Experimental and theoretical study on the hydrogen bond interactions between ascorbic acid and glycine

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Xuejun Liu ◽  
Xingchen Fan ◽  
Yuxing Wu ◽  
Huiting Ma ◽  
Cuiping Zhai
Keyword(s):  
Hydrogen Bond ◽  
Ascorbic Acid ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Theoretical Study ◽  
Chemical Shifts ◽  
Functional Theory ◽  
Hydrogen Bond Interactions ◽  
The Density Functional Theory ◽  
Quantum Chemistry Calculations

Abstract Cyclic voltammetry, 1H nuclear magnetic resonance and quantum chemistry calculations were applied to explore the hydrogen bond interactions between ascorbic acid (AA) and glycine. The experimental results demonstrate the existence of hydrogen bonds in AA-glycine system, which has a significant effect on the oxidation peak potentials and currents of AA and the chemical shifts of glycine. The formation of hydrogen bonds between AA and glycine were further confirmed by the density functional theory, quantum theory of atoms in molecules and natural bond orbital analyses.

Experimental and Theoretical Study on the Interaction of P-Aminophenol Hydrochloride with H2O

2019 ◽  
Vol 233 (2) ◽  
pp. 303-313 ◽  
Author(s):  
Bingbing Hou ◽  
Peng Peng ◽  
Ping Zhang ◽  
Cuiping Zhai
Keyword(s):  
Hydrogen Bonds ◽  
Density Functional ◽  
Nmr Spectra ◽  
Theoretical Study ◽  
Cathodic Peak ◽  
Absorption Bands ◽  
Functional Theory ◽  
H Nmr ◽  
Hydrogen Bond Interactions ◽  
Atoms In Molecules Theory

Abstract UV-Vis absorption spectra, cyclic voltammetry and 1H nuclear magnetic resonance (1H NMR) spectra were applied to explore the hydrogen bond interactions of p-aminophenol hydrochloride (PAH) with H2O. The results indicated the hydrogen bonds were formed in PAH–H2O system. The anodic/cathodic peak potentials and UV-Vis absorption bands of PAH in H2O could be affected due to the interactions. The results of density functional theory, atoms in molecules theory and natural bond orbital analyses further confirmed the existence of hydrogen bonds between the phenolic hydroxyl, –NH3+ protons and Cl− of PAH and H2O. Furthermore, the π-π stacking was suggested between PAH benzene rings from the 1H NMR spectra at higher concentrations.

Crystal structures of ammonium citrates

2018 ◽  
Vol 34 (1) ◽  
pp. 35-43 ◽  
Author(s):  
Austin M. Wheatley ◽  
James A. Kaduk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Single Crystal ◽  
Crystal Structures ◽  
Density Functional ◽  
Hydroxyl Group ◽  
Powder Diffraction File ◽  
Functional Theory ◽  
Overlap Population ◽  
The Density Functional Theory

The crystal structures of (NH4)H2C6H5O7 and (NH4)3C6H5O7 have been determined using a combination of powder and single crystal techniques. The structure of (NH4)2HC6H5O7 has been determined previously by single crystal diffraction. All three structures were optimized using density functional techniques. The crystal structures are dominated by N-H⋅⋅⋅O hydrogen bonds, though O-H⋅⋅⋅O hydrogen bonds are also important. In (NH4)H2C6H5O7 very strong centrosymmetric charge-assisted O-H-O hydrogen bonds link one end of the citrate into chains along the b-axis. A more-normal O-H⋅⋅⋅O hydrogen bond links the other end of the citrate to the central ionized carboxyl group. In (NH4)2HC6H5O7, the very strong centrosymmetric O-H-O hydrogen bonds link the citrates into zig-zag chains along the b-axis. The citrates occupy layers parallel to the bc plane, and the ammonium ions link the layers through N-H⋅⋅⋅O hydrogen bonds. In (NH4)3C6H5O7, the hydroxyl group forms a hydrogen bond to a terminal carboxylate, and there is an extensive array of N-H⋅⋅⋅O hydrogen bonds. The energies of the density functional theory-optimized structures lead to a correlation between the energy of an N-H⋅⋅⋅O hydrogen bond and the Mulliken overlap population: E(N-H⋅⋅⋅O) (kcal/mole) = 23.1(overlap)½. Powder patterns of (NH4)H2C6H5O7 and (NH4)3C6H5O7 have been submitted to International Centre for Diffraction Data for inclusion in the powder diffraction file.

Theoretical Study on Au-Doped Ge Semiconductor Clusters

2013 ◽  
Vol 634-638 ◽  
pp. 2537-2540
Author(s):  
Xiao Jun Li
Keyword(s):  
Vibrational Frequency ◽  
Density Functional ◽  
Theoretical Study ◽  
Chemical Shifts ◽  
Theoretical Work ◽  
Basis Set ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Germanium Clusters

Structure, electronic property, aromaticity and vibrational frequency of medium-sized Au-doped germanium clusters were systematically explored using the density-functional theory (DFT) in conjunction with the LanL2DZ basis set. Our results show that the endohedrally Au-doped cagelike structures are energetically preferred. The p- and d-states in endohedral Au atom mainly contribute to the chemical bonding at around −6.5 and −10.6 eV for the AuGe10 and AuGe12 clusters. Moreover, the cage aromaticity appears to be an important determination of the electronic stability of the two clusters, reflected by negative nucleus-independent chemical shifts (NICS) values. The theoretical work will be useful and helpful for the understanding in the further application, i.e., cluster-assembled optoelectronic nanomaterials.

DENSITY FUNCTIONAL THEORY STUDY ON THE IONIZATION POTENTIALS AND ELECTRON AFFINITIES OF ADENINE–FORMAMIDE COMPLEXES

2009 ◽  
Vol 08 (02) ◽  
pp. 187-201 ◽  
Author(s):  
KE TANG ◽  
HAI-TAO SUN ◽  
ZHENG-YU ZHOU ◽  
ZHI-ZHONG WANG
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Density Functional ◽  
Electron Attachment ◽  
Ionization Potentials ◽  
Electron Affinities ◽  
Electron Detachment ◽  
Functional Theory ◽  
Hydrogen Bond Interactions ◽  
The Density Functional Theory

The effects of hydrogen bond interactions upon ionization potentials (IPs) and electron affinities (EAs) of adenine–formamide (AF) complexes have been investigated employing the density functional theory B3LYP. It is found that the hydrogen bond interactions between adenine and formamide play a more important role in the process of electron attachment than in the process of electron detachment. Meanwhile, the hydrogen bond interactions facilitate the adiabatical electron detachment and attachment but have different effects on the vertical electron detachment and attachment with different positions of formamide. Furthermore, when the complexes were dissociated to the free monomers, the processes AF - → A - + F and AF + → A + + F are energetically preferable for AF- and AF+, respectively.

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

Structure, stability and intramolecular interaction of M(N5)2(M = Mg, Ca, Sr and Ba) : a theoretical study

RSC Advances ◽  
2015 ◽  
Vol 5 (28) ◽  
pp. 21823-21830 ◽  
Author(s):  
Xueli Zhang ◽  
Junqing Yang ◽  
Ming Lu ◽  
Xuedong Gong
Keyword(s):  
Energetic Materials ◽  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Intramolecular Interaction ◽  
Earth Metal ◽  
Structure Stability ◽  
Alkaline Earth Metal ◽  
Functional Theory ◽  
The Density Functional Theory

The potential energetic materials, alkaline earth metal complexes of the pentazole anion (M(N5)2, M = Mg2+, Ca2+, Sr2+and Ba2+), were studied using the density functional theory.

Study of the Stability and Chemical Reactivity of a Series of Tetrazole Pyrimidine Hybrids by the Density Functional Theory Method (DFT)

2021 ◽  
Vol 37 (4) ◽  
pp. 805-812
Author(s):  
Ahissandonatien Ehouman ◽  
Adjoumanirodrigue Kouakou ◽  
Fatogoma Diarrassouba ◽  
Hakim Abdel Aziz Ouattara ◽  
Paulin Marius Niamien
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Molecular Descriptors ◽  
Chemical Reactivity ◽  
Density Functional Theory Method ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
The Stability ◽  
Global Reactivity Descriptors

Our theoretical study of stability and reactivity was carried out on six (06) molecules of a series of pyrimidine tetrazole hybrids (PTH) substituted with H, F, Cl, Br, OCH3 and CH3 atoms and groups of atoms using the density function theory (DFT). Analysis of the thermodynamic formation quantities confirmed the formation and existence of the series of molecules studied. Quantum chemical calculations at the B3LYP / 6-311G (d, p) level of theory determined molecular descriptors. Global reactivity descriptors were also determined and analyzed. Thus, the results showed that the compound PTH_1 is the most stable, and PTH_5 is the most reactive and nucleophilic. Similarly, the compound PTH_4 is the most electrophilic. The analysis of the local descriptors and the boundary molecular orbitals allowed us to identify the preferred atoms for electrophilic and nucleophilic attacks.

Theoretical study of NO3− interacting with carbon nanotube

Open Physics ◽  
2008 ◽  
Vol 6 (1) ◽  
Author(s):  
Silvete Guerini ◽  
David Azevedo ◽  
Maria Lima ◽  
Ivana Zanella ◽  
Josué Filho
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Quantum Mechanical ◽  
Mechanical Interaction ◽  
Electronic Density ◽  
Functional Theory ◽  
Consistent Field ◽  
The Density Functional Theory ◽  
Self Consistent Field ◽  
Field Form

AbstractThis paper deals with quantum mechanical interaction of no 3− with (5,5) and (8,0) swcnts. To perform this we have made an ab initio calculation based on the density functional theory. In these framework the electronic density plays a central role and it was obtained of a self-consistent field form. It was observed through binding energy that NO3− molecule interacts with each nanotube in a physisorption regime. We propose these swcnts as a potential filter device due to reasonable interaction with NO3− molecule. Besides this type of filter could be reusable, therefore after the filtering, the swcnts could be separated from NO3− molecule.

MAGNETIC MAP OF MnNi ALLOYED MONOLAYER ON Cu(001) SUBSTRATE: AB-INITIO CALCULATIONS

2010 ◽  
Vol 09 (06) ◽  
pp. 619-622
Author(s):  
BOTHINA A. HAMAD
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Magnetic Moments ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Exchange Correlation Potential ◽  
The Density Functional Theory ◽  
Correlation Potential

In this work, a theoretical study of the structural, electronic and magnetic properties are presented for Mn 0.5 Ni 0.5 alloyed overlayer adsorbed on Cu (001) surface. The calculations were performed using the density functional theory (DFT) and the exchange-correlation potential was treated by the generalized gradient approximation (GGA). The system was fully relaxed except for the central layer, which yields to outward relaxations and inward Mn and Ni surface atoms, respectively in the ferromagnetic and antiferromagnetic configurations. The in-plane ferromagnetic configuration was found to be more stable than the antiferromagnetic one by 25 meV/atom. The local magnetic moments of Mn atoms were found to be about 4 μ B , whereas those of the Ni atoms where found to be 0.46 μ B .

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