نتایج جستجو برای: quantum chemical calculations
تعداد نتایج: 749712 فیلتر نتایج به سال:
Stabilities and quantum molecular descriptors of cyclophoshphamide (an anticancer drug)-functionalized (8,0) zigzag and (4,4) armchair carbon nanotubes (CNTs) complexes in water were studied using density functional theory (DFT) calculations. Two attachments namely the sidewall- and tip-attachments are considered for the model constructions. Calculations of the total electronic energy (Et) and ...
در این تحقیق ? کنفورماسیون های دی پپتیدhco–l-ser-l-ala–nh2و hco–d-ser-d-ala–nh2که در پروتئین های متعددی وجود دارد ? در فاز گازی مورد بررسی قرار گرفته است. محاسبات با استفاده از برنامه گوسین 3 و با بهره گیری از سطح تئوری g*31-6b3lyp/انجام شده است. بدین صورت که ابتدا ساختارهای بهینه و انرژی برای کنفورماسیون های حاصل از چرخش زاویه (c) به فواصل30 درجه از صفر درجه تا 360 درجه محاسبه شدند که سه مین...
since fox-7 (1, 1-diamino-2, 2-dinitroethylene) is a relatively new energetic material, little is known about its physical and chemical properties. therefore, first-principles quantum chemical calculations are used to predict the energies of atoms of fox-7. under gentle heating (thermolysis) is likely to cause hydrogen transfer between molecules, producing highly reactive chemical species. conv...
over the past decade, the chemical behavior of flavonoids as antioxidants has become the subject ofintense experimental research. plants represent a main source of natural antioxidants that might serveas leads for the development of novel drugs. malva sylvestris l. known to have various medicinalproperties since several decade ago, were evaluated for their antioxidant compounds ,most of thesebi...
we have performed quantum-chemical ab initio in various basis sets at the hartree-fock andb3lyp levels for adenine and thymine with the program gaussian98. the dipole,quadrupole, octapole and hexadecapole moments and primitive in nine basis sets for thesemolecules are presented. the most stabilized forms of these molecules are observed in 6-311++g** basis set. we have evaluated coefficient hybr...
more recently medical chemistry research has been focused on proteins that drive and controlcell cycle progression. among them, the cyclin dependent kinases (cdk’s) are a group ofserine/threonine kinases, which rule the transition between successive stages of the cell cycle. theactivity of cdk’s is regulated by multiple mechanisms, including binding to cyclins, which is a broadclass of positive...
High-resolution FT-IR spectroscopy combined with quantum chemical calculations was used to study the chemistry of OCS-disproportionation over the reduced surface of isotopically labelled, nanocrystalline TiO2. Analysis of the isotopic composition of the product gases has revealed that the reaction involves solely OCS molecules from the gas-phase. Using quantum chemical calculations we propose a...
We performed studies of fluctuating charge, fluctuating dipole, and combined models for substituted benzenes and concluded that dipoles are necessary to avoid errors in important cases. Force fields incorporating fluctuating dipoles for alanine, serine, and phenylalanine were developed that accurately reproduce both relative conformational energies and cooperative many-body energies as given by...
A novel method combined theoretical and experimental study for environmental friendly silver electroplating was introduced. Quantum chemical calculations and molecular dynamic (MD) simulations were employed for predicting the behaviour and function of the complexing agents. Electronic properties, orbital information, and single point energies of the 5,5-dimethylhydantoin (DMH), nicotinic acid (...
In this research at the first Metoprolol drug and its fullerene derivative were optimized. Natural bond orbital (NBO), nuclear Indepndent chemical shift (NICS) and finally IR calculations, for these compounds were carried out at the B3LYP/6-31G* quantum chemistry level. Different parameters such as energy levels, the amount of chemical shift in different atoms, the amount of HOMO/LUMO, chemical...
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