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Awali S, Mestdagh JM, Gaveau MA, Briant M, Soep B, Mazet V, Poisson L. Time-Resolved Observation of the Solvation Dynamics of a Rydberg Excited Molecule Deposited on an Argon Cluster. II. DABCO ☆ at Long Time Delays. J Phys Chem A 2021; 125:4341-4351. [PMID: 34003648 DOI: 10.1021/acs.jpca.1c01942] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The real-time dynamics of DABCO-argon clusters is investigated in a femtosecond pump-probe experiment where the pump excites DABCO to the S1 state within the argon cluster. The probe operates by photoionization and documents the energy and angular distributions of the resulting photoelectrons. The present work complements a previous work from our group [Awali Phys. Chem. Chem. Phys., 2014, 16, 516-526] where this dynamics was probed at short time, up to 4 ps after the pump pulse. Here, the dynamics is followed up to 500 ps. A multiscale dynamics is observed. It includes a jump between two solvation sites (time scale 0.27 ps) followed by the relaxation of the solvation cage excess vibrational energy (time scale 14 ps) and then by that of DABCO (time scale >150 ps). Polarization anisotropy, double polarization, and angular anisotropy effects are reported also. They are interpreted (quantitatively for the former effect) in terms of decoherence of rotational alignment, driven by the overall rotation of the DABCO-argon clusters. A tomographic view of the DABCO excited orbital, provided by the double anisotropy effect, is discussed on a qualitative basis.
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Affiliation(s)
- Slim Awali
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191, Gif-sur-Yvette, France.,EMIR, Institut Préparatoire aux Etudes d'Ingénieurs, 5019, Monastir, Tunisia
| | | | - Marc-André Gaveau
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191, Gif-sur-Yvette, France
| | - Marc Briant
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191, Gif-sur-Yvette, France
| | - Benoît Soep
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191, Gif-sur-Yvette, France.,Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, 91405, Orsay, France
| | - Vincent Mazet
- ICube, University of Strasbourg, CNRS, 300 boulevard Sébastien Brant, BP 10413, 67412 Illkirch, France
| | - Lionel Poisson
- Université Paris-Saclay, CEA, CNRS, LIDYL, 91191, Gif-sur-Yvette, France.,Institut des Sciences Moléculaires d'Orsay, Université Paris-Saclay, CNRS, 91405, Orsay, France
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Korenchenko AE, Gelchinski BR, Vorontsov AG. Statistical analysis of homogeneous nucleation of metallic nanoparticles during gas-phase synthesis. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:304002. [PMID: 32168496 DOI: 10.1088/1361-648x/ab7fd9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In this work, we set out to develop a model of gas-phase nucleation in a mixture of copper and argon atoms, which can be further used for analysing macro-systems. Processes occurring at the atomic level are described using coefficients obtained by statistical analysis of molecular dynamic (MD) data on interactions of metal clusters with metal and argon atoms. The MD simulation results are compared with those obtained using the proposed macroscopic model. It is found that the coefficients obtained by averaging the interaction data suitably represent the integral value of the heat of condensation, although result in the smoothing of the energy distribution functions of the clusters. Analysis of the evolution of the number of clusters has shown that the values of their increase rate were lower than those obtained by MD simulation. The conclusion is made, that in order to improve the precision of the developed gas-phase condensation model, it should be supplemented by cluster coagulation.
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Unn-Toc W, Halberstadt N, Meier C, Mella M. Exploring the importance of quantum effects in nucleation: the archetypical Ne(n) case. J Chem Phys 2012; 137:014304. [PMID: 22779645 DOI: 10.1063/1.4730033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The effect of quantum mechanics (QM) on the details of the nucleation process is explored employing Ne clusters as test cases due to their semi-quantal nature. In particular, we investigate the impact of quantum mechanics on both condensation and dissociation rates in the framework of the microcanonical ensemble. Using both classical trajectories and two semi-quantal approaches (zero point averaged dynamics, ZPAD, and Gaussian-based time dependent Hartree, G-TDH) to model cluster and collision dynamics, we simulate the dissociation and monomer capture for Ne(8) as a function of the cluster internal energy, impact parameter and collision speed. The results for the capture probability P(s)(b) as a function of the impact parameter suggest that classical trajectories always underestimate capture probabilities with respect to ZPAD, albeit at most by 15%-20% in the cases we studied. They also do so in some important situations when using G-TDH. More interestingly, dissociation rates k(diss) are grossly overestimated by classical mechanics, at least by one order of magnitude. We interpret both behaviours as mainly due to the reduced amount of kinetic energy available to a quantum cluster for a chosen total internal energy. We also find that the decrease in monomer dissociation energy due to zero point energy effects plays a key role in defining dissociation rates. In fact, semi-quantal and classical results for k(diss) seem to follow a common "corresponding states" behaviour when the proper definition of internal and dissociation energies are used in a transition state model estimation of the evaporation rate constants.
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Affiliation(s)
- Wesley Unn-Toc
- Laboratoire Collisions Agrégats Réactivité-IRSAMC, Université Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse, France
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Calvo F, Parneix P. Phase space theory of evaporation in neon clusters: the role of quantum effects. J Phys Chem A 2010; 113:14352-63. [PMID: 20028160 DOI: 10.1021/jp903282b] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Unimolecular evaporation of neon clusters containing between 14 and 148 atoms is theoretically investigated in the framework of phase space theory. Quantum effects are incorporated in the vibrational densities of states, which include both zero-point and anharmonic contributions, and in the possible tunneling through the centrifugal barrier. The evaporation rates, kinetic energy released, and product angular momentum are calculated as a function of excess energy or temperature in the parent cluster and compared to the classical results. Quantum fluctuations are found to generally increase both the kinetic energy released and the angular momentum of the product, but the effects on the rate constants depend nontrivially on the excess energy. These results are interpreted as due to the very few vibrational states available in the product cluster when described quantum mechanically. Because delocalization also leads to much narrower thermal energy distributions, the variations of evaporation observables as a function of canonical temperature appear much less marked than in the microcanonical ensemble. While quantum effects tend to smooth the caloric curve in the product cluster, the melting phase change clearly keeps a signature on these observables. The microcanonical temperature extracted from fitting the kinetic energy released distribution using an improved Arrhenius form further suggests a backbending in the quantum Ne(13) cluster that is absent in the classical system. Finally, in contrast to delocalization effects, quantum tunneling through the centrifugal barrier does not play any appreciable role on the evaporation kinetics of these rather heavy clusters.
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Affiliation(s)
- F Calvo
- LASIM, Université Claude Bernard Lyon 1 and CNRS UMR 5579, Bat. A. Kastler, 43 Bd du 11 novembre 1918, F69622 Villeurbanne, France
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Calvo F, Douady J. Stepwise hydration and evaporation of adenosine monophosphate nucleotide anions: a multiscale theoretical study. Phys Chem Chem Phys 2010; 12:3404-14. [PMID: 20336245 DOI: 10.1039/b923972c] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The structure and finite-temperature properties of hydrated nucleotide anion adenosine 5'-monophosphate (AMP) have been theoretically investigated with a variety of methods. Using a polarizable version of the Amber force field and replica-exchange molecular dynamics simulations, putative lowest-energy structures have been located for the AMP(-)(H(2)O)(n) cluster anions with n = 0-20. The hydration energies obtained with the molecular mechanics potential slightly overestimate experimental measurements. However, closer values are found after reoptimizing the structures locally at more sophisticated levels, namely semi-empirical (PM6) and density-functional theory (B3LYP/6-31+G*). Upon heating the complexes, various indicators such as the heat capacity, number of hydrogen bonds or surface area provide evidence that the water cluster melts below 200 K but remains bonded to the AMP anion. The sequential loss of water molecules after sudden heating has been studied using a statistical approach in which unimolecular evaporation is described using the orbiting transition state version of phase space theory, together with anharmonic densities of vibrational states. The evaporation rates are calibrated based on the results of molecular dynamics trajectories at high internal energy. Our results indicate that between 4 and 10 water molecules are lost from AMP(-)(H(2)O)(20) after one second depending on the initial heating in the 250-350 K range, with a concomitant cooling of the remaining cluster by 75-150 K.
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Affiliation(s)
- F Calvo
- LASIM, Université de Lyon and CNRS UMR 5579, Bât. A. Kastler, 43 Bd du 11 novembre 1918, F69622 Villeurbanne Cedex, France.
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Calvo F, Douady J, Spiegelman F. Accurate evaporation rates of pure and doped water clusters in vacuum: A statistico-dynamical approach. J Chem Phys 2010; 132:024305. [DOI: 10.1063/1.3280168] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Lubombo C, Curotto E, Janeiro Barral PE, Mella M. Thermodynamic properties of ammonia clusters (NH3)n n=2–11: Comparing classical and quantum simulation results for hydrogen bonded species. J Chem Phys 2009; 131:034312. [DOI: 10.1063/1.3159398] [Citation(s) in RCA: 19] [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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Calvo F, Parneix P, Basire M. Quantum densities of states of fluxional polyatomic systems from a superposition approximation. J Chem Phys 2009; 130:154101. [DOI: 10.1063/1.3115178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Calvo F, Díaz-Tendero S, Lebeault MA. Translational, rotational and vibrational energy partitioning in the sequential loss of carbon dimers from fullerenes. Phys Chem Chem Phys 2009; 11:6345-52. [DOI: 10.1039/b901557d] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Calvo F, Bonhommeau D, Parneix P. Multiscale dynamics of cluster fragmentation. PHYSICAL REVIEW LETTERS 2007; 99:083401. [PMID: 17930947 DOI: 10.1103/physrevlett.99.083401] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Indexed: 05/25/2023]
Abstract
The fragmentation of rare-gas clusters is theoretically investigated over time scales ranging from ionization and electronic excitation ( approximately fs) up to experimentally relevant times ( approximately ms). For this purpose a combination of methods are used, including nonadiabatic molecular dynamics, classical dynamics on the ground electronic state surface, and a kinetic description for the final evaporative cascade. The present multiscale protocol shows that, although the clusters are strongly out of equilibrium upon excitation, the long-time properties appear as statistical already after 1 ps.
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Affiliation(s)
- F Calvo
- Laboratoire de Chimie et Physique Quantiques, IRSAMC, Université Paul Sabatier, 118 Route de Narbonne, F31062, Toulouse Cedex, France.
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