Density Functional Theory Computational Reexamination of the Anomeric Effect in 2-Methoxy- and 2-Cyano-1,3-dioxanes and 1,3-Dithianes. Stereoelectronic Interactions Involving the Cyano (C≡N:) Group Revealed by Natural Bond Orbital (NBO) Analysis

2018 ◽  
Vol 83 (17) ◽  
pp. 10326-10333 ◽  
Author(s):  
Eusebio Juaristi ◽  
Rafael Notario
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Anomeric Effect ◽  
Functional Theory ◽  
Stereoelectronic Interactions

scholarly journals Tipping the balance: theoretical interrogation of divergent extended heterolytic fragmentations

2020 ◽  
Vol 11 (8) ◽  
pp. 2231-2242 ◽  
Author(s):  
Croix J. Laconsay ◽  
Ka Yi Tsui ◽  
Dean J. Tantillo
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Electric Field ◽  
Ab Initio ◽  
External Electric Field ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Functional Theory

We interrogate a type of heterolytic fragmentation called a ‘divergent fragmentation’ using density functional theory (DFT), natural bond orbital (NBO) analysis, ab initio molecular dynamics (AIMD), and external electric field (EEF) calculations.

Stereoelectronic interaction effects on the conformational properties of 5-methyl-5-aza-1,3-dithiacyclohexane and its analogous containing N, P, O, and Se atoms — A hybrid density functional theory (DFT), ab initio study, and natural bond orbital (NBO) analysis

2010 ◽  
Vol 88 (7) ◽  
pp. 579-587 ◽  
Author(s):  
Davood Nori-Shargh ◽  
Neda Hassanzadeh ◽  
Meisam Kosari ◽  
Parvin Rabieikarahroudi ◽  
Hooriye Yahyaei ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Hybrid Density Functional Theory ◽  
Functional Theory ◽  
Dipole Interactions ◽  
Conformational Properties ◽  
Hybrid Density Functional

Natural bond orbital (NBO) analysis, hybrid density functional theory (hybrid DFT: B3LYP/6-311+G**//B3LYP/6-311+G**), and ab initio molecular orbital (MO: MP2/6-311+G**//B3LYP/6-311+G**) based methods were used to study the electronic delocalization energy (DE), dipole–dipole interactions, and steric repulsions on the conformational properties of 5-methyl-5-aza-1,3-dioxacyclohexane (1) (-phospha- (2), -arsena- (3)), 5-methyl-5-aza-1,3-dithiacyclohexane (4) (-phospha- (5), -arsena- (6)), and 5-methyl-5-aza-1,3-diselenacyclohexane (7) (-phospha- (8), -arsena- (9)). The MP2/6-311+G**//B3LYP/6-311+G** and B3LYP/6-311+G**//B3LYP/6-311+G** results revealed that the axial stereoisomers of compounds 1–9 are more stable than their equatorial stereoisomers. In this regard, the obtained results showed an egregious axial preference for compounds 1, 4, and 7. Importantly, the results showed that the energy differences between the axial and equatorial stereoisomers decrease from compounds 1 → 3, 4 → 6, and also, 7 → 9. The NBO analysis of donor–acceptor interactions revealed that the calculated DE for compounds 1–3 are –21.50, –7.84, and –4.38 kcal mol–1, respectively. The decrease of the calculated DE values from compound 1 to compound 3 could reasonably explain the decrease of the energy differences between the axial and equatorial stereoisomers from compound 1 to compound 3. The correlation between the DE, dipole–dipole interactions, structural parameters, and conformational behaviors of compounds 1–9 has been investigated.

scholarly journals NBO, nonlinear optical and thermodynamic properties of 10-Acetyl-10H-phenothiazine 5-oxide

BIBECHANA ◽  
2017 ◽  
Vol 15 ◽  
pp. 131-139
Author(s):  
Bhawani Datt Joshi ◽  
Manoj Kumar Chaudhary
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Thermodynamic Properties ◽  
Density Functional ◽  
Nonlinear Optical ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Basis Set ◽  
Functional Theory ◽  
Density Functional Theory Level

In this paper, natural bond orbital (NBO) analysis, nonlinear optical and the thermodynamic properties of 10-Acetyl-10H-phenothiazine 5-oxide have been analyzed by employing density functional theory level employing 6-311++G(d,p) basis set. NBO analysis reveals that the intra- intermolecular charge transfer occurs within the molecule leading to the stabilization. The predicted nonlinear optical properties (NLO) like; polarizability and first hyperpolarizabiliy support that the molecule could attract the interests for future investigation.BIBECHANA 15 (2018) 131-139

scholarly journals DFT Study of Molecular and Electronic Structure of Ca(II) and Zn(II) Complexes with Porphyrazine and tetrakis(1,2,5-thiadiazole)porphyrazine

2020 ◽  
Vol 21 (8) ◽  
pp. 2923 ◽  
Author(s):  
Arseniy A. Otlyotov ◽  
Igor V. Ryzhov ◽  
Ilya A. Kuzmin ◽  
Yuriy A. Zhabanov ◽  
Maxim S. Mikhailov ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Electronic Absorption Spectra ◽  
Bathochromic Shift ◽  
Nbo Analysis ◽  
Functional Theory ◽  
Use Of Time ◽  
Molecular And Electronic Structure

Electronic and geometric structures of Ca(II) and Zn(II) complexes with porphyrazine (Pz) and tetrakis(1,2,5-thiadiazole)porphyrazine (TTDPz) were investigated by density functional theory (DFT) calculations and compared. The perimeter of the coordination cavity was found to be practically independent on the nature of a metal and a ligand. According to the results of the natural bond orbital (NBO) analysis and quantum theory of atoms in molecules (QTAIM) calculations, Ca–N bonds possess larger ionic contributions as compared to Zn–N. The model electronic absorption spectra obtained with the use of time-dependent density functional theory (TDDFT) calculations indicate a strong bathochromic shift (~70 nm) of the Q-band with a change of Pz ligand by TTDPz for both Ca and Zn complexes. Additionally, CaTTDPz was synthesized and its electronic absorption spectrum was recorded in pyridine and acetone.

Ab-Initio Study of Physisorption of Hydrogen Cyanide on 2PANI: a Model for Polyaniline Gas Sensor

2016 ◽  
Vol 230 (10) ◽  
Author(s):  
Ali Shokuhi Rad ◽  
Mehri Esfahanian ◽  
Etesam Ganjian ◽  
Habib-allah Tayebi
Keyword(s):  
Density Functional Theory ◽  
Adsorption Energy ◽  
Hydrogen Cyanide ◽  
Density Functional ◽  
Natural Bond Orbital ◽  
Nbo Analysis ◽  
Adsorption Properties ◽  
Ab Initio Study ◽  
Functional Theory ◽  
Contact Information

AbstractWe investigated the adsorption properties of HCN on dianiline (as a model for polyaniline, denoted here as 2PANI) using density functional theory (DFT) by considering the geometry as well as the electronic property. Contact information of 2PANI with HCN at different configurations was studied and the adsorption energy was calculated in each case. UV-vis analysis, density of states (DOS) and natural bond orbital (NBO) analysis were used to study the interaction of HCN with 2PANI at different configurations. Our calculations showed that HCN could be adsorbed on 2PANI with adsorption energy of ∼ −4.3 kcal mol

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