Comparison of the selectivity of [M(12-Crown-4)]+ (M=Li+, Na+, K+) complexes for halide anions and some neutral molecules; a computational study

2015 ◽  
Vol 14 (08) ◽  
pp. 1550057 ◽  
Author(s):  
Faranak Dastineh ◽  
Sadegh Salehzadeh ◽  
Mehdi Bayat ◽  
Yazdan Maghsoud
Keyword(s):  
Interaction Energy ◽  
Gas Phase ◽  
High Selectivity ◽  
Theoretical Study ◽  
Computational Study ◽  
Decomposition Analysis ◽  
Interaction Energies ◽  
Halide Anions ◽  
Bonding Interaction ◽  
M 12

A theoretical study on the selectivity of a series of [M(12C4)][Formula: see text] (M = Li[Formula: see text], Na[Formula: see text], K[Formula: see text], 12C4 = 12-crown-4) complexes for F[Formula: see text], Cl[Formula: see text] and Br[Formula: see text] anions and a number of neutral molecules (CH3CN, CH3OH, NH3, H2O, py, and 12C4) is reported. At first, it was shown that in the gas phase among all studied halide anions and neutral molecules, halides have much more bonding interaction with all [M(12C4)][Formula: see text] cations. Calculated interaction energies of above anions and [M(12C4)][Formula: see text] cations decrease from F[Formula: see text] to Br[Formula: see text]. Also the interaction energy of halide anions with [M(12C4)][Formula: see text] complexes, decreases from [Li(12C4)][Formula: see text] to [K(12C4)][Formula: see text]. The electron decomposition analysis showed that the bond between [M(12C4)][Formula: see text] complexes and both the neutral and anion guests is mainly electrostatic in nature. Then the selectivity of [M(12C4)][Formula: see text] complexes for studied anions and neutral molecules are compared in methanol, acetone, acetonitrile, and nitromethane solutions. It was shown that both the desolvation process of reactants and the strength of host–guest interactions have significant effect on the selectivities. Thus the selectivity of [Li(12C4)][Formula: see text] cation for NH3and H2O neutral molecules in solution, in contrast to the gas phase, is higher than that for bromide anion. The results of calculations showed that all [M(12C4)][Formula: see text] complexes, specially [Li(12C4)][Formula: see text], have high selectivity for F[Formula: see text] over other halide anions and neutral molecules.

scholarly journals Gas Phase Computational Study of Diclofenac Adsorption on Chitosan Materials

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2549
Author(s):  
Anna Kaczmarek-Kędziera
Keyword(s):  
Interaction Energy ◽  
Gas Phase ◽  
Computational Study ◽  
Intramolecular Interactions ◽  
Amino Groups ◽  
Inflammatory Drugs ◽  
Low Costs ◽  
Anti Inflammatory ◽  
Single Polymer Chain ◽  
Living Organisms

Environmental pollution with non-steroidal anti-inflammatory drugs and their metabolites exposes living organisms on their long-lasting, damaging influence. Hence, the ways of non-steroidal anti-inflammatory drugs (NSAIDs) removal from soils and wastewater is sought for. Among the potential adsorbents, biopolymers are employed for their good availability, biodegradability and low costs. The first available theoretical modeling study of the interactions of diclofenac with models of pristine chitosan and its modified chains is presented here. Supermolecular interaction energy in chitosan:drug complexes is compared with the the mutual attraction of the chitosan dimers. Supermolecular interaction energy for the chitosan-diclofenac complexes is significantly lower than the mutual interaction between two chitosan chains, suggesting that the diclofenac molecule will encounter problems when penetrating into the chitosan material. However, its surface adsorption is feasible due to a large number of hydrogen bond donors and acceptors both in biopolymer and in diclofenac. Modification of chitosan material introducing long-distanced amino groups significantly influences the intramolecular interactions within a single polymer chain, thus blocking the access of diclofenac to the biopolymer backbone. The strongest attraction between two chitosan chains with two long-distanced amino groups can exceed 120 kcal/mol, while the modified chitosan:diclofenac interaction remains of the order of 20 to 40 kcal/mol.

scholarly journals Theoretical Study about the Effect of Halogen Substitution on the Reactivity of Antitumor 3-Formylchromones and Their Free Radicals

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Maximiliano Martínez-Cifuentes ◽  
Boris Weiss-López ◽  
Ramiro Araya-Maturana
Keyword(s):  
Free Radicals ◽  
Hydrogen Atom ◽  
Gas Phase ◽  
Theoretical Study ◽  
Computational Study ◽  
Bond Dissociation Enthalpy ◽  
Radical Species ◽  
Anticancer Compounds ◽  
Dissociation Enthalpy ◽  
Polarizable Continuum

The mandatory presence of a chlorine atom on the aromatic ring of 6-hydroxy-3-formyl angular chromones, on the respiration inhibition of mammary carcinoma mouse, is explained through a computational study of these compounds. This study analyzes the reactivity of the neutral molecules and their free radicals, in gas phase and with water solvation, incorporated by the polarizable continuum medium (PCM) approach. Electrophilic reactivities were evaluated using Fukui (f+) and Parr (P+) functions. The stabilities of radical species formed by the abstraction of a hydrogen atom from the O-H bond were evaluated by bond dissociation enthalpy (BDE) and spin density (SD) calculations. This study has potential implications for the design of chromone analogues as anticancer compounds.

scholarly journals Theoretical Study on the Extraction of Alkaline Earth Salts by 18-Crown-6: Roles of Counterions, Solvent Types and Extraction Temperatures

2014 ◽  
Vol 14 (2) ◽  
pp. 199-208 ◽  
Author(s):  
Saprizal Hadisaputra ◽  
Lorenz R Canaval ◽  
Harno Dwi Pranowo ◽  
Ria Armunanto
Keyword(s):  
Gas Phase ◽  
Density Functional ◽  
Alkaline Earth ◽  
Theoretical Study ◽  
Polar Solvent ◽  
Density Functional Method ◽  
Nitrate Anion ◽  
Interaction Energies ◽  
Free Energies ◽  
Solvent Phase

The roles of counterions, solvent types and extraction temperatures on the selectivity of 18-crown-6 (L) toward alkaline earth salts MX2 (M = Ca, Sr, Ba; X = Cl-, NO3-) have been studied by density functional method at B3LYP level of theory in gas and solvent phase. In gas phase, the chloride anion Cl- is the preference counterion than nitrate anion NO3-. This result is confirmed by the interaction energies, the second order interaction energies, charge transfers, energy difference between HOMO-LUMO and electrostatic potential maps. The presence of solvent reversed the gas phase trend. It is found that NO3- is the preference counterion in solvent phase. The calculated free energies demonstrate that the solvent types strongly change the strength of the complex formation. The free energies are exothermic in polar solvent while for the non polar solvent the free energies are endothermic. As the temperature changes the free energies also vary where the higher the temperatures the lower the free energy values. The calculated free energies are correlated well with the experimental stability constants. This theoretical study would have a strong contribution in planning the experimental conditions in terms of the preference counterions, solvent types and optimum extraction temperatures.

scholarly journals A theoretical study of the neutral and the double-charged cation of cyclo[8]pyrrole and its interaction with inorganic anions

2009 ◽  
Vol 7 (4) ◽  
pp. 683-689 ◽  
Author(s):  
Ibon Alkorta ◽  
Fernando Blanco ◽  
José Elguero
Keyword(s):  
Gas Phase ◽  
Theoretical Study ◽  
Interaction Energies ◽  
Neutral Form ◽  
Opposite Charge ◽  
Water Solvent ◽  
Solvent Model ◽  
The Individual ◽  
Computational Level ◽  
Large Interaction

AbstractA theoretical study of the complexation of cyclo[8]pyrrole dication, 2, and the corresponding system in neutral form, 3, with six anionic molecules has been carried out up to the B3LYP/6–311++G(2d,2p) computational level. The effect of the water solvation has been taken into account by means of the PCM method. The gas phase results correspond to the very large interaction energies expected for the interaction of molecules of opposite charge. In all the complexes, the analysis of the electron density by means of the Atoms In Molecules (AIM) methodology shows the presence of eight intermolecular interactions between the individual molecules. The results, using the water solvent model, indicate that the 2:SO42− complex is more stable than the 2:NO3−, in agreement with experimental results.

scholarly journals THEORETICAL STUDY ON 15-CROWN-5 COMPLEX WITH SOME METAL CATIONS

2012 ◽  
Vol 12 (2) ◽  
pp. 135-140 ◽  
Author(s):  
Yahmin Yahmin ◽  
Harno Dwi Pranowo ◽  
Ria Armunanto
Keyword(s):  
Gas Phase ◽  
Metal Binding ◽  
Theoretical Study ◽  
Metal Cations ◽  
Quantum Mechanical ◽  
Interaction Energies ◽  
Mechanical Method ◽  
Binding Properties ◽  
Quantum Mechanical Method ◽  
Binding Capability

The capability of 15-crown-5 ethers to form complexes with some metal cations (Li+, Na+, K+, Zn2+, Cd2+ and Hg2+) was investigated by an ab initio quantum mechanical method. The calculations were performed at the RHF/lanl2mb level of theory. The interaction energies were used to evaluate the metal binding capability of the crown ether. The effect of nature of the metal on the binding properties was also studied. The results of the calculations showed that the interaction energy of the complexes increased in proportion with the ratio of ion charge, electronegativity and ionization potential to the cation diameter. In addition, based on the extraction distribution coefficient in the gas phase, it is found that the 15-crown-5 could not extract metal cations investigated.

scholarly journals 3,3-Bis(2-hydroxyethyl)-1-(4-methylbenzoyl)thiourea: crystal structure, Hirshfeld surface analysis and computational study

2019 ◽  
Vol 75 (10) ◽  
pp. 1472-1478 ◽  
Author(s):  
Sang Loon Tan ◽  
Ainnul Hamidah Syahadah Azizan ◽  
Mukesh M. Jotani ◽  
Edward R. T. Tiekink
Keyword(s):  
Hydrogen Bonds ◽  
Gas Phase ◽  
Computational Study ◽  
Supramolecular Interactions ◽  
Interaction Energies ◽  
Dft Methods ◽  
Covalent Interaction ◽  
Hirshfeld Surfaces ◽  
First Approximation ◽  
Hydroxyethyl Group

In the title tri-substituted thiourea derivative, C13H18N2O3S, the thione-S and carbonyl-O atoms lie, to a first approximation, to the same side of the molecule [the S—C—N—C torsion angle is −49.3 (2)°]. The CN2S plane is almost planar (r.m.s. deviation = 0.018 Å) with the hydroxyethyl groups lying to either side of this plane. One hydroxyethyl group is orientated towards the thioamide functionality enabling the formation of an intramolecular N—H...O hydrogen bond leading to an S(7) loop. The dihedral angle [72.12 (9)°] between the planes through the CN2S atoms and the 4-tolyl ring indicates the molecule is twisted. The experimental molecular structure is close to the gas-phase, geometry-optimized structure calculated by DFT methods. In the molecular packing, hydroxyl-O—H...O(hydroxyl) and hydroxyl-O—H...S(thione) hydrogen bonds lead to the formation of a supramolecular layer in the ab plane; no directional interactions are found between layers. The influence of the specified supramolecular interactions is apparent in the calculated Hirshfeld surfaces and these are shown to be attractive in non-covalent interaction plots; the interaction energies point to the important stabilization provided by directional O—H...O hydrogen bonds.

Theoretical investigation of gas-phase molecular complex formation between 2-hydroxy thiophenol and a water molecule

2017 ◽  
Vol 19 (3) ◽  
pp. 2466-2478 ◽  
Author(s):  
Debojit Kumar Deb ◽  
Biplab Sarkar
Keyword(s):  
Hydrogen Bonding ◽  
Complex Formation ◽  
Water Molecule ◽  
Gas Phase ◽  
Systematic Study ◽  
Molecular Complex ◽  
Interaction Energies ◽  
Hydrogen Bonding Interaction ◽  
Molecular Complex Formation ◽  
Bonding Interaction

A systematic study of the interaction energies and hydrogen bonding interaction of a gas-phase molecular complex between 2-hydroxy thiophenol and a water molecule.

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