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Eryilmaz S, Bagdatli E. Structural characterization and keto-enol tautomerization of 4-substituted pyrazolone derivatives with DFT approach. J Mol Graph Model 2024; 131:108814. [PMID: 38968767 DOI: 10.1016/j.jmgm.2024.108814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/19/2024] [Accepted: 06/17/2024] [Indexed: 07/07/2024]
Abstract
The synthesis of two pyrazolone derivative compounds, PYR-I(4-Acetyl-1-(4-chlorophenyl)-3-isopropyl-1H-pyrazol-5(4H)-one) and PYR-II1-(4-Chlorophenyl))-3-isopropyl-5-oxo-4,5-5-dihydro-1H-pyrazole-4-carbaldehyde, their characterization by FT-IR, NMR, UV-Vis and GC-MS techniques, and the evaluation of the keto-enol tautomerization process of the structures along with the DFT approach and spectral data were reported in this paper. Spectral findings indicated that PYR-I was stable at the keto state. The IR spectrum recorded in solid form showed that the PYR-II structure was stable in the enol state, while the NMR spectrum in the solution medium showed that it was stable in the keto state. DFT-based analyses were realized with the B3LYP hybrid functional and the 6-311++G(d,p) basis set. The modelled keto, transition and enol state molecular geometries of structures were optimized in the gas phase and different solvent media and the total energy and dipole moment values were investigated at the specified theoretical level. The possible keto-enol tautomerism mechanism of the structures was evaluated through some thermodynamic parameters such as the difference in free Gibbs energy (ΔG), enthalpy (ΔH), entropy (ΔS), and predictive tautomeric equilibrium constants (Keq), acidity constants (pKa) and percentages of tautomers at 298.15 K and 1 atm pressure. The results of these analyses based on the DFT approach indicated that the keto-enol tautomer equilibrium heavily favours the keto form for PYR-I and the enol form for PYR-II in all cases. Moreover, natural bond orbital (NBO) analysis was performed for the tautomers, and the chemical reactivity profiles of the most stable tautomers were examined with the values of frontier molecular orbital energy and some reactivity descriptors.
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Affiliation(s)
- Serpil Eryilmaz
- Department of Physics, Faculty of Arts and Sciences, Amasya University, 05100, Amasya, Turkey.
| | - Emine Bagdatli
- Department of Chemistry, Faculty of Arts and Sciences, Ordu University, 52200, Ordu, Turkey
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2
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Nayak S, Rajakumar B. High-Temperature Pyrolysis Study of 2-Methyl-2-butanol behind Reflected Shock Wave: Shock Tube and Computational Study. J Phys Chem A 2024; 128:5691-5706. [PMID: 38973315 DOI: 10.1021/acs.jpca.4c01593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
Pyrolysis of a branched alcohol, 2-methyl-2-butanol (2M2BOH), was carried out behind the reflected shock wave in the temperature range of 1011-1303 K and under pressures varying from 9.3 to 14.6 atm. Qualitative and quantitative analysis of the postshock mixture was performed using gas chromatography-mass spectrometry and gas chromatography with a flame ionization detector, respectively. The rate coefficients for the C-C and C-O bond cleavage reaction pathways were calculated using the variational transition-state theory. The Rice-Ramsperger-Kessel-Marcus/Master equation was employed to calculate the rate coefficients for the H2O-elimination reactions, unimolecular dissociation, and isomerization reaction pathways. The overall decomposition rate coefficient for the 2-methyl 2-butanol (2M2BOH) was estimated to be k t o t a l e x p t ( 1011 - 1303 K ) = ( 3.29 ± 0.73 ) × 10 11 × exp [ - ( 47.41 ± 0.53 T ) ] s - 1 , where activation energy is given in kcal mol-1. The reaction path analysis was performed, which gives information regarding the contribution of individual intermediate species toward the decomposition of 2M2BOH. A set of reactions was proposed and used to simulate the combustion chemistry of 2M2BOH, which consists of 48 reactions and 39 species. The experimentally measured and simulated mole fractions for the reactant and products showed reasonably good agreement. This work additionally investigates the effect of branching on the decomposition kinetics of long-chain alcohols.
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Affiliation(s)
- Subhadarsi Nayak
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
| | - Balla Rajakumar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India
- Centre for Atmospheric and Climate Sciences, Indian Institute of Technology Madras, Chennai 600036, India
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Mohamed SY, Monge-Palacios M, Giri BR, Khaled F, Liu D, Farooq A, Sarathy SM. The Effect of Hydrogen Bonding on the Reactivity of OH Radicals with Prenol and Isoprenol: A Shock Tube and Multi-Structural Torsional Variational Transition State Theory Study. Phys Chem Chem Phys 2022; 24:12601-12620. [DOI: 10.1039/d2cp00737a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The presence of two functional groups (OH and double bond) in C5 methyl-substituted enols (i.e., isopentenols), such as 3-methyl-2-buten-1-ol (prenol) and 3-methyl-3-buten-1-ol (isoprenol), makes them excellent biofuel candidates as fuel...
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4
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Serenko YV, Ponomarev AV, Belova EV. Direct and Indirect Effects of an Electron Beam on N,N,N',N'-Tetra-n-Octyl Diglycolamide in Hydrocarbon–Alcohol Solutions. HIGH ENERGY CHEMISTRY 2021. [DOI: 10.1134/s0018143921060114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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5
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Sakata K, Goto Y, Yoshikawa T, Nishibayashi Y. Enantioselectivity in Ruthenium-Catalyzed Propargylic Substitution Reactions of Propargylic Alcohols with Acetone: A DFT Study. Chem Asian J 2021; 16:3760-3766. [PMID: 34549529 DOI: 10.1002/asia.202100984] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 09/09/2021] [Indexed: 11/07/2022]
Abstract
The enantioselectivity in the propargylic substitution reactions of propargylic alcohols with acetone catalyzed by optically active thiolate-bridged diruthenium complexes was examined via ωB97X-D level DFT calculations. Some structures with intramolecular dispersion interactions between ligands were found for the ruthenium-allenylidene complex, which is the key intermediate in the catalytic reaction, and it was determined that the structure corresponding to the X-ray crystal structure, which had provided the transition state model for the enantioselectivity in previous studies, was not the most stable among the obtained structures. Then, a variety of transition-state structures for the nucleophilic attack of prop-1-ene-2-ol, which is the enol isomer of acetone, on the γ-carbon of the ruthenium-allenylidene complex were explored. Among the transition-state structures with lower energies, the number of structures leading to the major (R) product was found to be larger than that of structures leading to the minor (S) product, providing enantioselectivity in terms of probability distributions. The introduction of a phenyl group in the thiolate ligand was suggested to increase the selectivity. Thus, we propose the novel transition state model for the asymmetric catalytic reaction system.
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Affiliation(s)
- Ken Sakata
- Faculty of Pharmaceutical Sciences, Toho University, Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Yui Goto
- Faculty of Pharmaceutical Sciences, Toho University, Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Takeshi Yoshikawa
- Faculty of Pharmaceutical Sciences, Toho University, Miyama, Funabashi, Chiba, 274-8510, Japan
| | - Yoshiaki Nishibayashi
- Department of Applied Chemistry, School of Engineering, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
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6
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Vlasov S, Ponomarev A. Signs of keto-enol tautomerism in acetone radiolysis. Radiat Phys Chem Oxf Engl 1993 2021. [DOI: 10.1016/j.radphyschem.2021.109460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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7
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Imatdinova DN, Vlasov SI, Ponomarev AV. Enolization in the radiolysis of acetone. MENDELEEV COMMUNICATIONS 2021. [DOI: 10.1016/j.mencom.2021.07.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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8
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Zaleski DP, Sivaramakrishnan R, Weller HR, Seifert NA, Bross DH, Ruscic B, Moore KB, Elliott SN, Copan AV, Harding LB, Klippenstein SJ, Field RW, Prozument K. Substitution Reactions in the Pyrolysis of Acetone Revealed through a Modeling, Experiment, Theory Paradigm. J Am Chem Soc 2021; 143:3124-3142. [PMID: 33615780 DOI: 10.1021/jacs.0c11677] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The development of high-fidelity mechanisms for chemically reactive systems is a challenging process that requires the compilation of rate descriptions for a large and somewhat ill-defined set of reactions. The present unified combination of modeling, experiment, and theory provides a paradigm for improving such mechanism development efforts. Here we combine broadband rotational spectroscopy with detailed chemical modeling based on rate constants obtained from automated ab initio transition state theory-based master equation calculations and high-level thermochemical parametrizations. Broadband rotational spectroscopy offers quantitative and isomer-specific detection by which branching ratios of polar reaction products may be obtained. Using this technique, we observe and characterize products arising from H atom substitution reactions in the flash pyrolysis of acetone (CH3C(O)CH3) at a nominal temperature of 1800 K. The major product observed is ketene (CH2CO). Minor products identified include acetaldehyde (CH3CHO), propyne (CH3CCH), propene (CH2CHCH3), and water (HDO). Literature mechanisms for the pyrolysis of acetone do not adequately describe the minor products. The inclusion of a variety of substitution reactions, with rate constants and thermochemistry obtained from automated ab initio kinetics predictions and Active Thermochemical Tables analyses, demonstrates an important role for such processes. The pathway to acetaldehyde is shown to be a direct result of substitution of acetone's methyl group by a free H atom, while propene formation arises from OH substitution in the enol form of acetone by a free H atom.
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Affiliation(s)
- Daniel P Zaleski
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Chemistry, Colgate University, Hamilton, New York 13346, United States
| | - Raghu Sivaramakrishnan
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Hailey R Weller
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States.,Department of Chemical and Biomolecular Engineering, Vanderbilt University, Nashville, Tennessee 37235, United States
| | - Nathan A Seifert
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - David H Bross
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Branko Ruscic
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Kevin B Moore
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Sarah N Elliott
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Andreas V Copan
- Emmanuel College, Natural Sciences Department, Franklin Springs, Georgia 30639, United States
| | - Lawrence B Harding
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Stephen J Klippenstein
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Robert W Field
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Kirill Prozument
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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Mertens LA, Manion JA. Kinetics of isopropanol decomposition and reaction with H atoms from shock tube experiments and rate constant optimization using the method of uncertainty minimization using polynomial chaos expansions (MUM‐PCE). INT J CHEM KINET 2020. [DOI: 10.1002/kin.21428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Laura A. Mertens
- Chemical Sciences Division National Institute of Standards and Technology Gaithersburg Maryland
| | - Jeffrey A. Manion
- Chemical Sciences Division National Institute of Standards and Technology Gaithersburg Maryland
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Grajales-González E, Monge-Palacios M, Sarathy SM. Collision Efficiency Parameter Influence on Pressure-Dependent Rate Constant Calculations Using the SS-QRRK Theory. J Phys Chem A 2020; 124:6277-6286. [PMID: 32663402 PMCID: PMC7458424 DOI: 10.1021/acs.jpca.0c02943] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The system-specific quantum Rice-Ramsperger-Kassel (SS-QRRK) theory (J. Am. Chem. Soc. 2016, 138, 2690) is suitable to determine rate constants below the high-pressure limit. Its current implementation allows incorporating variational effects, multidimensional tunneling, and multistructural torsional anharmonicity in rate constant calculations. Master equation solvers offer a more rigorous approach to compute pressure-dependent rate constants, but several implementations available in the literature do not incorporate the aforementioned effects. However, the SS-QRRK theory coupled with a formulation of the modified strong collision model underestimates the value of unimolecular pressure-dependent rate constants in the high-temperature regime for reactions involving large molecules. This underestimation is a consequence of the definition for collision efficiency, which is part of the energy transfer model. Selection of the energy transfer model and its parameters constitutes a common issue in pressure-dependent calculations. To overcome this underestimation problem, we evaluated and implemented in a bespoke Python code two alternative definitions for the collision efficiency using the SS-QRRK theory and tested their performance by comparing the pressure-dependent rate constants with the Rice-Ramsperger-Kassel-Marcus/Master Equation (RRKM/ME) results. The modeled systems were the tautomerization of propen-2-ol and the decomposition of 1-propyl, 1-butyl, and 1-pentyl radicals. One of the tested definitions, which Dean et al. explicitly derived (Z. Phys. Chem. 2000, 214, 1533), corrected the underestimation of the pressure-dependent rate constants and, in addition, qualitatively reproduced the trend of RRKM/ME data. Therefore, the used SS-QRRK theory with accurate definitions for the collision efficiency can yield results that are in agreement with those from more sophisticated methodologies such as RRKM/ME.
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Affiliation(s)
- E Grajales-González
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
| | - M Monge-Palacios
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
| | - S Mani Sarathy
- Physical Sciences and Engineering Division, Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal, Jeddah 23955-6900, Saudi Arabia
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11
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Guo H, Yang X, Zwier T. Virtual Issue on Combustion Chemistry. J Phys Chem A 2020; 124:5995-5996. [PMID: 32698590 DOI: 10.1021/acs.jpca.0c05674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Monge-Palacios M, Grajales-González E, Sarathy SM. Ab Initio, Transition State Theory, and Kinetic Modeling Study of the HO 2-Assisted Keto-Enol Tautomerism Propen-2-ol + HO 2 ⇔ Acetone + HO 2 under Combustion, Atmospheric, and Interstellar Conditions. J Phys Chem A 2018; 122:9792-9805. [PMID: 30500199 DOI: 10.1021/acs.jpca.8b10369] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Keto-enol tautomerisms are important reactions in gaseous and liquid systems with implications in different chemical environments, but their kinetics have not been widely investigated. These reactions can proceed via a unimolecular process or may be catalyzed by another molecule. This work presents a theoretical study of the HO2-catalyzed tautomerism that converts propen-2-ol into acetone at conditions relevant to combustion, atmospheric and interstellar chemistry. We performed CCSD(T)/aug-cc-pVTZ//M06-2X/cc-pVTZ ab initio and multistructural torsional variational transition state theory calculations to compute the forward and reverse rate constants. These rate constants have not been investigated previously, and modelers approximate the kinetics by comparison to analogue reactions. Two features of the potential energy surface of the studied tautomerism are highlighted. First, the HO2 radical exhibits a pronounced catalytic effect by inducing a double hydrogen atom transfer reaction with a much lower barrier than that of the unimolecular process. Second, a prereactive complex is formed with a strong OH···π hydrogen bond. The role of the studied reaction under combustion conditions has been assessed via chemical kinetic modeling of 2-butanol (a potential alternative fuel) oxidation. The HO2-assisted process was found to not be competitive with the unimolecular and HCOOH-assisted tautomerisms. The rate constants for the formation of the prereactive complex were calculated with the variable reaction coordinate transition state theory, and pressure effects were estimated with the system-specific quantum Rice-Ramsperger-Kassel theory; this allowed us to investigate the role of the complex by using the canonical unified statistical model. The formation and equilibration of the prereactive complex, which is also important at low pressures, enhances the reactivity by inducing a large tunneling effect that leads to a significant increase of the rate constants at cold and ultracold temperatures. These findings may help to understand and model the fate of complex organic molecules in the interstellar medium, and suggest an alternative route for the high energy barrier keto-enol tautomerism which otherwise is not kinetically favored at low temperatures.
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Affiliation(s)
- M Monge-Palacios
- Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE) , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - E Grajales-González
- Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE) , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
| | - S Mani Sarathy
- Clean Combustion Research Center (CCRC), Physical Science and Engineering (PSE) , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia
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Lei X, Chen D, Wang W, Liu F, Wang W. Quantum chemical studies of the OH-initiated oxidation reactions of propenols in the presence of O2. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1537527] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Xiaoyang Lei
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Dongping Chen
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Weina Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Fengyi Liu
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
| | - Wenliang Wang
- Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi’an, People’s Republic of China
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