The efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. D...The efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. Dispersion-corrected DFT (DFT-D3) and time-dependent DFT (TD-DFT) calculations were performed at PBE0/def2-TZVP//PBEh-3c and CAM-B3LYP/def2- TZVP levels of theory, respectively. Conceptual DFT, the quantum theory of atoms-in-molecules (QTAIM) and local energy decomposition (LED) analyses have been performed. The LED analysis was performed at the coupled-cluster singles and doubles with perturbative triples (CCSD(T))/def2-SVP level of theory. Frontier molecular orbital energy gaps calculated using the TD-DFT method are found to lie in the range 3.574 - 4.444 eV, indicative of good adsorption and corrosion inhibition efficacies of the investigated molecules. The interactions between aluminium and the inhibitor molecules studied are found to be energetically favorable, owing to negative computed interaction energy values. Furthermore, QTAIM analysis revealed metal-carbon, metal-oxygen and metal-nitrogen interactions in the inhibitor-aluminium complexes, which are predominantly electrostatic in character, according to LED analysis results. Calculated proton affinities (PAs) have revealed the anticorrosion potentials of the investigated inhibitors in acidic medium, with a noticeable dependency on temperature within the range 273.15 - 343.15 K.展开更多
The interactions of complexes of XeOF_(2) and XeO_(3) with a series of different hybridization N-containing donors are studied by means of DFT and MP_(2) calculations.The aerogen bonding interaction energies range fro...The interactions of complexes of XeOF_(2) and XeO_(3) with a series of different hybridization N-containing donors are studied by means of DFT and MP_(2) calculations.The aerogen bonding interaction energies range from 6.5 kcal/mol to19.9 kcal/mol between XeO_(3) or XeOF_(2) and typical N-containing donors.The sequence of interaction for N-containing hy-bridization is sp^(3)>sp^(2)>sp,and XeO_(3)is higher than XeOF_(2).For some donors of sp^(2)and sp^(3) hybridization,the steric effect plays a minor role in the interaction with the evidence of reduced density gradient plots.The dominant stable part is the electrostatic interaction.In complex of XeO_(3),the weight of polarization is larger than dispersion,while the situation is opposite for XeOF_(2)complexes.Except for the sum of the maximum value of molecular electrostatic potential on Xe atom and minimum value of molecular electrostatic potential on N atom,the other five interaction parameters including the potential energy density at bond critical point,the equilibrium distances,interaction energies with the basis set superposition error correction,localized molecular orbital energy decomposition analysis interaction energies,and the electron charge density,show great linear correlation coefficients with each other.展开更多
The energies, geometries and harmonic vibrational frequencies of 1 ： 1 5-hydroxytryptamine-water （5-HT-H20） complexes are studied at the MP2/6-311 ＋ ＋ G（d,p） level. Natural bond orbital （NBO）, quantum theory ...The energies, geometries and harmonic vibrational frequencies of 1 ： 1 5-hydroxytryptamine-water （5-HT-H20） complexes are studied at the MP2/6-311 ＋ ＋ G（d,p） level. Natural bond orbital （NBO）, quantum theory of atoms in molecules （QTAIM） analyses and the localized molecular orbital energy decomposition analysis （LMO-EDA） were performed to explore the nature of the hydrogen-bonding interactions in these complexes. Various types of hydro- gen bonds （H-bonds） are formed in these 5-HT-H20 complexes. The intermolecular C4H55HT＇＂Ow H-bond in HTW3 is strengthened due to the cooperativity, whereas no such cooperativity is found in the other 5-HT-H20 complexes. H-bond in which nitrogen atom of amino in 5-HT acted as proton donors was stronger than other H-bonds. Our researches show that the hydrogen bonding interaction plays a vital role on the relative stabilities of 5-HT-H20 complexes.展开更多
文摘The efficacy and mode of action of five chalcone-based imidazole derivatives as corrosion inhibitors of aluminium metal in gas-phase and acidic medium have been investigated herein via quantum chemical calculations. Dispersion-corrected DFT (DFT-D3) and time-dependent DFT (TD-DFT) calculations were performed at PBE0/def2-TZVP//PBEh-3c and CAM-B3LYP/def2- TZVP levels of theory, respectively. Conceptual DFT, the quantum theory of atoms-in-molecules (QTAIM) and local energy decomposition (LED) analyses have been performed. The LED analysis was performed at the coupled-cluster singles and doubles with perturbative triples (CCSD(T))/def2-SVP level of theory. Frontier molecular orbital energy gaps calculated using the TD-DFT method are found to lie in the range 3.574 - 4.444 eV, indicative of good adsorption and corrosion inhibition efficacies of the investigated molecules. The interactions between aluminium and the inhibitor molecules studied are found to be energetically favorable, owing to negative computed interaction energy values. Furthermore, QTAIM analysis revealed metal-carbon, metal-oxygen and metal-nitrogen interactions in the inhibitor-aluminium complexes, which are predominantly electrostatic in character, according to LED analysis results. Calculated proton affinities (PAs) have revealed the anticorrosion potentials of the investigated inhibitors in acidic medium, with a noticeable dependency on temperature within the range 273.15 - 343.15 K.
基金financially supported by the China Postdoctoral Science Foundation(No.2020M682154)。
文摘The interactions of complexes of XeOF_(2) and XeO_(3) with a series of different hybridization N-containing donors are studied by means of DFT and MP_(2) calculations.The aerogen bonding interaction energies range from 6.5 kcal/mol to19.9 kcal/mol between XeO_(3) or XeOF_(2) and typical N-containing donors.The sequence of interaction for N-containing hy-bridization is sp^(3)>sp^(2)>sp,and XeO_(3)is higher than XeOF_(2).For some donors of sp^(2)and sp^(3) hybridization,the steric effect plays a minor role in the interaction with the evidence of reduced density gradient plots.The dominant stable part is the electrostatic interaction.In complex of XeO_(3),the weight of polarization is larger than dispersion,while the situation is opposite for XeOF_(2)complexes.Except for the sum of the maximum value of molecular electrostatic potential on Xe atom and minimum value of molecular electrostatic potential on N atom,the other five interaction parameters including the potential energy density at bond critical point,the equilibrium distances,interaction energies with the basis set superposition error correction,localized molecular orbital energy decomposition analysis interaction energies,and the electron charge density,show great linear correlation coefficients with each other.
文摘The energies, geometries and harmonic vibrational frequencies of 1 ： 1 5-hydroxytryptamine-water （5-HT-H20） complexes are studied at the MP2/6-311 ＋ ＋ G（d,p） level. Natural bond orbital （NBO）, quantum theory of atoms in molecules （QTAIM） analyses and the localized molecular orbital energy decomposition analysis （LMO-EDA） were performed to explore the nature of the hydrogen-bonding interactions in these complexes. Various types of hydro- gen bonds （H-bonds） are formed in these 5-HT-H20 complexes. The intermolecular C4H55HT＇＂Ow H-bond in HTW3 is strengthened due to the cooperativity, whereas no such cooperativity is found in the other 5-HT-H20 complexes. H-bond in which nitrogen atom of amino in 5-HT acted as proton donors was stronger than other H-bonds. Our researches show that the hydrogen bonding interaction plays a vital role on the relative stabilities of 5-HT-H20 complexes.
