total atomic charges,spin densities, dipole moment and isotropic Fermi coupling constants parameters in different loops and bonds ofthe B15N18-[CoF613- system have been calculated. Also NBO analysis such as electronic delocalization betweendonor and acceptor bonds has been studied by DFT method. Then we have been investigated the lowestunoccupied molecular orbital (LUMO) and the highest occupied molecular orbital (HOMO) for the lowestenergy have been derived to estimate the structural stability of the Bi8N18-[CoF6]3- system. The Gaussianquantum chemistry package is used for all calculations. تفاصيل المقالة
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  5 - Structure Exploring, IR and UV Spectroscopic Properties of Pomalidomide as a Second-generation of Immunomodulatory Agent
  Reza Ghiasi Rahimeh Rasouli Fatemeh Ebrahimi Shaghaghi Farzaaneh Zaarei
  In this article, the optimized geometry, IR and UV spectra, frontier orbital analysis, natural bond orbital (NBO) analyses, and thermodynamic parameters of pomalidomide were investigated. The calculated structural parameters and stretching frequencies values are compare أکثر

  In this article, the optimized geometry, IR and UV spectra, frontier orbital analysis, natural bond orbital (NBO) analyses, and thermodynamic parameters of pomalidomide were investigated. The calculated structural parameters and stretching frequencies values are compared with experimentalvalues of the investigated compound. Also, the relations of the thermodynamic functions vs.temperatures were fitted by quadratic formulas. تفاصيل المقالة
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  6 - DFT studies of all fluorothiophenes and their radical cations as candidate monomers for conductive polymers
  Saeed Jameh-Bozorghi Hossein Shirani
  In this paper, electronic, structural, and spectroscopic properties of mono-, di-, tri-, andtetrafluorothiophenes and their radical cations are studied using the density functional theory andB3LYP method with 6-311++G** basis set. Also the effects of the number and posi أکثر

  In this paper, electronic, structural, and spectroscopic properties of mono-, di-, tri-, andtetrafluorothiophenes and their radical cations are studied using the density functional theory andB3LYP method with 6-311++G** basis set. Also the effects of the number and position of thesubstituent on the electrochemical properties of the thiophene ring have been studied usingoptimized structures obtained for these molecules and their cations, vibrational frequencies andnuclear chemical shielding constants of these compounds have been calculated and analyzed.The results of this study including charge and spin-density distribution, size and direction of thedipole moment vector, ionization potential, electric polarizability and NICS show that among allof these compounds 3-fluorothiophene as candidate monomer for new conductive polymers,possesses the most suitable conditions for electropolymerization. تفاصيل المقالة