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Pereira RW, Ramabhadran RO. Accurate Computation of Aqueous p Kas of Biologically Relevant Organic Acids: Overcoming the Challenges Posed by Multiple Conformers, Tautomeric Equilibria, and Disparate Functional Groups with the Fully Black-Box p K-Yay Method. J Phys Chem A 2023; 127:9121-9138. [PMID: 37862610 DOI: 10.1021/acs.jpca.3c02977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
The use of static electronic structure calculations to compute solution-phase pKas offers a great advantage in that a macroscopic bulk property could be computed via microscopic computations involving very few molecules. There are various sources of errors in the quantum chemical calculations though. Overcoming these errors to accurately compute pKas of a plethora of acids is an active area of research in physical chemistry pursued by both computational as well as experimental chemists. We recently developed the pK-Yay method in our attempt to accurately compute aqueous pKas of strong and weak acids. The method is fully black-box, computationally inexpensive, and is very easy for even a nonexpert to use. However, the method was thus far tested on very few molecules (only 16 in all). Herein, in order to assess the future applicability of pK-Yay, we study the effect of multiple conformers, the presence of tautomers under equilibrium, and the impact of a wide variety of functional groups (derivatives of acetic acid with substituents at various positions, dicarboxylic acids, aromatic carboxylic acids, amines and amides, phenols and thiols, and fluorine bearing organic acids). Starting with more than 1000 conformers and tautomers, this study establishes that overall errors of ∼ 1.0 pKa units are routinely obtained for a majority of the molecules. Larger errors are noted in cases where multiple charges, intramolecular hydrogen bonding, and several ionizable functional groups are simultaneously present. An important conclusion to emerge from this work is that, the computed pKas are insensitive (difference <0.5) to whether we consider multiple conformers/tautomers or only choose the most stable conformer/tautomer. Further, pK-Yay captures the stereoelectronic effects arising due to differing axial vs equatorial pattern, and is useful to predict the dominant acid-base equilibrium in a system featuring several equilibria. Overall, pK-Yay may be employed in several chemical applications featuring organic molecules and biomonomers.
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Affiliation(s)
- Roshni W Pereira
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Andhra Pradesh 517507, India
- Centre for Atomic Molecular Optical Sciences and Technology (CAMOST), Tirupati, Andhra Pradesh 517507, India
| | - Raghunath O Ramabhadran
- Department of Chemistry, Indian Institute of Science Education and Research (IISER) Tirupati, Andhra Pradesh 517507, India
- Centre for Atomic Molecular Optical Sciences and Technology (CAMOST), Tirupati, Andhra Pradesh 517507, India
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2
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Lahm ME, Bartlett MA, Liang T, Pu L, Allen WD, Schaefer HF. The multichannel i-propyl + O2 reaction system: A model of secondary alkyl radical oxidation. J Chem Phys 2023; 159:024305. [PMID: 37428067 DOI: 10.1063/5.0156705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 06/19/2023] [Indexed: 07/11/2023] Open
Abstract
The i-propyl + O2 reaction mechanism has been investigated by definitive quantum chemical methods to establish this system as a benchmark for the combustion of secondary alkyl radicals. Focal point analyses extrapolating to the ab initio limit were performed based on explicit computations with electron correlation treatments through coupled cluster single, double, triple, and quadruple excitations and basis sets up to cc-pV5Z. The rigorous coupled cluster single, double, and triple excitations/cc-pVTZ level of theory was used to fully optimize all reaction species and transition states, thus, removing some substantial flaws in reference geometries existing in the literature. The vital i-propylperoxy radical (MIN1) and its concerted elimination transition state (TS1) were found 34.8 and 4.4 kcal mol-1 below the reactants, respectively. Two β-hydrogen transfer transition states (TS2, TS2') lie above the reactants by (1.4, 2.5) kcal mol-1 and display large Born-Oppenheimer diagonal corrections indicative of nearby surface crossings. An α-hydrogen transfer transition state (TS5) is discovered 5.7 kcal mol-1 above the reactants that bifurcates into equivalent α-peroxy radical hanging wells (MIN3) prior to a highly exothermic dissociation into acetone + OH. The reverse TS5 → MIN1 intrinsic reaction path also displays fascinating features, including another bifurcation and a conical intersection of potential energy surfaces. An exhaustive conformational search of two hydroperoxypropyl (QOOH) intermediates (MIN2 and MIN3) of the i-propyl + O2 system located nine rotamers within 0.9 kcal mol-1 of the corresponding lowest-energy minima.
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Affiliation(s)
- Mitchell E Lahm
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Marcus A Bartlett
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Tao Liang
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Liang Pu
- College of Chemistry and Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People's Republic of China
| | - Wesley D Allen
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
- Allen Heritage Foundation, Dickson, Tennessee 37055, USA
| | - Henry F Schaefer
- Center for Computational Quantum Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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3
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Nacsa AB, Kígyósi M, Czakó G. Protonation of serine: conformers, proton affinities and gas-phase basicities at the "gold standard" and beyond. Phys Chem Chem Phys 2023; 25:8891-8902. [PMID: 36916632 DOI: 10.1039/d3cp00612c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
The potential energy surfaces (PESs) of serine and its protonated counterparts are investigated to determine the structures of the minima. A total of 95 neutral serine, 15 N-(amino-) and 46 O-(carbonyl-)protonated serine conformers are found. Their relative energies, geometries and harmonic vibrational frequencies are determined at the MP2/aug-cc-pVDZ level of theory. To obtain highly accurate thermodynamic values, further computations are performed: the ten conformers with the lowest relative energies from each molecule type (neutral, N- and O-protonated) are further optimized using the explicitly correlated CCSD(T)-F12a/cc-pVDZ-F12 method (for neutral serine, harmonic vibrational frequencies were also computed). In addition, auxiliary corrections were determined: basis-set effects up to CCSD(T)-F12b/cc-pVQZ-F12, electron correlation effects up to CCSDT(Q), core correlation and second-order Douglas-Kroll relativistic effects along with zero-point energy contributions. Two important thermodynamic parameters (at 298.15 K), proton affinity (PA)/gas-phase basicity (GB) are calculated considering the two different protonation sites: 218.05 ± 0.2/209.86 ± 0.6 kcal mol-1 and 205.87 ± 0.2/196.36 ± 0.3 kcal mol-1 for the amino and carbonyl sites, respectively. The uncertainty of the determined values was approximated based on various sources including auxiliary corrections, basis-set effects, harmonic vibrational frequencies.
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Affiliation(s)
- András B Nacsa
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary.
| | - Máté Kígyósi
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary.
| | - Gábor Czakó
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Rerrich Béla tér 1, Szeged H-6720, Hungary.
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4
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Barone V, Fusè M, Lazzari F, Mancini G. Benchmark Structures and Conformational Landscapes of Amino Acids in the Gas Phase: A Joint Venture of Machine Learning, Quantum Chemistry, and Rotational Spectroscopy. J Chem Theory Comput 2023; 19:1243-1260. [PMID: 36731119 PMCID: PMC9979611 DOI: 10.1021/acs.jctc.2c01143] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The accurate characterization of prototypical bricks of life can strongly benefit from the integration of high resolution spectroscopy and quantum mechanical computations. We have selected a number of representative amino acids (glycine, alanine, serine, cysteine, threonine, aspartic acid and asparagine) to validate a new computational setup rooted in quantum-chemical computations of increasing accuracy guided by machine learning tools. Together with low-lying energy minima, the barriers ruling their interconversion are evaluated in order to unravel possible fast relaxation paths. Vibrational and thermal effects are also included in order to estimate relative free energies at the temperature of interest in the experiment. The spectroscopic parameters of all the most stable conformers predicted by this computational strategy, which do not have low-energy relaxation paths available, closely match those of the species detected in microwave experiments. Together with their intrinsic interest, these accurate results represent ideal benchmarks for more approximate methods.
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Affiliation(s)
- Vincenzo Barone
- Scuola
Normale Superiore di Pisa, piazza dei Cavalieri 7, 56126 Pisa, Italy,
| | - Marco Fusè
- DMMT-sede
Europa, Universitá di Brescia, viale Europa 11, 25121 Brescia, Italy
| | - Federico Lazzari
- Scuola
Normale Superiore di Pisa, piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - Giordano Mancini
- Scuola
Normale Superiore di Pisa, piazza dei Cavalieri 7, 56126 Pisa, Italy
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Wang Z, Dan G, Zhang R, Ma L, Lin K. Coupling and decoupling CH stretching vibration of methylene and methine in serine conformers. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 285:121829. [PMID: 36116413 DOI: 10.1016/j.saa.2022.121829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 08/29/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
In the molecules of the early Earth, as a building block of proteins, serine has enormous chemical and biological significance. The vibrational spectroscopy of CH bonds plays an important role in probing biomolecules. Whether the CH stretching vibration bands can be accurately assigned will affect the accuracy of the detection results. In this study, we employed the MP2/cc-pVTZ method to calculate the Raman spectra of 85 serine conformers and the corresponding species with deuterium in the CH stretching region from 2800 cm-1 to 3050 cm-1 and then recorded the movement of each atom and the dihedral angles, CH bond lengths, and Raman shifts before and after deuterium for each conformer. We directly observed that the stretching vibration of two CH bonds in the methylene group decoupled to vibrate independently in some conformers, and the stretching vibrations of methylene and methine could be strongly coupled in some conformers. Those results are inconsistent with the traditional understanding, which is generally believed that the CH stretching vibrations are mutually coupled in a single methyl or methylene group to generate symmetric and antisymmetric stretching vibrations, while for different methyl, methylene or methine groups, the CH stretching vibrations cannot be mutually coupled. Through the statistical analysis between several factors, we found that the level of local coupling in serine methylene was correlated with the bond length difference between two CH bonds. Our work provides a new understanding of the vibrational modes of hydrocarbon bonds and the coupling between different hydrocarbon groups.
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Affiliation(s)
- Zhiqiang Wang
- School of Physics, Xidian University, Xi'an 710071, PR China
| | - Guangyu Dan
- School of Physics, Xidian University, Xi'an 710071, PR China
| | - Ruiting Zhang
- School of Physics, Xidian University, Xi'an 710071, PR China
| | - Lin Ma
- School of Physics, Xidian University, Xi'an 710071, PR China
| | - Ke Lin
- School of Physics, Xidian University, Xi'an 710071, PR China; Interdisciplinary Research Center of Smart Sensor, Xidian University, Xi'an 710071, PR China.
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6
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Dékány AÁ, Czakó G. Benchmark ab initio proton affinity and gas-phase basicity of α-alanine based on coupled-cluster theory and statistical mechanics. J Comput Chem 2022; 43:19-28. [PMID: 34676890 DOI: 10.1002/jcc.26767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 09/16/2021] [Accepted: 09/27/2021] [Indexed: 11/06/2022]
Abstract
We determine the proton affinity (PA) and gas-phase basicity (GB) of amino acid α-alanine at a chemically accurate level by performing explicitly-correlated CCSD(T)-F12b/aug-cc-pVDZ geometry optimizations and normal mode vibrational frequency calculations as well as CCSD(T)-F12b/aug-cc-pVTZ energy computations at the possible neutral and protonated geometries. Temperature effects at 298.15 K considering translational, rotational, and vibrational enthalpy and entropy corrections are obtained via standard statistical mechanics utilizing the molecular geometries and the harmonic vibrational energy levels. Both the amino nitrogen (N) and the carbonyl oxygen (O) atoms are proven to be potential protonation sites and a systematic conformational search reveals 3 N- and 9 O-protonated conformers in the 0.00-7.88 and 25.43-30.43 kcal/mol energy ranges at 0 K, respectively. The final computed PA and GB values at (0)298.15 K in case of N-protonation are (214.47)216.80 and 207.07 kcal/mol, respectively, whereas the corresponding values for O-protonation are (189.04)190.63 and 182.31 kcal/mol. The results of the benchmark high-level coupled-cluster computations are utilized to assess the accuracy of several lower-level cost-effective methods such as MP2 and density functional theory with various functionals (SOGGA11-X, M06-2X, PBE0, B3LYP, M06, TPSS).
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Affiliation(s)
- Attila Á Dékány
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Szeged, Hungary
| | - Gábor Czakó
- MTA-SZTE Lendület Computational Reaction Dynamics Research Group, Interdisciplinary Excellence Centre and Department of Physical Chemistry and Materials Science, Institute of Chemistry, University of Szeged, Szeged, Hungary
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7
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Sheng M, Silvestrini F, Biczysko M, Puzzarini C. Structural and Vibrational Properties of Amino Acids from Composite Schemes and Double-Hybrid DFT: Hydrogen Bonding in Serine as a Test Case. J Phys Chem A 2021; 125:9099-9114. [PMID: 34623165 DOI: 10.1021/acs.jpca.1c06993] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The structures, relative stabilities, and vibrational wavenumbers of the two most stable conformers of serine, stabilized by the O-H···N, O-H···O═C and N-H···O-H intramolecular hydrogen bonds, have been evaluated by means of state-of-the-art composite schemes based on coupled-cluster (CC) theory. The so-called "cheap" composite approach (CCSD(T)/(CBS+CV)MP2) allowed determination of accurate equilibrium structures and harmonic vibrational wavenumbers, also pointing out significant corrections beyond the CCSD(T)/cc-pVTZ level. These accurate results stand as a reference for benchmarking selected hybrid and double-hybrid, dispersion-corrected DFT functionals. B2PLYP-D3 and DSDPBEP86 in conjunction with a triple-ζ basis set have been confirmed as effective methodologies for structural and spectroscopic studies of medium-sized flexible biomolecules, also showing intramolecular hydrogen bonding. These best performing double-hybrid functionals have been employed to simulate IR spectra by means of vibrational perturbation theory, also considering hybrid CC/DFT schemes. The best overall agreement with experiment, with mean absolute error of 8 cm-1, has been obtained by combining CCSD(T)/(CBS+CV)MP2 harmonic wavenumbers with B2PLYP-D3/maug-cc-pVTZ anharmonic corrections. Finally, a composite scheme entirely based on CCSD(T) calculations (CCSD(T)/CBS+CV) has been employed for energetics, further confirming that serine II is the most stable conformer, also when zero-point vibrational energy corrections are included.
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Affiliation(s)
- Mingzhu Sheng
- International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Filippo Silvestrini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
| | - Malgorzata Biczysko
- International Centre for Quantum and Molecular Structures, Physics Department, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Cristina Puzzarini
- Department of Chemistry "Giacomo Ciamician", University of Bologna, Via F. Selmi 2, 40126 Bologna, Italy
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8
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Ball BT, Vanovac S, Odbadrakh TT, Shields GC. Monomers of Glycine and Serine Have a Limited Ability to Hydrate in the Atmosphere. J Phys Chem A 2021; 125:8454-8467. [PMID: 34529444 DOI: 10.1021/acs.jpca.1c05466] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The role of atmospheric aerosols on climate change is one of the biggest uncertainties in most global climate models. Organic aerosols have been identified as potential cloud condensation nuclei (CCN), and amino acids are organic molecules that could serve as CCN. Amino acids make up a significant portion of the total organic material in the atmosphere, and herein we present a systematic study of hydration for two of the most common atmospheric amino acids, glycine and serine. We compute DLPNO/CCSD(T)//M08-HX/MG3S thermodynamic properties and atmospheric concentrations of Gly(H2O)n and Ser(H2O)n, where n = 1-5. We predict that serine-water clusters have higher concentrations at n = 1 and 5, while glycine-water clusters have higher concentrations at n = 2-4. However, both glycine and serine are inferred to exist primarily in their nonhydrated monomer forms in the absence of other species such as sulfuric acid.
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Affiliation(s)
- Benjamin T Ball
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
| | - Sara Vanovac
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
| | - Tuguldur T Odbadrakh
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
| | - George C Shields
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, United States
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9
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Hartweg S, Garcia GA, Božanić DK, Nahon L. Condensation Effects on Electron Chiral Asymmetries in the Photoionization of Serine: From Free Molecules to Nanoparticles. J Phys Chem Lett 2021; 12:2385-2393. [PMID: 33660503 DOI: 10.1021/acs.jpclett.1c00258] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Structural changes at the molecular level, occurring at the onset of condensation, can be probed by angle-resolved valence photoelectron spectroscopy, which is inherently sensitive to the electronic structure. For larger condensed systems like aerosol particles, the observation of intrinsic angular anisotropies in photoemission (β parameters) is challenging due to the strong reduction of their magnitude by electron transport effects. Here, we use a less common, more sensitive observable in the form of the chiral asymmetry parameter to perform a comparative study of the VUV photoelectron spectroscopy and photoelectron circular dichroism (PECD) between pure gas phase enantiomers of the amino acid serine and their corresponding homochiral nanoparticles. We observe a relatively large (1%) and strongly kinetic energy-dependent asymmetry, discussed in terms of the emergence of local order and conformational changes potentially counterbalancing the loss of angular information due to electron transport scattering. This demonstrates the potential of PECD as a sensitive probe of the condensation effects from the gas phase to bulk-like chiral aerosol particles surpassing the potential of conventional photoemission observables such as β parameters.
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Affiliation(s)
- Sebastian Hartweg
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
| | - Gustavo A Garcia
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
| | - Dušan K Božanić
- Department of Radiation Chemistry and Physics, "VINČA" Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, 11001 Belgrade, Serbia
| | - Laurent Nahon
- Synchrotron SOLEIL, l'Orme des Merisiers, Saint Aubin BP 48, 91192 Cedex, Gif sur Yvette, France
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Mancini G, Fusè M, Lazzari F, Chandramouli B, Barone V. Unsupervised search of low-lying conformers with spectroscopic accuracy: A two-step algorithm rooted into the island model evolutionary algorithm. J Chem Phys 2020; 153:124110. [DOI: 10.1063/5.0018314] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Giordano Mancini
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Marco Fusè
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Federico Lazzari
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
| | | | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56125 Pisa, Italy
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Yanase S, Musashi M, Oi T. Nitrogen Isotopic Reduced Partition Function Ratios of Glycine and Serine in Water. J Phys Chem A 2020; 124:5212-5229. [PMID: 32460486 DOI: 10.1021/acs.jpca.0c04010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The nitrogen isotopic reduced partition function ratio (RPFR) of glycine (Gly) and serine (Ser) in water has been evaluated by a couple of methods. The experimental fact that those amino acids are present in the zwitterionic form in water has been best reproduced when trihydrated Gly and Ser molecules were treated by the discrete microsolvation method coupled with the self-consistent reaction field (SCRF) approach. The RPFR values of Gly and Ser in water at 25 °C are evaluated as 1.11152 and 1.11070, respectively, and the equilibrium constant of the nitrogen isotope exchange reaction between the two amino acids is calculated as 1.0007 ± 0.0008 at 25 °C. Equivalent results may be obtained by the SCRF method for non- and monohydrated molecules in the zwitterionic form.
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Affiliation(s)
- Satoshi Yanase
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan
| | - Masaaki Musashi
- Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, 1-1 minami-Osawa, Hachioji-shi, Tokyo 192-0397, Japan
| | - Takao Oi
- Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan
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12
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Fang B, Ning F, Hu S, Guo D, Ou W, Wang C, Wen J, Sun J, Liu Z, Koh CA. The effect of surfactants on hydrate particle agglomeration in liquid hydrocarbon continuous systems: a molecular dynamics simulation study. RSC Adv 2020; 10:31027-31038. [PMID: 35520650 PMCID: PMC9056346 DOI: 10.1039/d0ra04088f] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 07/14/2020] [Indexed: 12/02/2022] Open
Abstract
Anti-agglomerants (AAs), both natural and commercial, are currently being considered for gas hydrate risk management of petroleum pipelines in offshore operations. However, the molecular mechanisms of the interaction between the AAs and gas hydrate surfaces and the prevention of hydrate agglomeration remain critical and complex questions that need to be addressed to advance this technology. Here, we use molecular dynamics (MD) simulations to investigate the effect of model surfactant molecules (polynuclear aromatic carboxylic acids) on the agglomeration behaviour of gas hydrate particles and disruption of the capillary liquid bridge between hydrate particles. The results show that the anti-agglomeration pathway can be divided into two processes: the spontaneous adsorption effect of surfactant molecules onto the hydrate surface and the weakening effect of the intensity of the liquid bridge between attracted hydrate particles. The MD simulation results also indicate that the anti-agglomeration effectiveness of surfactants is determined by the intrinsic nature of their molecular functional groups. Additionally, we find that surfactant molecules can affect hydrate growth, which decreases hydrate particle size and correspondingly lower the risk of hydrate agglomeration. This study provides molecular-level insights into the anti-agglomeration mechanism of surfactant molecules, which can aid in the ultimate application of natural or commercial AAs with optimal anti-agglomeration properties. Schematic of anti-agglomeration effect of surfactants promoting gas hydrate particle dispersion.![]()
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13
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Fusè M, Mazzeo G, Longhi G, Abbate S, Masi M, Evidente A, Puzzarini C, Barone V. Unbiased Determination of Absolute Configurations by vis-à-vis Comparison of Experimental and Simulated Spectra: The Challenging Case of Diplopyrone. J Phys Chem B 2019; 123:9230-9237. [PMID: 31580674 DOI: 10.1021/acs.jpcb.9b08375] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A new experimental-computational strategy for the determination of the absolute configuration (AC) of complex chiral molecules is proposed by combining diverse experimental spectroscopies with quantum-mechanical simulations well beyond the current computational practice. Key features are the conformer search and relative stability evaluation performed by a new stochastic two-level tool followed by a vis-à-vis comparison of experimental and computed spectra without any ad hoc adjustment. The entire computational procedure is embedded in the user-friendly VMS software, and its reliability is granted by the inclusion of mechanic/electric/magnetic anharmonicity as well as ro-vibrational and vibronic couplings by means of generalized perturbation theory in conjunction with double-hybrid functionals combined with empirical dispersion contributions and suitable basis sets. To test and validate the new approach, the puzzling case of diplopyrone, a fungal phytotoxic metabolite, has been chosen: the close match between new experimental and simulated infrared absorption and vibrational circular dichroism spectra has led to the unbiased evaluation of its AC.
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Affiliation(s)
- Marco Fusè
- Scuola Normale Superiore , Piazza dei Cavalieri 7 , I-56126 Pisa , Italy
| | - Giuseppe Mazzeo
- Dipartimento di Medicina Molecolare e Traslazionale , Università di Brescia , Viale Europa 11 , 25123 Brescia , Italy
| | - Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale , Università di Brescia , Viale Europa 11 , 25123 Brescia , Italy.,Consiglio Nazionale delle Ricerche-I.N.O. c/o CSMT , via Branze, 45 - 25123 Brescia , Italy
| | - Sergio Abbate
- Dipartimento di Medicina Molecolare e Traslazionale , Università di Brescia , Viale Europa 11 , 25123 Brescia , Italy.,Consiglio Nazionale delle Ricerche-I.N.O. c/o CSMT , via Branze, 45 - 25123 Brescia , Italy
| | - Marco Masi
- Dipartimento di Scienze Chimiche , Università di Napoli Federico II , Complesso Universitario Monte S. Angelo, Via Cintia 4 , 80126 Napoli , Italy
| | - Antonio Evidente
- Dipartimento di Scienze Chimiche , Università di Napoli Federico II , Complesso Universitario Monte S. Angelo, Via Cintia 4 , 80126 Napoli , Italy
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician" , Università di Bologna , Via Selmi 2 , I-40126 Bologna , Italy
| | - Vincenzo Barone
- Scuola Normale Superiore , Piazza dei Cavalieri 7 , I-56126 Pisa , Italy
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14
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Feller D, Bross DH, Ruscic B. Enthalpy of Formation of C2H2O4 (Oxalic Acid) from High-Level Calculations and the Active Thermochemical Tables Approach. J Phys Chem A 2019; 123:3481-3496. [DOI: 10.1021/acs.jpca.8b12329] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- David Feller
- Department of Chemistry, Washington State University, Pullman, Washington 99164-4630, United States
| | - David H. Bross
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Branko Ruscic
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
- Consortium for Advanced Science and Engineering, The University of Chicago, Chicago, Illinois 60637, United States
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15
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Tong H, Liu YF, Yan H, Jiang C, Gao F, Mei Z, Hong K, Yang X, Wang Z. Theoretical investigation of the chiral transition of serine and the roles of water, hydroxyl radical and hydroxide ion. NEW J CHEM 2019. [DOI: 10.1039/c9nj01796h] [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
The serine chiral transition and the roles of water, hydroxyl radical and hydroxide ion as catalysts were theoretically investigated.
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Affiliation(s)
- Hua Tong
- The Department of Physics
- The Institute of Theoretical and Computational Research
- Baicheng Normal University
- Baicheng 137000
- China
| | - Yan Fang Liu
- National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization
- Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province
- Huaiyin Institute of Technology
- Huaian 223003
- China
| | - Hongyan Yan
- Department of Computer Science
- Baicheng Normal University
- Baicheng 137000
- China
| | - Chunxu Jiang
- The Department of Physics
- The Institute of Theoretical and Computational Research
- Baicheng Normal University
- Baicheng 137000
- China
| | - Feng Gao
- The Department of Physics
- The Institute of Theoretical and Computational Research
- Baicheng Normal University
- Baicheng 137000
- China
| | - Zemin Mei
- Department of Chemistry
- Baicheng Normal University
- Baicheng 137000
- China
| | - Kun Hong
- National & Local Joint Engineering Research Center for Mineral Salt Deep Utilization
- Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province
- Huaiyin Institute of Technology
- Huaian 223003
- China
| | - Xiaocui Yang
- The Department of Physics
- The Institute of Theoretical and Computational Research
- Baicheng Normal University
- Baicheng 137000
- China
| | - Zuocheng Wang
- The Department of Physics
- The Institute of Theoretical and Computational Research
- Baicheng Normal University
- Baicheng 137000
- China
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16
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Chopra G, Chopra N, Kaur D. Quantum chemical study of hydrogen-bonded complexes of serine with water and $$\hbox {H}_{2}\hbox {O}_{2}$$ H 2 O 2. J CHEM SCI 2018. [DOI: 10.1007/s12039-018-1506-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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17
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Bartlett MA, Liang T, Pu L, Schaefer HF, Allen WD. The multichannel n-propyl + O2 reaction surface: Definitive theory on a model hydrocarbon oxidation mechanism. J Chem Phys 2018. [DOI: 10.1063/1.5017305] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Marcus A. Bartlett
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Tao Liang
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Liang Pu
- College of Chemistry & Pharmacy, Northwest A&F University, Yangling, Shaanxi 712100, People’s Republic of China
| | - Henry F. Schaefer
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
| | - Wesley D. Allen
- Center for Computational Chemistry and Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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18
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Feller D, Bross DH, Ruscic B. Enthalpy of Formation of N2H4 (Hydrazine) Revisited. J Phys Chem A 2017; 121:6187-6198. [DOI: 10.1021/acs.jpca.7b06017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Feller
- Department
of Chemistry Washington State University, Pullman, Washington 99164-4630, United States
| | - David H. Bross
- Chemical
Sciences and Engineering Division Argonne National Laboratory Argonne, Illinois 60439, United States
| | - Branko Ruscic
- Chemical
Sciences and Engineering Division Argonne National Laboratory Argonne, Illinois 60439, United States
- Computation
Institute, The University of Chicago, Chicago, Illinois 60637, United States
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19
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Feller D. Estimating the intrinsic limit of the Feller-Peterson-Dixon composite approach when applied to adiabatic ionization potentials in atoms and small molecules. J Chem Phys 2017; 147:034103. [DOI: 10.1063/1.4993625] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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20
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Braga CB, Rittner R. Combined Utilization of 1H NMR, IR, and Theoretical Calculations To Elucidate the Conformational Preferences of Some l-Histidine Derivatives. J Phys Chem A 2017; 121:729-740. [DOI: 10.1021/acs.jpca.6b12515] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Carolyne B. Braga
- Chemistry Institute, University of Campinas, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
| | - Roberto Rittner
- Chemistry Institute, University of Campinas, P.O. Box 6154, 13083-970 Campinas, SP, Brazil
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