1
|
Liu X, Feng H, Li R, Zhang Q, Wu Y, Pang B. Mechanistic Insights into the Proton Transfer and Substitution Dynamics of N-Atom Center Reactions: A Study of CH 3O - with NH 2Cl. J Phys Chem A 2024. [PMID: 38502933 DOI: 10.1021/acs.jpca.3c08447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Bimolecular substitution reactions involving N as the central atom have continuously improved our understanding of substitution dynamics. This work used chemical dynamics simulations to investigate the dynamics of NH2Cl with N as the central atom and the multiatomic nucleophile CH3O- and compared these results with the F- + NH2Cl reaction. The most noteworthy difference is in the competition between proton transfer (PT) and the SN2 pathways. Our results demonstrate that, for the CH3O- + NH2Cl system, the PT pathway is considerably more favorable than the SN2 pathway. In contrast, no PT pathway was observed for the F- + NH2Cl system at room temperature. This can be attributed to the exothermic reaction of the PT pathway for the CH3O- + NH2Cl reaction and is coupled with a more stable transition state compared to the substitution pathway. Furthermore, the bulky nature of the CH3O- group impedes its participation in SN2 reactions, which enhances both the thermodynamic and the dynamic advantages of the PT reaction. Interestingly, the atomic mechanism reveals that the PT pathway is primarily governed by indirect mechanisms, similar to the SN2 pathway, with trajectories commonly trapped in the entrance channel being a prominent feature. These trajectories are often accompanied by prolonged and frequent proton exchange or proton abstraction processes. This current work provides insights into the dynamics of N-centered PT reactions, which are useful in gaining a comprehensive understanding of the dynamics behavior of similar reactions.
Collapse
Affiliation(s)
- Xu Liu
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Huining Feng
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Rui Li
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Qiuju Zhang
- Key Laboratory of Advanced Fuel Cells and Electrolyzers Technology of Zhejiang Province, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, China
| | - Yang Wu
- College of Chemistry, Liaoning University, Shenyang 110036, P. R. China
| | - Boxue Pang
- Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines, School of Resources and Civil Engineering, Northeastern University, Shenyang 110819, China
| |
Collapse
|
2
|
Mahmood A, Akram T, Chen S, Azam S. From Molecules to Devices: Insights into Electronic and Optical Properties of Pyridine-Derived Compounds Using Density Functional Theory Calculations. J Phys Chem A 2024; 128:1049-1062. [PMID: 38323545 DOI: 10.1021/acs.jpca.3c07585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2024]
Abstract
In this study, we delve into the electronic structure, spectroscopic, and optical properties of five benzo derivatives of pyridine, namely, 5-(4-chlorophenyl)-2-fluoropyridine (1), 2-fluoro-5-(4-fluorophenyl)pyridine (2), 4-(2-fluoropyridin-5-yl)phenol (3), 5-(2,3-dichlorophenyl)-2-fluoropyridine (4), and 5-(5-bromo-2-methoxyphenyl)-2-fluoropyridine (5). Utilizing quantum chemical density functional theory calculations at the B3LYP and Perdew-Burke-Ernzerhof levels of theory combined with the 6-311G(d,p) and 6-311++G(d,p) basis sets, we investigated the electronic and optical characteristics of these compounds. Band structure calculations were conducted for their crystalline structures, revealing a direct band gap varying from 3.018 to 3.558 eV, with the valence band maximum and conduction band minimum located at the G point in the Brillouin zone. The optical properties were analyzed, including the dielectric functions, reflectivity, and refractive index. Notably, reflectivity was found to be minimal in the photon energy range of 0.0-3.0 eV, and the static refractive index, n(0), ranged from 1.55 to 1.70. The research also involved assessing the reactivity of the compounds through calculation of the frontier orbital energy gaps (ΔE), indicating a significant charge transfer and high reactivity. Additionally, we performed frequency analysis to unveil the Fourier-transform infrared spectra of compounds 1-5 at room temperature. Molecular electrostatic potential surfaces of the optimized structures were employed to map the electrophilic and nucleophilic regions of the compounds. This investigation provides a comprehensive understanding of the electronic and optical properties of these pyridine derivatives, shedding light on their potential applications in optoelectronics.
Collapse
Affiliation(s)
- Ayyaz Mahmood
- School of Mechanical Engineering, Dongguan University of Technology, Dongguan 523808, China
- School of Life Science and Technology, University of Electronic Science and Technology, Chengdu 610054, China
- School of Art and Design, Guangzhou Panyu Polytechnic, Guangzhou 511483, China
| | - Tayyaba Akram
- Department of Physics, COMSATS Institute of Information Technology, Lahore 54000, Pakistan
| | - Shenggui Chen
- School of Mechanical Engineering, Dongguan University of Technology, Dongguan 523808, China
- School of Art and Design, Guangzhou Panyu Polytechnic, Guangzhou 511483, China
| | - Sikander Azam
- New Technologies─Research Center, University of West Bohemia, Univerzitni 8, 306 14 Pilsen, Czech Republic
| |
Collapse
|
3
|
Mahmood A, Perveen F, Akram T, Chen S, Irfan A, Chen H. Advancing nitrate reduction to ammonia: insights into mechanism, activity control, and catalyst design over Pt nanoparticle-based ZrO 2. RSC Adv 2023; 13:34497-34509. [PMID: 38024971 PMCID: PMC10667968 DOI: 10.1039/d3ra06449b] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Accepted: 11/10/2023] [Indexed: 12/01/2023] Open
Abstract
The reduction of nitrogen oxides (NOx) to NH3, or N2 represents a crucial step in mitigating atmospheric NO3 and NO2 emissions, a significant contributor to air pollution. Among these reduction products, ammonia (NH3) holds particular significance due to its utility in nitrogen-based fertilizers and its versatile applications in various industrial processes. Platinum-based catalysts have exhibited promise in enhancing the rate and selectivity of these reduction reactions. In this study, we employ density functional theory (DFT) calculations to explore the catalytic potential of Pt nanoparticle (PtNP)-supported ZrO2 for the conversion of NO3 to NH3. The most favorable pathway for the NO3 reduction to NH3 follows a sequence, that is, NO3 → NO2 → NO → ONH → ONH2/HNOH → NH2/NH → NH2 → NH3, culminating in the production of valuable ammonia. The introduction of low-state Fe and Co dopants into the ZrO2 support reduces energy barriers for the most challenging rate-determining hydrogenation step in NOx reduction to NH3, demonstrating significant improvements in catalytic activity. The incorporation of dopants into the ZrO2 support results in a depletion of electron density within the Pt cocatalyst resulting in enhanced hydrogen transfer efficiency during the hydrogenation process. This study aims to provide insights into the catalytic activity of platinum-based ZrO2 catalysts and will help design new high-performance catalysts for the reduction of atmospheric pollutants and for energy applications.
Collapse
Affiliation(s)
- Ayyaz Mahmood
- School of Life Science and Technology, University of Electronic Science and Technology Chengdu 610054 China
- School of Mechanical Engineering, Dongguan University of Technology Dongguan 523808 China
- School of Art and Design, Guangzhou Panyu Polytechnic Guangzhou 511483 China
- Dongguan Institute of Science and Technology Innovation, Dongguan University of Technology Dongguan 523808 China
| | - Fouzia Perveen
- School of Interdisciplinary Engineering & Sciences (SINES), National University of Sciences and Technology (NUST) Sector H-12 Islamabad 44000 Pakistan
| | - Tehmina Akram
- CAS Key Laboratory of Soft Matter Chemistry, Hefei National Laboratory for Physical Sciences at Microscale, Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Chemistry, University of Science and Technology of China Hefei 230026 China
| | - Shenggui Chen
- School of Mechanical Engineering, Dongguan University of Technology Dongguan 523808 China
- School of Art and Design, Guangzhou Panyu Polytechnic Guangzhou 511483 China
- Dongguan Institute of Science and Technology Innovation, Dongguan University of Technology Dongguan 523808 China
| | - Ahmad Irfan
- Department of Chemistry, College of Science, King Khalid University P.O. Box 9004 Abha 61413 Saudi Arabia
| | - Huafu Chen
- School of Life Science and Technology, University of Electronic Science and Technology Chengdu 610054 China
| |
Collapse
|
4
|
Tachikawa H. Reaction mechanism of an intracluster S N2 reaction induced by electron capture. Phys Chem Chem Phys 2022; 24:3941-3950. [PMID: 35098286 DOI: 10.1039/d1cp04697g] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bimolecular nucleophilic substitution (SN2) reactions have been widely investigated from both experimental and theoretical points of view because they represent one of the simplest organic reactions. Most studies on SN2 reactions have been focused on bimolecular collision. In contrast, information on intracluster SN2 reactions is limited. In this study, an intracluster SN2 reaction of NF3-CH3Cl triggered by electron attachment was investigated using a direct ab initio molecular dynamics (AIMD) method. In the structure of NF3-CH3Cl, the N-F bond in NF3 is oriented collinearly toward the carbon atom of CH3Cl. After electron capture by NF3-CH3Cl, the F- ion that is generated from the (NF3)- moiety collides with the carbon atom of CH3Cl. The intracluster SN2 reaction occurs as follows: (NF3-CH3Cl)- (electron capture state) → NF2-(F-)-CH3Cl (pre-reaction complex) → transition state (TS) → NF2-CH3F-Cl- (post-reaction complex) → NF2 + CH3F + Cl- (product state). The reaction energy is efficiently transferred to the translational mode of Cl-, and the Cl- ion with a high translational energy is then removed from the system. This energy is significantly larger than that of Cl- formed in the bimolecular SN2 reaction (F- + CH3Cl). The reaction mechanism is discussed based on the theoretical results.
Collapse
Affiliation(s)
- Hiroto Tachikawa
- Division of Applied Chemistry, Faculty of Engineering, Hokkaido University, Sapporo 060-8628, Japan.
| |
Collapse
|
5
|
Mahmood A, Akram T, Kiani M, Akram T, Tian X, Sun Y. Mechanism and Regioselectivity in Methylation of Nitronates [CH2NO2]−: Resonance vs Inductive Effects. NEW J CHEM 2022. [DOI: 10.1039/d2nj02947b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory calculations were performed to investigate the mechanism, regioselectivity, and the resonance and inductive effects in methylation of nitronate reactions in the gas-phase and in solutions (water, DMF,...
Collapse
|
6
|
Hamlin TA, Swart M, Bickelhaupt FM. Nucleophilic Substitution (S N 2): Dependence on Nucleophile, Leaving Group, Central Atom, Substituents, and Solvent. Chemphyschem 2018; 19:1315-1330. [PMID: 29542853 PMCID: PMC6001448 DOI: 10.1002/cphc.201701363] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Indexed: 11/12/2022]
Abstract
The reaction potential energy surface (PES), and thus the mechanism of bimolecular nucleophilic substitution (SN 2), depends profoundly on the nature of the nucleophile and leaving group, but also on the central, electrophilic atom, its substituents, as well as on the medium in which the reaction takes place. Here, we provide an overview of recent studies and demonstrate how changes in any one of the aforementioned factors affect the SN 2 mechanism. One of the most striking effects is the transition from a double-well to a single-well PES when the central atom is changed from a second-period (e. g. carbon) to a higher-period element (e.g, silicon, germanium). Variations in nucleophilicity, leaving group ability, and bulky substituents around a second-row element central atom can then be exploited to change the single-well PES back into a double-well. Reversely, these variations can also be used to produce a single-well PES for second-period elements, for example, a stable pentavalent carbon species.
Collapse
Affiliation(s)
- Trevor A. Hamlin
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
| | - Marcel Swart
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institut de Química Computacional I Catàlisi and Department de QuímicaUniversitat de Girona17003GironaSpain
- ICREAPg. Lluís Companys 2308010BarcelonaSpain
| | - F. Matthias Bickelhaupt
- Department of Theoretical Chemistry andAmsterdam Center for Multiscale Modeling (ACMM)Vrije Universiteit AmsterdamDe Boelelaan 10831081 HVAmsterdamThe Netherlands
- Institute of Molecules and Materials (IMM)Radboud UniversityHeyendaalseweg 1356525 AJNijmegenThe Netherlands
| |
Collapse
|
7
|
Proenza YG, de Souza MAF, Longo RL. Dynamical Bifurcation in Gas-Phase XH - + CH 3 Y S N 2 Reactions: The Role of Energy Flow and Redistribution in Avoiding the Minimum Energy Path. Chemistry 2016; 22:16220-16229. [PMID: 27651104 DOI: 10.1002/chem.201602976] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Indexed: 11/10/2022]
Abstract
The gas-phase reactions of XH- (X=O, S) + CH3 Y (Y=F, Cl, Br) span nearly the whole range of SN 2 pathways, and show an intrinsic reaction coordinate (IRC) (minimum energy path) with a deep well owing to the CH3 XH⋅⋅⋅Y- (or CH3 S- ⋅⋅⋅HF) hydrogen-bonded postreaction complex. MP2 quasiclassical-type direct dynamics starting at the [HX⋅⋅⋅CH3 ⋅⋅⋅Y]- transition-state (TS) structure reveal distinct mechanistic behaviors. Trajectories that yield the separated CH3 XH+Y- (or CH3 S- +HF) products directly are non-IRC, whereas those that sample the CH3 XH⋅⋅⋅Y- (or CH3 S- ⋅⋅⋅HF) complex are IRC. The IRCIRC/non-IRC ratios of 90:10, 40:60, 25:75, 2:98, 0:100, and 0:100 are obtained for (X, Y)=(S, F), (O, F), (S, Cl), (S, Br), (O, Cl), and (O, Br), respectively. The properties of the energy profiles after the TS cannot provide a rationalization of these results. Analysis of the energy flow in dynamics shows that the trajectories cross a dynamical bifurcation, and that the inability to follow the minimum energy path arises from long vibration periods of the X-C⋅⋅⋅Y bending mode. The partition of the available energy to the products into vibrational, rotational, and translational energies reveals that if the vibrational contribution is more than 80 %, non-IRC behavior dominates, unless the relative fraction of the rotational and translational components is similar, in which case a richer dynamical mechanism is shown, with an IRC/non-IRC ratio that correlates to this relative fraction.
Collapse
Affiliation(s)
- Yaicel G Proenza
- Departamento de Química Fundamental, CCEN, Universidade Federal de Pernambuco, 50.740-560, Recife, PE, Brazil
| | - Miguel A F de Souza
- Instituto de Química, CCET, Universidade Federal do Rio Grande do Norte, 59.072-970, Natal, RN, Brazil
| | - Ricardo L Longo
- Departamento de Química Fundamental, CCEN, Universidade Federal de Pernambuco, 50.740-560, Recife, PE, Brazil.
| |
Collapse
|
8
|
Mahmood A, Longo RL. Structural and relative energy assessments of DFT functionals and the MP2 method to describe the gas phase methylation of nitronates: [R1R2CNO2]− + CH3I. Phys Chem Chem Phys 2016; 18:17062-70. [DOI: 10.1039/c5cp07833d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structures and energetics of CH3I + [R1R2CNO2]− gas phase C- and O-methylation reactions were computed with several functionals and ECP/basis sets and compared to CCSD(T)/CBS.
Collapse
Affiliation(s)
- Ayyaz Mahmood
- Departamento de Química Fundamental
- CCEN
- Universidade Federal de Pernambuco
- Cidade Universitária
- Recife
| | - Ricardo L. Longo
- Departamento de Química Fundamental
- CCEN
- Universidade Federal de Pernambuco
- Cidade Universitária
- Recife
| |
Collapse
|