DFT Correlation of the Site Selectivity of Donor–Acceptor Chemical Interaction

2012 ◽  
pp. 144-161
Author(s):  
Dulal C. Ghosh ◽  
Soma Bhattacharyya
Keyword(s):  
Density Functional ◽  
Chemical Interaction ◽  
Local Density ◽  
Donor Ligands ◽  
Fukui Functions ◽  
Chemical Systems ◽  
Hsab Principle ◽  
Site Selectivity ◽  
Donor Acceptor ◽  
Local Softness

In this study, the time evolution of concept local HSAB principle as a necessary prelude to our jargon of the trade Correlation of the Site Selectivity of Donor–Acceptor Chemical Interaction in terms of the Local Density Functional Descriptors is discussed at length . The authors try to correlate the known facts relating to the formations of some donor acceptor supermolecules such as HCN–BF3,HNC–BF3, H3C–CN–BF3 and H3C–NC–BF3 by the chemical interaction of a well known Lewis acid, BF3 and various donor ligands/Lewis bases like HCN,HNC,H3C–CN, H3C–NC which are inherently structural isomers having multiple donating sites, in terms of the local DFT descriptors like the local softness (s) and fukui functions (f) of such chemical systems. It is also noted that the dynamic chemico-physical process of site selectivity is found to have a very nice correlation in terms of the computed values of the local descriptors namely the fukui functions and the local softnesses. Thus, the authors find that the theoretical descriptors of the local HSAB principle can be efficiently exploited to study the mechanism of site selectivity in a chemical reaction.

Probing the Reactive Center for Site Selective Protonation in a Molecule by the Local Density Functional Descriptors

2014 ◽  
pp. 653-666
Author(s):  
Sandip Kumar Rajak ◽  
Nazmul Islam ◽  
Dulal C. Ghosh
Keyword(s):  
Physical Process ◽  
Density Functional ◽  
Local Density ◽  
Local Descriptors ◽  
Fukui Functions ◽  
Reactive Center ◽  
Site Selectivity ◽  
Local Softness ◽  
Local Density Functional ◽  
Site Selective

In this study, the authors have explored the efficacy of the local density functional descriptors like the fukui functions (f), the local softness (s) and the local philicity as probe for the reactive centers and site selectivity of the chemico-physical process of protonation of some molecules having multiple site for protonation, viz CH3NCO (Methyl isocyanate), CH3NCS (methyl isothiocyanate), NH2OH (hydroxyl amine), NH2OCH3 (o-methylhydroxylamine), CH3NHOH (N-methylhydroxylamine), NH2CH2COOH (glycine), CH3CH(NH2)COOH (alanine) and OHCH2CH2NH2 (ethanol amine). The authors have seen in terms of the numerical values of the local descriptors measures the reactivity (nucleophilicity) of a particular atomic site of a donor center towards a proton. In all cases, it can be said that the dynamic chemico-physical process of site selectivity can nicely be correlated in terms of the computed values of the local descriptors. Thus, it is found that the theoretical descriptors of the DFT can be efficiently exploited to study the mechanism of site selectivity in a chemical reaction.

Probing the Reactive Center for Site Selective Protonation in a Molecule by the Local Density Functional Descriptors

2012 ◽  
pp. 235-249
Author(s):  
Sandip Kumar Rajak ◽  
Nazmul Islam ◽  
Dulal C. Ghosh
Keyword(s):  
Physical Process ◽  
Density Functional ◽  
Local Density ◽  
Local Descriptors ◽  
Fukui Functions ◽  
Reactive Center ◽  
Site Selectivity ◽  
Local Softness ◽  
Local Density Functional ◽  
Site Selective

In this study, the authors have explored the efficacy of the local density functional descriptors like the fukui functions (f), the local softness (s) and the local philicity as probe for the reactive centers and site selectivity of the chemico-physical process of protonation of some molecules having multiple site for protonation, viz CH3NCO (Methyl isocyanate), CH3NCS (methyl isothiocyanate), NH2OH (hydroxyl amine), NH2OCH3 (o-methylhydroxylamine), CH3NHOH (N-methylhydroxylamine), NH2CH2COOH (glycine), CH3CH(NH2)COOH (alanine) and OHCH2CH2NH2 (ethanol amine). The authors have seen in terms of the numerical values of the local descriptors measures the reactivity (nucleophilicity) of a particular atomic site of a donor center towards a proton. In all cases, it can be said that the dynamic chemico-physical process of site selectivity can nicely be correlated in terms of the computed values of the local descriptors. Thus, it is found that the theoretical descriptors of the DFT can be efficiently exploited to study the mechanism of site selectivity in a chemical reaction.

Reactivity Indices for ortho/para Monosubstituted Phenols

2007 ◽  
Vol 10 (1) ◽  
Author(s):  
Nevim San ◽  
Murat Kılıç ◽  
Zekiye Çınar
Keyword(s):  
Photocatalytic Degradation ◽  
Density Functional ◽  
Reaction Rates ◽  
Chemical Hardness ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Degradation Reactions ◽  
The Density Functional Theory ◽  
Local Softness ◽  
Soft Interactions

AbstractThe kinetics of the photocatalytic degradation reactions of twelve ortho/para mono-substituted phenols containing electron-donating or -withdrawing groups have been investigated experimentally. With the intention of determining the most suitable DFT reactivity descriptors, geometry optimizations of the compounds have been performed with the Density Functional Theory DFT at B3LYP/6-31G* level. In order to take the effect of solvent water into account, the calculations have been repeated for the optimized structures by using COSMO as the solvation model. Chemical hardness, softness, electronegativities, Fukui functions, local hardness and softness, local electrophilicities and softness differences for all phenol molecules have been calculated. Correlations between the apparent initial first-order rate constants determined in the experiments and the calculated DFT reactivity descriptors have been examined. Results show that the reactions investigated are electrophilic in nature. The local softness and softness differences correlate well with the reaction rates indicating that soft-soft interactions dominate in the photocatalytic degradation reactions of phenols.

Tautomeric transformations and reactivity of isoindole and sila-indole: A computational study

2014 ◽  
Vol 13 (05) ◽  
pp. 1450041 ◽  
Author(s):  
Reza Ghiasi ◽  
Morteza Zaman Fashami
Keyword(s):  
Density Functional ◽  
Computational Study ◽  
Polarizable Continuum Model ◽  
Band Gap Energy ◽  
Reaction Field ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Quadrupole Resonance ◽  
Local Softness ◽  
Polarizable Continuum

In this work, the tautomeric transformations and reactivity of isoindole and sila-isoindole molecules has been explored using the B3LYP/6-311G(d,p) level of theory in gas and solution phases. These calculations show that isoindole isomer has more stability rather than 1-h-isoindole. There is identical trend in silated species. The frontier molecular orbitals (FMO) and band gap energy calculations were performed at the B3LYP/6-311G(d,p) level in gas and various solvent. Solvent effects have been analyzed by using the self-consistent reaction field (SCRF) method based on polarizable continuum model (PCM) in chloroform, chlorobenzene, dichloromethane and tetrahydrofurane. Thermodynamic parameters calculated at room temperature have been analyzed. Also, electron affinities were computed. Local reactivity descriptors as Fukui functions [Formula: see text] local softness [Formula: see text] and electrophilicity indices [Formula: see text] analyses are performed to find out the reactive sites within molecule. Density functional theory (DFT) calculations were performed to compute nitrogen-14 nuclear quadrupole resonance (NQR) spectroscopy parameters.

scholarly journals Influence of Copper(I) Halides on the Reactivity of Aliphatic Carbodiimides

2020 ◽  
Vol 3 (1) ◽  
pp. 20
Author(s):  
Valentina Ferraro ◽  
Marco Bortoluzzi
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
General Formula ◽  
Electron Density ◽  
Density Functional ◽  
Functional Theory ◽  
Fukui Functions ◽  
Bond Lengths ◽  
Linear Complexes ◽  
Nitrogen Bond

The influence of copper(I) halides CuX (X = Cl, Br, I) on the electronic structure of N,N′-diisopropylcarbodiimide (DICDI) and N,N′-dicyclohexylcarbodiimide (DCC) was investigated by means of computational DFT (density functional theory) methods. The coordination of the considered carbodiimides occurs by one of the nitrogen atoms, with the formation of linear complexes having a general formula of [CuX(carbodiimide)]. Besides varying the carbon–nitrogen bond lengths, the thermodynamically favourable interaction with Cu(I) reduces the electron density on the carbodiimides and alters the energies of the (NCN)-centred, unoccupied orbitals. A small dependence of these effects on the choice of the halide was observable. The computed Fukui functions suggested negligible interaction of Cu(I) with incoming nucleophiles, and the reactivity of carbodiimides was altered by coordination mainly because of the increased electrophilicity of the {NCN} fragments.

scholarly journals DFT investigations on arylsulphonyl pyrazole derivatives as potential ligands of selected kinases

2020 ◽  
Vol 18 (1) ◽  
pp. 857-873
Author(s):  
Kornelia Czaja ◽  
Jacek Kujawski ◽  
Radosław Kujawski ◽  
Marek K. Bernard
Keyword(s):  
Free Energy ◽  
Molecular Orbital ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Chemical Hardness ◽  
Free Energy Of Solvation ◽  
Fukui Functions ◽  
Reactivity Descriptors ◽  
Condensed Fukui Functions ◽  
Charge Partitioning

AbstractUsing the density functional theory (DFT) formalism, we have investigated the properties of some arylsulphonyl indazole derivatives that we studied previously for their biological activity and susceptibility to interactions of azoles. This study includes the following physicochemical properties of these derivatives: electronegativity and polarisability (Mulliken charges, adjusted charge partitioning, and iterative-adjusted charge partitioning approaches); free energy of solvation (solvation model based on density model and M062X functional); highest occupied molecular orbital (HOMO)–lowest occupied molecular orbital (LUMO) gap together with the corresponding condensed Fukui functions, time-dependent DFT along with the UV spectra simulations using B3LYP, CAM-B3LYP, MPW1PW91, and WB97XD functionals, as well as linear response polarisable continuum model; and estimation of global chemical reactivity descriptors, particularly the chemical hardness factor. The charges on pyrrolic and pyridinic nitrogen (the latter one in the quinolone ring of compound 8, as well as condensed Fukui functions) reveal a significant role of these atoms in potential interactions of azole ligand–protein binding pocket. The lowest negative value of free energy of solvation can be attributed to carbazole 6, whereas pyrazole 7 has the least negative value of this energy. Moreover, the HOMO–LUMO gap and chemical hardness show that carbazole 6 and indole 5 exist as soft molecules, while fused pyrazole 7 has hard character.

First principles calculations of structural, electronic and optical properties of InN compound

2015 ◽  
Vol 29 (05) ◽  
pp. 1550028 ◽  
Author(s):  
R. Graine ◽  
R. Chemam ◽  
F. Z. Gasmi ◽  
R. Nouri ◽  
H. Meradji ◽  
...  
Keyword(s):  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Local Density ◽  
Indium Nitride ◽  
Alternative Form ◽  
Full Potential ◽  
Generalized Gradient ◽  
Pressure Derivative ◽  
Electronic And Optical Properties

We carried out ab initio calculations of structural, electronic and optical properties of Indium nitride ( InN ) compound in both zinc blende and wurtzite phases, using the full-potential linearized augmented plane wave method (FP-LAPW), within the framework of density functional theory (DFT). For the exchange and correlation potential, local density approximation (LDA) and generalized gradient approximation (GGA) were used. Moreover, the alternative form of GGA proposed by Engel and Vosko (EV-GGA) and modified Becke–Johnson schemes (mBJ) were also applied for band structure calculations. Ground state properties such as lattice parameter, bulk modulus and its pressure derivative are calculated. Results obtained for band structure of these compounds have been compared with experimental results as well as other first principle computations. Our results show good agreement with the available data. The calculated band structure shows a direct band gap Γ → Γ. In the optical properties section, several optical quantities are investigated; in particular we have deduced the interband transitions from the imaginary part of the dielectric function.

Magnetic Properties of Embedded Rh Clusters in Ni Matrix

1995 ◽  
Vol 384 ◽  
Author(s):  
Zhi-Qiang Li ◽  
Yuichi Hashi ◽  
Jing-Zhi Yu ◽  
Kaoru Ohno ◽  
Yoshiyuki Kawazoe
Keyword(s):  
Magnetic Properties ◽  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Magnetic Moments ◽  
Functional Formalism ◽  
Rhodium Clusters ◽  
Spin Polarized ◽  
Local Density Functional

ABSTRACTThe electronic structure and magnetic properties of rhodium clusters with sizes of 1 - 43 atoms embedded in the nickel host are studied by the first-principles spin-polarized calculations within the local density functional formalism. Single Rh atom in Ni matrix is found to have magnetic moment of 0.45μB. Rh13 and Rhl 9 clusters in Ni matrix have lower magnetic moments compared with the free ones. The most interesting finding is tha.t Rh43 cluster, which is bulk-like nonmagnetic in vacuum, becomes ferromagnetic when embedded in the nickel host.

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