نتایج جستجو برای: electrophilicity iindex

تعداد نتایج: 392  

Journal: :journal of physical and theoretical chemistry 0
mehdi nabati chemistry department, faculty of science, azarbaijan shahid madani university, tabriz, iran

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 an...

2009
Romina Brasca María N. Kneeteman

Introduction Diels-Alder reaction (D-A) is one of the most widely used synthetic strategies for the synthesis of natural products due to its character of generating cyclic systems. By this reaction cyclic compounds characteristic of some families of alkaloids may be directly developed, thus being of high value in synthesis (Biolatto et al., 1999; Della Rosa et al., 2004a). The use of aromatic c...

Journal: :Organic & biomolecular chemistry 2011
Xin-Hua Duan Biplab Maji Herbert Mayr

The kinetics of the reactions of thiocarboxylate and thiocarbonate anions with benzhydrylium ions have been determined in acetonitrile solution using laser-flash photolytic techniques. The second-order rate constants (k) correlate linearly with the electrophilicity parameters E of the benzhydrylium ions, as required by the correlation log k (20 °C) = s(N)(N + E) (J. Am. Chem. Soc., 2001, 123, 9...

2014
C. Guy Goodman Jeffrey S. Johnson

The dynamic kinetic resolution of β-halo α-keto esters via an asymmetric cross-benzoin reaction is described. A chiral N-heterocyclic carbene catalyzes the umpolung addition of aldehydes to racemic α-keto esters. The resulting fully substituted β-halo glycolic ester products are obtained with high levels of enantio- and diastereocontrol. The high chemoselectivity observed is a result of greater...

2015
Mihaiela Andoni Jenel Marian Pătraşcu Cristina Adriana Dehelean Georgeta Maria Simu Raluca Pop

Twelve bis(benzazole) structures with potential ligand character were investigated by means of computational chemistry. Global and local reactivity descriptors within DFT (Density Functional Theory) theory (Fukui functions, chemical potential, hardness, electrophilicity index) have been computed at B3LYP/6-31G(d,p) level of theory. NICS(0) (Nucleus Independent Chemical Shift) index computations...

Journal: :Molecules 2010
Teresita Ruiz-Anchondo Norma Flores-Holguín Daniel Glossman-Mitnik

In this work several natural carotenoids were studied as potential nanomaterial precursors for molecular photovoltaics. M05-2X/6-31+G(d,p) level of theory calculations were used to obtain their molecular structures, as well as to predict the infrared (IR) and ultraviolet (UV-Vis) spectra, the dipole moment and polarizability, the pKa, and the chemical reactivity parameters (electronegativity, h...

Journal: :Physical chemistry chemical physics : PCCP 2012
Utpal Sarkar Munmun Khatua Pratim Kumar Chattaraj

Quantum fluid density functional theory has been used to study the time evolution of various reactivity parameters such as hardness, electrophilicity, entropy, chemical potential, polarizability, electronegativity etc. in a confined environment during time dependent processes like atom-ion collision and atom-field interaction. Responses in the reactivity parameters of the helium atom, in the dy...

2014
Shubha Srivastava Tanweer Alam

Quantum mechanical calculations of different energies components of 1,10-phenanthroline in ground state were carried out by DFT method , in isolated state and in various solvents to study the effects of solvents on various energy components and global properties. The solvation energy, chemical potential, hardness, electrophilicity of 1,10-phenanthroline were calculated with the help of computed...

Journal: :journal of physical & theoretical chemistry 2013
fereshteh naderi rahimeh bagheri mohammad yari

the effects of halogens; fluorine, chlorine and bromine, on the stability and multiplicity of phenylcarbenes / silylenes/ germylenes structures are compared and contrasted at b3lyp/6-311++g**//b3lyp/6-31+g* level. the singlet-triplet energy gaps, δes-t , values for all the above speciesincrease through fluorinated up, δes-ts and δehomo–lumos support the stability of the singlet statesinspite of...

Journal: :journal of physical and theoretical chemistry 0
reza soleymani young researchers and elite club, shahre-rey branch, islamic azad university, tehran, iran

influence of aluminum, gallium, indium- doping on the boron-nitride nanotubes (bnnts) investigated with density functional theory (dft) and hartreefock (hf) methods. for this purpose, the chemical shift of difference atomic nucleus was studied using the gauge included atomic orbital (giao) approch. in the following, structural parameter values, electrostatic potential, thermodynamic parameters,...

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