1
|
Mackie CJ, Candian A, Lee TJ, Tielens AGGM. Modeling the infrared cascade spectra of small PAHs: the 11.2 μm band. Theor Chem Acc 2021; 140:124. [PMID: 34720707 PMCID: PMC8549957 DOI: 10.1007/s00214-021-02807-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 07/02/2021] [Indexed: 11/18/2022]
Abstract
The profile of the 11.2 μm feature of the infrared (IR) cascade emission spectra of polycyclic aromatic hydrocarbon (PAH) molecules is investigated using a vibrational anharmonic method. Several factors are found to affect the profile including: the energy of the initially absorbed ultraviolet (UV) photon, the density of vibrational states, the anharmonic nature of the vibrational modes, the relative intensities of the vibrational modes, the rotational temperature of the molecule, and blending with nearby features. Each of these factors is explored independently and influence either the red or blue wing of the 11.2 μm feature. The majority impact solely the red wing, with the only factor altering the blue wing being the rotational temperature.
Collapse
Affiliation(s)
- Cameron J Mackie
- Kenneth S. Pitzer Center for Theoretical Chemistry Department of Chemistry, University of California, Berkeley, CA 94720 USA.,Lawrence Berkeley National Laboratory, Chemical Sciences Division, Berkeley, CA 94720 USA
| | - Alessandra Candian
- van 't Hoff Institute for Molecular Science, University of Amsterdam, P.O. Box 94157, 1090 GD Amsterdam, The Netherlands
| | - Timothy J Lee
- NASA Ames Research Center, Moffett Field, CA 94035-1000 USA
| | - Alexander G G M Tielens
- Leiden Observatory, Leiden University, P.O. Box 9513, 2300 RA Leiden, The Netherlands.,Astronomy Department, University of Maryland, College Park, MD 20742 USA
| |
Collapse
|
2
|
Chakraborty S, Mulas G, Rapacioli M, Joblin C. Anharmonic Infrared Spectra of Thermally Excited Pyrene (C 16H 10): A Combined View of DFT-Based GVPT2 with AnharmonicCaOs, and Approximate DFT Molecular dynamics with DemonNano. JOURNAL OF MOLECULAR SPECTROSCOPY 2021; 378:111466. [PMID: 34257467 PMCID: PMC7611198 DOI: 10.1016/j.jms.2021.111466] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The study of the Aromatic Infrared Bands (AIBs) in astronomical environments has opened interesting spectroscopic questions on the effect of anharmonicity on the infrared (IR) spectrum of hot polycyclic aromatic hydrocarbons (PAHs) and related species in isolated conditions. The forthcoming James Webb Space Telescope will unveil unprecedented spatial and spectral details in the AIB spectrum; significant advancement is thus necessary now to model the infrared emission of PAHs, their presumed carriers, with enough detail to exploit the information content of the AIBs. This requires including anharmonicity in such models, and to do so systematically for all species included, requiring a difficult compromise between accuracy and efficiency. We performed a benchmark study to compare the performances of two methods in calculating anharmonic spectra, comparing them to available experimental data. One is a full quantum method, AnharmoniCaOs, relying on an ab initio potential, and the other relies on Molecular Dynamics simulations using a Density Functional based Tight Binding potential. The first one is found to be very accurate and detailed, but it becomes computationally very expensive for increasing temperature; the second is faster and can be used for arbitrarily high temperatures, but is less accurate. Still, its results can be used to model the evolution with temperature of isolated bands. We propose a new recipe to model anharmonic AIB emission using minimal assumptions on the general behaviour of band positions and widths with temperature, which can be defined by a small number of empirical parameters. Modelling accuracy will depend critically on these empirical parameters, allowing for an incremental improvement in model results, as better estimates become gradually available.
Collapse
Affiliation(s)
- Shubhadip Chakraborty
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse (UPS), CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| | - Giacomo Mulas
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse (UPS), CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
- Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Cagliari, 09047 Selargius (CA), Italy
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques (LCPQ/IRSAMC), Université de Toulouse (UPS),CNRS, 118 Route de Narbonne, 31062 Toulouse, France
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse (UPS), CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| |
Collapse
|
3
|
Abstract
Recently, AIMD (ab initio molecular dynamics) has been extensively employed to explore the dynamical information of electronic systems. However, it remains extremely challenging to reliably predict the properties of nanosystems with a radical nature using conventional electronic structure methods (e.g., Kohn-Sham density functional theory) due to the presence of static correlation. To address this challenge, we combine the recently formulated TAO-DFT (thermally-assisted-occupation density functional theory) with AIMD. The resulting TAO-AIMD method is employed to investigate the instantaneous/average radical nature and infrared spectra of n-acenes containing n linearly fused benzene rings (n = 2-8) at 300 K. According to the TAO-AIMD simulations, on average, the smaller n-acenes (up to n = 5) possess a nonradical nature, and the larger n-acenes (n = 6-8) possess an increasing radical nature, showing remarkable similarities to the ground-state counterparts at 0 K. Besides, the infrared spectra of n-acenes obtained with the TAO-AIMD simulations are in qualitative agreement with the existing experimental data.
Collapse
Affiliation(s)
- Shaozhi Li
- Department of Physics, National Taiwan University, Taipei, Taiwan
| | - Jeng-Da Chai
- Department of Physics, National Taiwan University, Taipei, Taiwan
- Center for Theoretical Physics and Center for Quantum Science and Engineering, National Taiwan University, Taipei, Taiwan
| |
Collapse
|
4
|
Dontot L, Spiegelman F, Zamith S, Rapacioli M. Dependence upon charge of the vibrational spectra of small Polycyclic Aromatic Hydrocarbon clusters: the example of pyrene. THE EUROPEAN PHYSICAL JOURNAL. D, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 2020; 74:216. [PMID: 33597829 PMCID: PMC7116754 DOI: 10.1140/epjd/e2020-10081-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 07/18/2020] [Accepted: 09/01/2020] [Indexed: 06/12/2023]
Abstract
Infrared spectra are computed for neutral and cationic clusters of Polycyclic Aromatic Hydrocarbon clusters, namely( C 16 H 10 ) n = 1 , 4 ( 0 / + ) , using the Density Functional based Tight Binding scheme combined with a Configuration Interaction scheme (DFTB-CI) in the double harmonic approximation. Cross-comparison is carried out with DFT and simple DFTB. Similarly to the monomer cation, the IR spectra of cluster cations are characterized by a depletion of the intensity of the CH stretch modes around 3000 cm-1, with a weak revival for n = 3 and 4. The in-plane CCC modes in the region 1400-2000 cm-1 are enhanced while the CH bending modes in the range 700-1000 cm-1 are significantly weakened with respect to the monomer cation, in particular for n = 2. Finally, soft modes corresponding to diedral fluctuations of the monomers within the central stack of the ion structure, possibly mixed with monomer folding, are also observed in the region 70-120 cm-1.
Collapse
Affiliation(s)
- Léo Dontot
- Laboratoire de Chimie et Physique Quantique (LCPQ/IRSAMC), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantique (LCPQ/IRSAMC), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Sébastien Zamith
- Laboratoire Collisions Agrégats Réactivité (LCAR/IRSAMC), UMR5589, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantique (LCPQ/IRSAMC), UMR5626, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| |
Collapse
|
5
|
Spiegelman F, Tarrat N, Cuny J, Dontot L, Posenitskiy E, Martí C, Simon A, Rapacioli M. Density-functional tight-binding: basic concepts and applications to molecules and clusters. ADVANCES IN PHYSICS: X 2020; 5:1710252. [PMID: 33154977 PMCID: PMC7116320 DOI: 10.1080/23746149.2019.1710252] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 12/19/2019] [Indexed: 06/10/2023] Open
Abstract
The scope of this article is to present an overview of the Density Functional based Tight Binding (DFTB) method and its applications. The paper introduces the basics of DFTB and its standard formulation up to second order. It also addresses methodological developments such as third order expansion, inclusion of non-covalent interactions, schemes to solve the self-interaction error, implementation of long-range short-range separation, treatment of excited states via the time-dependent DFTB scheme, inclusion of DFTB in hybrid high-level/low level schemes (DFT/DFTB or DFTB/MM), fragment decomposition of large systems, large scale potential energy landscape exploration with molecular dynamics in ground or excited states, non-adiabatic dynamics. A number of applications are reviewed, focusing on -(i)- the variety of systems that have been studied such as small molecules, large molecules and biomolecules, bare orfunctionalized clusters, supported or embedded systems, and -(ii)- properties and processes, such as vibrational spectroscopy, collisions, fragmentation, thermodynamics or non-adiabatic dynamics. Finally outlines and perspectives are given.
Collapse
Affiliation(s)
- Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
| | - Nathalie Tarrat
- CEMES, Université de Toulouse (UPS), CNRS, UPR8011, Toulouse, Toulouse, France
| | - Jérôme Cuny
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
| | - Leo Dontot
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
| | - Evgeny Posenitskiy
- Laboratoire Collisions Agrégats et Réactivité LCAR/IRSAMC, UMR5589, Université de Toulouse (UPS) and CNRS, Toulouse, France
| | - Carles Martí
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
- Laboratoire de Chimie, UMR5182, Ecole Normale Supérieure de Lyon, Université de Lyon and CNRS, Lyon, France
| | - Aude Simon
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, UMR5626, Université de Toulouse (UPS)and CNRS, Toulouse, France
| |
Collapse
|
6
|
Zamitha S, Ji MC, L’Hermite JM, Joblin C, Dontot L, Rapacioli M, Spiegelman F. Thermal evaporation of pyrene clusters. J Chem Phys 2019; 151:194303. [PMID: 31757155 PMCID: PMC6908449 DOI: 10.1063/1.5100264] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
This work presents a study of the thermal evaporation and stability of pyrene (C16H10)n clusters. Thermal evaporation rates of positively charged mass-selected clusters are measured for sizes in the range n = 3-40 pyrene units. The experimental setup consists of a gas aggregation source, a thermalization chamber, and a time of flight mass spectrometer. A microcanonical Phase Space Theory (PST) simulation is used to determine the dissociation energies of pyrene clusters by fitting the experimental breakdown curves. Calculations using the Density Functional based Tight Binding combined with a Configuration Interaction (CI-DFTB) model and a hierarchical optimization scheme are also performed in the range n = 2-7 to determine the harmonic frequencies and a theoretical estimation of the dissociation energies. The frequencies are used in the calculations of the density of states needed in the PST simulations, assuming an extrapolation scheme for clusters larger than 7 units. Using the PST model with a minimal set of adjustable parameters, we obtain good fits of the experimental breakdown curves over the full studied size range. The approximations inherent to the PST simulation and the influence of the used parameters are carefully estimated. The derived dissociation energies show significant variations over the studied size range. Compared with neutral clusters, significantly higher values of the dissociation energies are obtained for the smaller sizes and attributed to charge resonance in line with CI-DFTB calculations.
Collapse
Affiliation(s)
- Sébastien Zamitha
- Laboratoire Collisions Agrégats Réactivité (LCAR/IRSAMC) UMR5589, Université de Toulouse and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Ming-Chao Ji
- Institut de Recherche en Astrophysique et Planétologie (IRAP) UMR5277, Université de Toulouse, CNRS, CNES, 9 avenue du Colonel Roche, F-31028 Toulouse, France
| | - Jean-Marc L’Hermite
- Laboratoire Collisions Agrégats Réactivité (LCAR/IRSAMC) UMR5589, Université de Toulouse and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie (IRAP) UMR5277, Université de Toulouse, CNRS, CNES, 9 avenue du Colonel Roche, F-31028 Toulouse, France
| | - Léo Dontot
- Institut de Recherche en Astrophysique et Planétologie (IRAP) UMR5277, Université de Toulouse, CNRS, CNES, 9 avenue du Colonel Roche, F-31028 Toulouse, France
- Laboratoire de Chimie et Physique Quantiques (LCPQ/IRSAMC) UMR5626, Université de Toulouse and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques (LCPQ/IRSAMC) UMR5626, Université de Toulouse and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantiques (LCPQ/IRSAMC) UMR5626, Université de Toulouse and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| |
Collapse
|
7
|
Chakraborty S, Mulas G, Demyk K, Joblin C. Experimental Approach to the Study of Anharmonicity in the Infrared Spectrum of Pyrene from 14 to 723 K. J Phys Chem A 2019; 123:4139-4148. [PMID: 31002512 PMCID: PMC6557715 DOI: 10.1021/acs.jpca.8b11016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Quantifying the effect of anharmonicity on the infrared spectrum of large molecules such as polycyclic aromatic hydrocarbons (PAHs) at high temperatures is the focus of a number of theoretical and experimental studies, many of them motivated by astrophysical applications. We recorded the IR spectrum of pyrene C16H10 microcrystals embedded in KBr pellets over a wide range of temperatures (14-723 K) and studied the evolution of band positions, widths, and integrated intensities with temperature. We identified jumps for some of the spectral characteristics of some bands in the 423-473 K range. These were attributed to a change of phase from crystal to molten in condensed pyrene, which appears to affect more strongly bands involving large CH motions. Empirical anharmonicity factors that quantify the linear evolution of band positions and widths with temperature for values larger than ∼150-250 K, depending on the band, were retrieved from both phases and averaged to provide recommended values for these anharmonicity factors. The derived values were found to be consistent with available gas phase data. We conclude about the relevance of the methodology to produce data that can be compared with calculated anharmonic IR spectra and provide input for models that simulate the IR emission of astro-PAHs.
Collapse
Affiliation(s)
- Shubhadip Chakraborty
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| | - Giacomo Mulas
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
- Istituto Nazionale di Astrofisica (INAF), Osservatorio Astronomico di Cagliari, 09047 Selargius (CA), Italy
| | - Karine Demyk
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| | - Christine Joblin
- Institut de Recherche en Astrophysique et Planétologie, Université de Toulouse, CNRS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| |
Collapse
|
8
|
Simon A, Rapacioli M, Michoulier E, Zheng L, Korchagina K, Cuny J. Contribution of the density-functional-based tight-binding scheme to the description of water clusters: methods, applications and extension to bulk systems. MOLECULAR SIMULATION 2018. [DOI: 10.1080/08927022.2018.1554903] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- A. Simon
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| | - M. Rapacioli
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| | - E. Michoulier
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
- Laboratoire Collisions Agrégats et Réactivité LCAR/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| | - L. Zheng
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| | - K. Korchagina
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| | - J. Cuny
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse and CNRS, Toulouse, France
| |
Collapse
|
9
|
Mulas G, Falvo C, Cassam-Chenaï P, Joblin C. Anharmonic vibrational spectroscopy of polycyclic aromatic hydrocarbons (PAHs). J Chem Phys 2018; 149:144102. [PMID: 30316271 DOI: 10.1063/1.5050087] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
While powerful techniques exist to accurately account for anharmonicity in vibrational molecular spectroscopy, they are computationally very expensive and cannot be routinely employed for large species and/or at non-zero vibrational temperatures. Motivated by the study of Polycyclic Aromatic Hydrocarbon (PAH) emission in space, we developed a new code, which takes into account all modes and can describe all infrared transitions including bands becoming active due to resonances as well as overtone, combination, and difference bands. In this article, we describe the methodology that was implemented and discuss how the main difficulties were overcome, so as to keep the problem tractable. Benchmarking with high-level calculations was performed on a small molecule. We carried out specific convergence tests on two prototypical PAHs, pyrene (C16H10) and coronene (C24H12), aiming at optimising tunable parameters to achieve both acceptable accuracy and computational costs for this class of molecules. We then report the results obtained at 0 K for pyrene and coronene, comparing the calculated spectra with available experimental data. The theoretical band positions were found to be significantly improved compared to harmonic density functional theory calculations. The band intensities are in reasonable agreement with experiments, the main limitation being the accuracy of the underlying calculations of the quartic force field. This is a first step toward calculating moderately high-temperature spectra of PAHs and other similarly rigid molecules using Monte Carlo sampling.
Collapse
Affiliation(s)
- Giacomo Mulas
- IRAP, Université de Toulouse, CNRS, UPS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| | - Cyril Falvo
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, University of Paris-Sud, Université Paris-Saclay, 91405 Orsay, France
| | | | - Christine Joblin
- IRAP, Université de Toulouse, CNRS, UPS, CNES, 9 Av. du Colonel Roche, 31028 Toulouse Cedex 4, France
| |
Collapse
|
10
|
Cuny J, Tarrat N, Spiegelman F, Huguenot A, Rapacioli M. Density-functional tight-binding approach for metal clusters, nanoparticles, surfaces and bulk: application to silver and gold. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:303001. [PMID: 29916820 DOI: 10.1088/1361-648x/aacd6c] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Density-functional based tight-binding (DFTB) is an efficient quantum mechanical method that can describe a variety of systems, going from organic and inorganic compounds to metallic and hybrid materials. The present topical review addresses the ability and performance of DFTB to investigate energetic, structural, spectroscopic and dynamical properties of gold and silver materials. After a brief overview of the theoretical basis of DFTB, its parametrization and its transferability, we report its past and recent applications to gold and silver systems, including small clusters, nanoparticles, bulk and surfaces, bare and interacting with various organic and inorganic compounds. The range of applications covered by those studies goes from plasmonics and molecular electronics, to energy conversion and surface chemistry. Finally, perspectives of DFTB in the field of gold and silver surfaces and NPs are outlined.
Collapse
Affiliation(s)
- Jérôme Cuny
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Université de Toulouse III [UPS] and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | | | | | | | | |
Collapse
|
11
|
Michoulier E, Ben Amor N, Rapacioli M, Noble JA, Mascetti J, Toubin C, Simon A. Theoretical determination of adsorption and ionisation energies of polycyclic aromatic hydrocarbons on water ice. Phys Chem Chem Phys 2018; 20:11941-11953. [PMID: 29667677 DOI: 10.1039/c8cp01175c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In dense interstellar environments, Polycyclic Aromatic Hydrocarbons (PAHs) are likely to condense onto or integrate into water ice mantles covering dust grains. Understanding the role of ice in the photo-induced processes involving adsorbed PAHs is therefore a key issue in astrochemistry. This requires (i) the knowledge of PAH-ice interactions, i.e. PAH-ice adsorption energies and local structures at the PAH-ice interface, as well as (ii) the understanding of the fate of electrons in the PAH-ice system upon excitation. Regarding (i), in this work, we determined the lowest energy structures of PAH-ice systems for a variety of PAHs ranging from naphthalene to ovalene on three types of ice - crystalline (Ih and Ic) and amorphous (low density) - using an explicit description of the electrons and a finite-sized system. The electronic structure was determined using the Self Consistent Charge Density Functional based Tight Binding (SCC-DFTB) scheme with modified Mulliken charges in order to ensure a good description of the studied systems. Regarding (ii), the influence of the interaction with ice on the Vertical Ionisation Potentials (VIPs) of the series of PAHs was determined using the constrained SCC-DFTB scheme benchmarked against correlated wavefunction results for PAH-(H2O)n (n = 1-6, 13) clusters. The results show a deviation equal, at most, to ∼1.4 eV of the VIPs of PAHs adsorbed on ice with respect to the gas phase values. Our results are discussed in the light of experimental data and previous theoretical studies.
Collapse
Affiliation(s)
- Eric Michoulier
- Lab. Chim. & Phys. Quant. LCPQ IRSAMC, Univ. Toulouse [UPS] UPS & CNRS, UMR5626, 118 Route Narbonne, F-31062, Toulouse, France.
| | | | | | | | | | | | | |
Collapse
|
12
|
Simon A, Noble JA, Rouaut G, Moudens A, Aupetit C, Iftner C, Mascetti J. Formation of coronene:water complexes: FTIR study in argon matrices and theoretical characterisation. Phys Chem Chem Phys 2017; 19:8516-8529. [DOI: 10.1039/c6cp08559h] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coronene preferentially forms σ-type rather than π-type complexes with water in low temperature argon matrices.
Collapse
Affiliation(s)
- A. Simon
- Laboratoire de Chimie et Physique Quantiques (LCPQ)
- IRSAMC
- UMR 5626 CNRS & Université Paul Sabatier
- 31062 Toulouse Cedex 09
- France
| | - J. A. Noble
- Institut des Sciences Moléculaires (ISM)
- Université de Bordeaux
- UMR 5255 CNRS
- 33405 Talence cedex
- France
| | - G. Rouaut
- Laboratoire de Chimie et Physique Quantiques (LCPQ)
- IRSAMC
- UMR 5626 CNRS & Université Paul Sabatier
- 31062 Toulouse Cedex 09
- France
| | - A. Moudens
- Institut des Sciences Moléculaires (ISM)
- Université de Bordeaux
- UMR 5255 CNRS
- 33405 Talence cedex
- France
| | - C. Aupetit
- Institut des Sciences Moléculaires (ISM)
- Université de Bordeaux
- UMR 5255 CNRS
- 33405 Talence cedex
- France
| | - C. Iftner
- Laboratoire de Chimie et Physique Quantiques (LCPQ)
- IRSAMC
- UMR 5626 CNRS & Université Paul Sabatier
- 31062 Toulouse Cedex 09
- France
| | - J. Mascetti
- Institut des Sciences Moléculaires (ISM)
- Université de Bordeaux
- UMR 5255 CNRS
- 33405 Talence cedex
- France
| |
Collapse
|
13
|
Gao J, Bouwman J, Berden G, Oomens J. The Influence of Metal Ion Binding on the IR Spectra of Nitrogen-Containing PAHs. J Phys Chem A 2016; 120:7800-7809. [DOI: 10.1021/acs.jpca.6b05060] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Juehan Gao
- Radboud
University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| | - Jordy Bouwman
- Radboud
University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| | - Giel Berden
- Radboud
University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
| | - Jos Oomens
- Radboud
University, FELIX Laboratory, Institute for Molecules and Materials, Toernooiveld 7c, 6525ED Nijmegen, The Netherlands
- Van’t
Hoff Institute for Molecular Sciences, University of Amsterdam, Science
Park 904, 1098XH Amsterdam, The Netherlands
| |
Collapse
|
14
|
Rapacioli M, Simon A, Marshall CCM, Cuny J, Kokkin D, Spiegelman F, Joblin C. Cationic Methylene-Pyrene Isomers and Isomerization Pathways: Finite Temperature Theoretical Studies. J Phys Chem A 2015; 119:12845-54. [PMID: 26600076 DOI: 10.1021/acs.jpca.5b09494] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This paper provides spectral characterizations of the two isomers of the 1-methylenepyrene cation, namely, the 1-pyrenemethylium and a pyrene-like isomer owing a tropylium cycle. Both are possible photodissociation products of the 1-methylpyrene cation and were proposed as potential contributors to the diffuse interstellar bands. In that respect, vibrational and electronic spectra are computed for the optimized structures at the density functional theory (DFT) and time-dependent (TD-)DFT levels. Finite temperature effects on these spectra are estimated from molecular dynamics simulations within the density functional-based tight-binding (DFTB) and TD-DFTB frameworks, these methods being first benchmarked against DFT and TD-DFT calculations. The computed spectra allow discrimination of the two isomers. When the temperature increases, bands are observed to redshift and merge. The isomerization mechanism is investigated with the metadynamics technique, a biased dynamics scheme allowing to probe reaction mechanisms with high energy barriers by investigating the free energy surface at various temperatures. Four pathways with similar barrier heights (3.5-4 eV) are found, showing that the interconversion process would only occur in interstellar clouds under photoactivation. The present study opens the way to simulations on larger methyl- and methylenePAHs of astrophysical interest and their experimental investigation.
Collapse
Affiliation(s)
- Mathias Rapacioli
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse (UPS) and CNRS , 118 Route de Narbonne, F-31062 Toulouse, France
| | - Aude Simon
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse (UPS) and CNRS , 118 Route de Narbonne, F-31062 Toulouse, France
| | - Charlotte C M Marshall
- Université de Toulouse, UPS-OMP, IRAP , 31400 Toulouse, France.,CNRS, IRAP , 9 Avenue du Colonel Roche, BP 44346-31028 Toulouse Cedex 4, France
| | - Jérôme Cuny
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse (UPS) and CNRS , 118 Route de Narbonne, F-31062 Toulouse, France
| | - Damian Kokkin
- Université de Toulouse, UPS-OMP, IRAP , 31400 Toulouse, France.,CNRS, IRAP , 9 Avenue du Colonel Roche, BP 44346-31028 Toulouse Cedex 4, France
| | - Fernand Spiegelman
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse (UPS) and CNRS , 118 Route de Narbonne, F-31062 Toulouse, France
| | - Christine Joblin
- Université de Toulouse, UPS-OMP, IRAP , 31400 Toulouse, France.,CNRS, IRAP , 9 Avenue du Colonel Roche, BP 44346-31028 Toulouse Cedex 4, France
| |
Collapse
|
15
|
Oliveira LFL, Cuny J, Morinière M, Dontot L, Simon A, Spiegelman F, Rapacioli M. Phase changes of the water hexamer and octamer in the gas phase and adsorbed on polycyclic aromatic hydrocarbons. Phys Chem Chem Phys 2015; 17:17079-89. [PMID: 26067775 DOI: 10.1039/c5cp02099a] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We investigate thermodynamic properties of small water clusters adsorbed on polycyclic aromatic hydrocarbons (PAHs), which are relevant systems in the context of astrophysical and atmospheric chemistry. We present heat capacity curves computed from parallel-tempering molecular dynamics and Monte Carlo simulations that were performed using the self-consistent-charge density-functional based tight-binding method. These curves are characteristic of the phase changes occurring in the aggregates and provide useful information on the evolution of the interaction between the water molecules and the PAHs as a function of temperature. After benchmarking our approach on the water hexamer and octamer in the gas phase, we present some results for these same clusters adsorbed on coronene and circumcoronene. When compared to the curves obtained for the isolated water clusters, the phase change temperature significantly decreases for the (H2O)8-PAH clusters whereas it depends on the nature of the PAH in the case of the hexamer. We analyse these differences as connected to the relative energies of the optimized characteristic isomers and to their dynamical behavior. We also evidence the population changes of the various cluster isomers as a function of temperature.
Collapse
Affiliation(s)
- Luiz Fernando L Oliveira
- Laboratoire de Chimie et Physique Quantiques LCPQ/IRSAMC, Université de Toulouse (UPS) and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France
| | | | | | | | | | | | | |
Collapse
|
16
|
Nishimura Y, Lee YP, Irle S, Witek HA. Critical interpretation of CH– and OH– stretching regions for infrared spectra of methanol clusters (CH3OH)n (n = 2–5) using self-consistent-charge density functional tight-binding molecular dynamics simulations. J Chem Phys 2014; 141:094303. [DOI: 10.1063/1.4893952] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Yoshifumi Nishimura
- Department of Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan
| | - Yuan-Pern Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, P.O. Box 23-166, Taipei 10617, Taiwan
| | - Stephan Irle
- Department of Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602, Japan
| | - Henryk A. Witek
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30010, Taiwan
| |
Collapse
|
17
|
Iftner C, Simon A, Korchagina K, Rapacioli M, Spiegelman F. A density functional tight binding/force field approach to the interaction of molecules with rare gas clusters: Application to (C6H6)+/0Arn clusters. J Chem Phys 2014; 140:034301. [DOI: 10.1063/1.4861431] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
18
|
Galué HÁ. Decoding the infrared signatures of pyramidal carbons in graphenic molecular nanostructures of interstellar origin. Chem Sci 2014. [DOI: 10.1039/c4sc00890a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
|
19
|
Simon A, Spiegelman F. Conformational dynamics and finite-temperature infrared spectra of the water octamer adsorbed on coronene. COMPUT THEOR CHEM 2013. [DOI: 10.1016/j.comptc.2013.06.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
20
|
Simon A, Spiegelman F. Water clusters adsorbed on polycyclic aromatic hydrocarbons: Energetics and conformational dynamics. J Chem Phys 2013; 138:194309. [DOI: 10.1063/1.4805015] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
21
|
Shojaei SHR, Morini F, Deleuze MS. Photoelectron and electron momentum spectroscopy of tetrahydrofuran from a molecular dynamical perspective. J Phys Chem A 2013; 117:1918-29. [PMID: 23387306 DOI: 10.1021/jp310722a] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The results of experimental studies of the valence electronic structure of tetrahydrofuran employing He I photoelectron spectroscopy as well as Electron Momentum Spectroscopy (EMS) have been reinterpreted on the basis of Molecular Dynamical simulations employing the classical MM3 force field and large-scale quantum mechanical simulations employing Born-Oppenheimer Molecular Dynamics in conjunction with the dispersion corrected ωB97XD exchange-correlation functional. Analysis of the produced atomic trajectories demonstrates the importance of thermal deviations from the lowest energy path for pseudorotation, in the form of considerable variations of the ring-puckering amplitude. These deviations are found to have a significant influence on several outer-valence electron momentum distributions, as well as on the He I photoelectron spectrum.
Collapse
Affiliation(s)
- S H Reza Shojaei
- Research Group of Theoretical Chemistry and Molecular Modelling, Hasselt University, Agoralaan Gebouw D, B-3590 Diepenbeek, Belgium
| | | | | |
Collapse
|
22
|
Electron momentum spectroscopy of metal carbonyls: a reinvestigation of the role of nuclear dynamics. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1244-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
23
|
Simon A, Rapacioli M, Mascetti J, Spiegelman F. Vibrational spectroscopy and molecular dynamics of water monomers and dimers adsorbed on polycyclic aromatic hydrocarbons. Phys Chem Chem Phys 2012; 14:6771-86. [PMID: 22495405 DOI: 10.1039/c2cp40321h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
This paper reports structures, energetics, dynamics and spectroscopy of H2O and (H2O)2 systems adsorbed on coronene (C24H12), a compact polycyclic aromatic hydrocarbon (PAH). On-the-fly Born-Oppenheimer molecular dynamics simulations are performed for temperatures T varying from 10 to 300 K, on a potential energy surface obtained within the self-consistent-charge density-functional based tight-binding (SCC-DFTB) approach. Anharmonic infrared (IR) spectra are extracted from these simulations. We first benchmark the SCC-DFTB semi-empirical hamiltonian vs. DFT (Density Functional Theory) calculations that include dispersion, on (C6H6)(H2O)1,2 small complexes. We find that charge corrections and inclusion of dispersion contributions in DFTB are necessary to obtain consistent structures, energetics and IR spectra. Using this Hamiltonian, the structures, energetics and IR features of the low-energy isomers of (C24H12)(H2O)1,2 are found to be similar to the DFT ones, with evidence for a stabilizing edge-coordination. The temperature dependence of the motions of H2O and (H2O)2 on the surface of C24H12 is analysed, revealing ultra-fast periodic motion. The water dimer starts diffusing at a higher temperature than the water monomer (150 K vs. 10 K respectively), which appears to be consistent with the binding energies. Qualitative and quantitative analyses of the effects of T on the IR spectra are performed. Anharmonic factors in particular are derived and it is shown that they can be used as signatures for the presence of PAH-water complexes. Finally, this paper lays the foundations for the studies of larger (PAH)m(H2O)n clusters, that can be treated with the efficient computational approach benchmarked in this paper.
Collapse
Affiliation(s)
- Aude Simon
- Laboratoire de Chimie et Physique Quantiques (LCPQ), Université de Toulouse [UPS] and CNRS, 118 Route de Narbonne, F-31062 Toulouse, France.
| | | | | | | |
Collapse
|
24
|
Simon A, Rapacioli M, Lanza M, Joalland B, Spiegelman F. Molecular dynamics simulations on [FePAH]+ π-complexes of astrophysical interest: anharmonic infrared spectroscopy. Phys Chem Chem Phys 2011; 13:3359-74. [PMID: 21243160 DOI: 10.1039/c0cp00990c] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this article, classical Born-Oppenheimer molecular dynamics (MD) simulations in the microcanonical ensemble are performed on neutral and cationic polycyclic aromatic hydrocarbon (PAH) species, focusing on [FePAH](+)π-complexes. Their anharmonic mid-infrared (mid-IR) spectra in the classical approximation are derived. This approach allows us to describe the influence of the energy of a system on its IR spectrum in terms of band-shifts and broadenings. The MD simulations are performed on a potential energy surface (PES) described at the self-consistent-charge density functional tight-binding level of theory. The PES is benchmarked on DFT calculations, showing the validity of the approach for complexes of Fe(+) with PAHs larger than coronene (C(24)H(12)) that are of astrophysical interest. MD simulations at high temperature show the occurrence of the diffusion of the Fe cation on the surface of the PAH. It proceeds through the edge of the carbon skeleton which is the lowest energy pathway presenting barriers smaller than 1 eV. Although only qualitative information on the band broadenings can be obtained, we show that the dependence of the computed positions of the main bands of [C(24)H(12)](0/+)and [FeC(24)H(12)](+)π-complexes on temperature can be fit by linear laws. The spectral trends determined for [FeC(24)H(12)](+) are compared to those of N-substituted [C(23)NH(12)](+)and [SiC(24)H(12)](+)π-complexes of astrophysical interest.
Collapse
Affiliation(s)
- Aude Simon
- Laboratoire de Chimie et Physique Quantiques, IRSAMC, Université de Toulouse, UPS, LCPQ, 118 Route de Narbonne, F-31062 Toulouse, France.
| | | | | | | | | |
Collapse
|