Density Functional Theory Calculations最新文献

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Theoretical Study of the Structure and Property of Ionic Liquids as Corrosion Inhibitor 离子液体缓蚀剂结构与性能的理论研究

Density Functional Theory Calculations Pub Date : 2020-06-19 DOI: 10.5772/INTECHOPEN.92768

G. Tian, Weizhong Zhou

{"title":"Theoretical Study of the Structure and Property of Ionic Liquids as Corrosion Inhibitor","authors":"G. Tian, Weizhong Zhou","doi":"10.5772/INTECHOPEN.92768","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.92768","url":null,"abstract":"Three sets of ionic liquids such as 1-alkyl-3-methylimidazole chloride [Cnmim]Cl, 1-alkyl-3-methylimidazolium acetate [Cnmim]Ac and 1-octyl-3-methylimidazole salt [Omim]Y (n = 2, 4, 6, 8, and Y = Cl, BF4, HSO4, Ac and TFO) were used as corrosion inhibitor medium for corrosion protection of carbon steel. Electronic structures and reactivity of these ionic liquids, surface energy and electronic structures of the iron surface were systematically analyzed by density functional theory. By increasing the alkyl chain length of the [Cnmim]Cl and [Cnmim]Ac systems, the lowest unoccupied molecular orbital energy (ELUMO), the highest occupied molecular orbital energy (EHOMO), the softness (S) and polarizability (α) increased gradually, whereas electronegativity (χ), energy gap (ΔE), hardness (η), dipole moment (μ)and electrophilic index (ω) gradually decreased. For the [Omim]Y system, the structure parameters of ionic liquids are quite different, and only the polarizability (α) decreases gradually by increasing the length of the alkyl chain. The results show that inhibition is mainly [Cnmim]+ cations of the [Cnmim]Cl system, and the order of inhibition efficiency follows as [C2mim]Cl < [C4mim]Cl < [C6mim]Cl < [C8mim]Cl. Both [Cnmim]+ cations and the Ac− anion have inhibition effect for the [Xmim]Ac system, and the order of inhibition efficiency is [C8mim]Ac > [C6mim]Ac > [C4mim]Ac > [C2mim]Ac. For the [Omim]Y system, [Xmim]+ cations and anions (BF4−, HSO4−, Ac−, TfO−) have inhibition effect, and the order of inhibition efficiency is [Omim]TfO > [Omim]Ac > [Omim]HSO4 > [Omim]BF4 > [Omim]Cl.","PeriodicalId":403695,"journal":{"name":"Density Functional Theory Calculations","volume":"74 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120873645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Quantum Computational Chemistry: Modeling and Calculation of S-Block Metal Ion Complexes 量子计算化学:s -嵌段金属离子配合物的建模与计算

Density Functional Theory Calculations Pub Date : 2020-03-11 DOI: 10.5772/INTECHOPEN.90531

Rakesh Kumar, S. Obrai

{"title":"Quantum Computational Chemistry: Modeling and Calculation of S-Block Metal Ion Complexes","authors":"Rakesh Kumar, S. Obrai","doi":"10.5772/INTECHOPEN.90531","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.90531","url":null,"abstract":"The computational study of some s-block metal nitrophenolate complexes, [Ca(THEEN)(PIC)]+ (1), [Ca(THPEN)(H2O)2]2+ (2), Ba(THPEN)(PIC)2 (3) [Na(THPEN)]22+ (4), [Sr(THPEN)(H2O)2]22+ (5) and [Ba(THPEN)(H2O)2]22+ (6) (where THEEN (N,N,N′,N′-Tetrakis(2-hydroxyethyl)ethylenediamine) and THPEN (N,N,N′,N′-Tetrakis(2-hydroxypropyl)ethylenediamine) are tetrapodal ligands and PIC− is 2,4,6-trinitrophenolate anion), is presented here using density functional theory (DFT) in its hybrid form B3LYP. The geometries of the title complexes are described by the quantum-chemical approach using input coordinates obtained from the previously synthesized and X-ray characterized diffraction data of [Ca(THEEN)(PIC)](PIC), [Ca(THPEN)(H2O)2](PIC)2, Ba(THPEN)(PIC)2, [Na(THPEN)]2(PIC)2, [Sr(THPEN)(H2O)2]2(DNP)4 and [Ba(THPEN)(H2O)2]2(DNP)4 (where DNP is 3,5-dinitrophenolate). Only the primary coordination sphere of complexes (1–6) is optimized in the gaseous phase. Calculations of the energy gaps of frontier orbitals (HOMO-LUMO), 13C-NMR shifts and vibrational bands are carried out using B3LYP/6-31 g + (d,p)/LANL2DZ level of theory. The calculated geometric and spectral parameters reproduced the experimental data with a well agreement.","PeriodicalId":403695,"journal":{"name":"Density Functional Theory Calculations","volume":"55 5","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120844215","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Conceptual DFT as a Helpful Chemoinformatics Tool for the Study of the Clavanin Family of Antimicrobial Marine Peptides 概念DFT作为海洋抗菌肽Clavanin家族的化学信息学研究工具

Density Functional Theory Calculations Pub Date : 2019-08-14 DOI: 10.5772/INTECHOPEN.88657

N. Flores-Holguín, J. Frau, D. Glossman-Mitnik

引用次数: 20