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Balucani N, Caracciolo A, Vanuzzo G, Skouteris D, Rosi M, Pacifici L, Casavecchia P, Hickson KM, Loison JC, Dobrijevic M. An experimental and theoretical investigation of the N( 2D) + C 6H 6 (benzene) reaction with implications for the photochemical models of Titan. Faraday Discuss 2023; 245:327-351. [PMID: 37293920 DOI: 10.1039/d3fd00057e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report on a combined experimental and theoretical investigation of the N(2D) + C6H6 (benzene) reaction, which is of relevance in the aromatic chemistry of the atmosphere of Titan. Experimentally, the reaction was studied (i) under single-collision conditions by the crossed molecular beams (CMB) scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy (Ec) of 31.8 kJ mol-1 to determine the primary products, their branching fractions (BFs), and the reaction micromechanism, and (ii) in a continuous supersonic flow reactor to determine the rate constant as a function of temperature from 50 K to 296 K. Theoretically, electronic structure calculations of the doublet C6H6N potential energy surface (PES) were performed to assist the interpretation of the experimental results and characterize the overall reaction mechanism. The reaction is found to proceed via barrierless addition of N(2D) to the aromatic ring of C6H6, followed by formation of several cyclic (five-, six-, and seven-membered ring) and linear isomeric C6H6N intermediates that can undergo unimolecular decomposition to bimolecular products. Statistical estimates of product BFs on the theoretical PES were carried out under the conditions of the CMB experiments and at the temperatures relevant for Titan's atmosphere. In all conditions the ring-contraction channel leading to C5H5 (cyclopentadienyl) + HCN is dominant, while minor contributions come from the channels leading to o-C6H5N (o-N-cycloheptatriene radical) + H, C4H4N (pyrrolyl) + C2H2 (acetylene), C5H5CN (cyano-cyclopentadiene) + H, and p-C6H5N + H. Rate constants (which are close to the gas kinetic limit at all temperatures, with the recommended value of 2.19 ± 0.30 × 10-10 cm3 s-1 over the 50-296 K range) and BFs have been used in a photochemical model of Titan's atmosphere to simulate the effect of the title reaction on the species abundances as a function of the altitude.
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Affiliation(s)
- Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Adriana Caracciolo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | | | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06100, Perugia, Italy
| | - Leonardo Pacifici
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy.
| | - Kevin M Hickson
- Univ. Bordeaux, CNRS, Bordeaux INP, ISM, UMR 5255, F-33400 Talence, France
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Liang P, de Aragão EVF, Giani L, Mancini L, Pannacci G, Marchione D, Vanuzzo G, Faginas-Lago N, Rosi M, Skouteris D, Casavecchia P, Balucani N. OH( 2Π) + C 2H 4 Reaction: A Combined Crossed Molecular Beam and Theoretical Study. J Phys Chem A 2023. [PMID: 37207281 DOI: 10.1021/acs.jpca.2c08662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The reaction between the ground-state hydroxyl radical, OH(2Π), and ethylene, C2H4, has been investigated under single-collision conditions by the crossed molecular beam scattering technique with mass-spectrometric detection and time-of-flight analysis at the collision energy of 50.4 kJ/mol. Electronic structure calculations of the underlying potential energy surface (PES) and statistical Rice-Ramsperger-Kassel-Marcus (RRKM) calculations of product branching fractions on the derived PES for the addition pathway have been performed. The theoretical results indicate a temperature-dependent competition between the anti-/syn-CH2CHOH (vinyl alcohol) + H, CH3CHO (acetaldehyde) + H, and H2CO (formaldehyde) + CH3 product channels. The yield of the H-abstraction channel could not be quantified with the employed methods. The RRKM results predict that under our experimental conditions, the anti- and syn-CH2CHOH + H product channels account for 38% (in similar amounts) of the addition mechanism yield, the H2CO + CH3 channel for ∼58%, while the CH3CHO + H channel is formed in negligible amount (<4%). The implications for combustion and astrochemical environments are discussed.
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Affiliation(s)
- Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Emília Valença Ferreira de Aragão
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Master-Tec Srl, Via Sicilia, 41, Perugia 06128, Italy
| | - Lisa Giani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Université Grenoble Alpes, 621 Av. Centrale, Saint-Martin-d'Hères 38400, France
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Noelia Faginas-Lago
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
- Master-Tec Srl, Via Sicilia, 41, Perugia 06128, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile Ed Ambientale, Università Degli Studi di Perugia, Perugia 06125, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università Degli Studi di Perugia, Perugia 06123, Italy
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Vanuzzo G, Mancini L, Pannacci G, Liang P, Marchione D, Recio P, Tan Y, Rosi M, Skouteris D, Casavecchia P, Balucani N, Hickson KM, Loison JC, Dobrijevic M. Reaction N( 2D) + CH 2CCH 2 (Allene): An Experimental and Theoretical Investigation and Implications for the Photochemical Models of Titan. ACS Earth Space Chem 2022; 6:2305-2321. [PMID: 36303717 PMCID: PMC9589905 DOI: 10.1021/acsearthspacechem.2c00183] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 09/08/2022] [Accepted: 09/09/2022] [Indexed: 06/16/2023]
Abstract
We report on a combined experimental and theoretical investigation of the N(2D) + CH2CCH2 (allene) reaction of relevance in the atmospheric chemistry of Titan. Experimentally, the reaction was investigated (i) under single-collision conditions by the crossed molecular beams (CMB) scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy (E c) of 33 kJ/mol to determine the primary products and the reaction micromechanism and (ii) in a continuous supersonic flow reactor to determine the rate constant as a function of temperature from 50 to 296 K. Theoretically, electronic structure calculations of the doublet C3H4N potential energy surface (PES) were performed to assist the interpretation of the experimental results and characterize the overall reaction mechanism. The reaction is found to proceed via barrierless addition of N(2D) to one of the two equivalent carbon-carbon double bonds of CH2CCH2, followed by the formation of several cyclic and linear isomeric C3H4N intermediates that can undergo unimolecular decomposition to bimolecular products with elimination of H, CH3, HCN, HNC, and CN. The kinetic experiments confirm the barrierless nature of the reaction through the measurement of rate constants close to the gas-kinetic rate at all temperatures. Statistical estimates of product branching fractions (BFs) on the theoretical PES were carried out under the conditions of the CMB experiments at room temperature and at temperatures (94 and 175 K) relevant for Titan. Up to 14 competing product channels were statistically predicted with the main ones at E c = 33 kJ/mol being formation of cyclic-CH2C(N)CH + H (BF = 87.0%) followed by CHCCHNH + H (BF = 10.5%) and CH2CCNH + H (BF = 1.4%) the other 11 possible channels being negligible (BFs ranging from 0 to 0.5%). BFs under the other conditions are essentially unchanged. Experimental dynamical information could only be obtained on the overall H-displacement channel, while other possible channels could not be confirmed within the sensitivity of the method. This is also in line with theoretical predictions as the other possible channels are predicted to be negligible, including the HCN/HNC + C2H3 (vinyl) channels (overall BF < 1%). The dynamics and product distributions are dramatically different with respect to those observed in the isomeric reaction N(2D) + CH3CCH (propyne), where at a similar E c the main product channels are CH2NH (methanimine) + C2H (BF = 41%), c-C(N)CH + CH3 (BF = 32%), and CH2CHCN (vinyl cyanide) + H (BF = 12%). Rate coefficients (the recommended value is 1.7 (±0.2) × 10-10 cm3 s-1 over the 50-300 K range) and BFs have been used in a photochemical model of Titan's atmosphere to simulate the effect of the title reaction on the species abundance (including any new products formed) as a function of the altitude.
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Affiliation(s)
- Gianmarco Vanuzzo
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Yuxin Tan
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento
di Ingegneria Civile e Ambientale, Università
degli Studi di Perugia, 06100 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento
di Chimica, Biologia e Biotecnologie, Università
degli Studi di Perugia, 06123 Perugia, Italy
| | - Kevin M. Hickson
- Université
de Bordeaux, Institut des Sciences Moléculaires,
UMR 5255, F-33400 Talence, France
- CNRS,
Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
| | - Jean-Christophe Loison
- Université
de Bordeaux, Institut des Sciences Moléculaires,
UMR 5255, F-33400 Talence, France
- CNRS,
Institut des Sciences Moléculaires, UMR 5255, F-33400 Talence, France
| | - Michel Dobrijevic
- Laboratoire
d’Astrophysique de Bordeaux, Université
de Bordeaux, CNRS, B18N,
allée Geoffroy Saint-Hilaire, F-33615 Pessac, France
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Vanuzzo G, Marchione D, Mancini L, Liang P, Pannacci G, Recio P, Tan Y, Rosi M, Skouteris D, Casavecchia P, Balucani N. The N( 2D) + CH 2CHCN (Vinyl Cyanide) Reaction: A Combined Crossed Molecular Beam and Theoretical Study and Implications for the Atmosphere of Titan. J Phys Chem A 2022; 126:6110-6123. [PMID: 36053010 PMCID: PMC9483977 DOI: 10.1021/acs.jpca.2c04263] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The reaction of electronically excited nitrogen atoms,
N(2D), with vinyl cyanide, CH2CHCN, has been
investigated
under single-collision conditions by the crossed molecular beam (CMB)
scattering method with mass spectrometric detection and time-of-flight
(TOF) analysis at the collision energy, Ec, of 31.4 kJ/mol. Synergistic electronic structure calculations of
the doublet potential energy surface (PES) have been performed to
assist in the interpretation of the experimental results and characterize
the overall reaction micromechanism. Statistical (Rice–Ramsperger–Kassel–Marcus,
RRKM) calculations of product branching fractions (BFs) on the theoretical
PES have been carried out at different values of temperature, including
the one corresponding to the temperature (175 K) of Titan’s
stratosphere and at a total energy corresponding to the Ec of the CMB experiment. According to our theoretical
calculations, the reaction is found to proceed via barrierless addition
of N(2D) to the carbon–carbon double bond of CH2=CH–CN, followed by the formation of cyclic
and linear intermediates that can undergo H, CN, and HCN elimination.
In competition, the N(2D) addition to the CN group is also
possible via a submerged barrier, leading ultimately to N2 + C3H3 formation, the most exothermic of all
possible channels. Product angular and TOF distributions have been
recorded for the H-displacement channels leading to the formation
of a variety of possible C3H2N2 isomeric
products. Experimentally, no evidence of CN, HCN, and N2 forming channels was observed. These findings were corroborated
by the theory, which predicts a variety of competing product channels,
following N(2D) addition to the double bond, with the main
ones, at Ec = 31.4 kJ/mol, being six isomeric
H forming channels: c-CH(N)CHCN + H (BF = 35.0%), c-CHNCHCN + H (BF = 28.1%), CH2NCCN + H (BF =
26.3%), c-CH2(N)CCN(cyano-azirine) + H
(BF = 7.4%), trans-HNCCHCN + H (BF = 1.6%), and cis-HNCCHCN + H (BF = 1.3%), while C–C bond breaking
channels leading to c-CH2(N)CH(2H-azirine)
+ CN and c-CH2(N)C + HCN are predicted
to be negligible (0.02% and 0.2%, respectively). The highly exothermic
N2 + CH2CCH (propargyl) channel is also predicted
to be negligible because of the very high isomerization barrier from
the initial addition intermediate to the precursor intermediate able
to lead to products. The predicted product BFs are found to have,
in general, a very weak energy dependence. The above cyclic and linear
products containing an additional C–N bond could be potential
precursors of more complex, N-rich organic molecules that contribute
to the formation of the aerosols on Titan’s upper atmosphere.
Overall, the results are expected to have a significant impact on
the gas-phase chemistry of Titan’s atmosphere and should be
properly included in the photochemical models.
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Affiliation(s)
- Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Yuxin Tan
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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Marchione D, Mancini L, Liang P, Vanuzzo G, Pirani F, Skouteris D, Rosi M, Casavecchia P, Balucani N. Unsaturated Dinitriles Formation Routes in Extraterrestrial Environments: A Combined Experimental and Theoretical Investigation of the Reaction between Cyano Radicals and Cyanoethene (C 2H 3CN). J Phys Chem A 2022; 126:3569-3582. [PMID: 35640168 PMCID: PMC9189926 DOI: 10.1021/acs.jpca.2c01802] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The reaction between
cyano radicals (CN, X2Σ+) and cyanoethene
(C2H3CN) has been
investigated by a combined approach coupling crossed molecular beam
(CMB) experiments with mass spectrometric detection and time-of-flight
analysis at a collision energy of 44.6 kJ mol–1 and
electronic structure calculations to determine the relevant potential
energy surface. The experimental results can be interpreted by assuming
the occurrence of a dominant reaction pathway leading to the two but-2-enedinitrile
(1,2-dicyanothene) isomers (E- and Z-NC–CH=CH–CN) in a H-displacement channel and,
to a much minor extent, to 1,1-dicyanoethene, CH2C(CN)2. In order to derive the product branching ratios under the
conditions of the CMB experiments and at colder temperatures, including
those relevant to Titan and to cold interstellar clouds, we have carried
out RRKM statistical calculations using the relevant potential energy
surface of the investigated reaction. We have also estimated the rate
coefficient at very low temperatures by employing a semiempirical
method for the treatment of long-range interactions. The reaction
has been found to be barrierless and fast also under the low temperature
conditions of cold interstellar clouds and the atmosphere of Titan.
Astrophysical implications and comparison with literature data are
also presented. On the basis of the present work, 1,2-dicyanothene
and 1,1-dicyanothene are excellent candidates for the search of dinitriles
in the interstellar medium.
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Affiliation(s)
- Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Fernando Pirani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | | | - Marzio Rosi
- Dipartimento di Ingegneria Civile ed Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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Hixon KR, McKenzie JA, Sykes DAW, Yoneda S, Hensley A, Buettmann EG, Zheng H, Skouteris D, McAlinden A, Miller AN, Silva MJ. Ablation of Proliferating Osteoblast Lineage Cells After Fracture Leads to Atrophic Nonunion in a Mouse Model. J Bone Miner Res 2021; 36:2243-2257. [PMID: 34405443 PMCID: PMC8719642 DOI: 10.1002/jbmr.4424] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Revised: 07/15/2021] [Accepted: 08/10/2021] [Indexed: 01/19/2023]
Abstract
Nonunion is defined as the permanent failure of a fractured bone to heal, often necessitating surgical intervention. Atrophic nonunions are a subtype that are particularly difficult to treat. Animal models of atrophic nonunion are available; however, these require surgical or radiation-induced trauma to disrupt periosteal healing. These methods are invasive and not representative of many clinical nonunions where osseous regeneration has been arrested by a "failure of biology". We hypothesized that arresting osteoblast cell proliferation after fracture would lead to atrophic nonunion in mice. Using mice that express a thymidine kinase (tk) "suicide gene" driven by the 3.6Col1a1 promoter (Col1-tk), proliferating osteoblast lineage cells can be ablated upon exposure to the nucleoside analog ganciclovir (GCV). Wild-type (WT; control) and Col1-tk littermates were subjected to a full femur fracture and intramedullary fixation at 12 weeks age. We confirmed abundant tk+ cells in fracture callus of Col-tk mice dosed with water or GCV, specifically many osteoblasts, osteocytes, and chondrocytes at the cartilage-bone interface. Histologically, we observed altered callus composition in Col1-tk mice at 2 and 3 weeks postfracture, with significantly less bone and more fibrous tissue. Col1-tk mice, monitored for 12 weeks with in vivo radiographs and micro-computed tomography (μCT) scans, had delayed bone bridging and reduced callus size. After euthanasia, ex vivo μCT and histology showed failed union with residual bone fragments and fibrous tissue in Col1-tk mice. Biomechanical testing showed a failure to recover torsional strength in Col1-tk mice, in contrast to WT. Our data indicates that suppression of proliferating osteoblast-lineage cells for at least 2 weeks after fracture blunts the formation and remodeling of a mineralized callus leading to a functional nonunion. We propose this as a new murine model of atrophic nonunion. © 2021 American Society for Bone and Mineral Research (ASBMR).
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Affiliation(s)
- Katherine R Hixon
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Jennifer A McKenzie
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - David A W Sykes
- Department of Biology, Washington University in St. Louis, St. Louis, MO, USA
| | - Susumu Yoneda
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Austin Hensley
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Evan G Buettmann
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Hongjun Zheng
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Dimitrios Skouteris
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Audrey McAlinden
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA.,Department of Cell Biology & Physiology, Washington University in St. Louis, St. Louis, MO, USA.,St. Louis Shriners Hospital Research Center, Shriners Hospital for Children, St. Louis, MO, USA
| | - Anna N Miller
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA
| | - Matthew J Silva
- Department of Orthopaedic Surgery, Washington University in St. Louis, St. Louis, MO, USA.,Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, USA
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7
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Mancini L, Vanuzzo G, Marchione D, Pannacci G, Liang P, Recio P, Rosi M, Skouteris D, Casavecchia P, Balucani N. The Reaction N( 2D) + CH 3CCH (Methylacetylene): A Combined Crossed Molecular Beams and Theoretical Investigation and Implications for the Atmosphere of Titan. J Phys Chem A 2021; 125:8846-8859. [PMID: 34609869 PMCID: PMC8521525 DOI: 10.1021/acs.jpca.1c06537] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
The reaction of excited
nitrogen atoms N(2D) with CH3CCH (methylacetylene)
was investigated under single-collision
conditions by the crossed molecular beams (CMB) scattering method
with mass spectrometric detection and time-of-flight analysis at the
collision energy (Ec) of 31.0 kJ/mol.
Synergistic electronic structure calculations of the doublet potential
energy surface (PES) were performed to assist the interpretation of
the experimental results and characterize the overall reaction micromechanism.
Theoretically, the reaction is found to proceed via a barrierless addition of N(2D) to the carbon–carbon
triple bond of CH3CCH and an insertion of N(2D) into the CH bond of the methyl group, followed
by the formation of cyclic and linear intermediates that can undergo
H, CH3, and C2H elimination or isomerize to
other intermediates before unimolecularly decaying to a variety of
products. Kinetic calculations for addition and insertion mechanisms
and statistical (Rice-Ramsperger-Kassel-Marcus) computations of product
branching fractions (BFs) on the theoretical PES were performed at
different values of total energy, including the one corresponding
to the temperature (175 K) of Titan’s stratosphere and that
of the CMB experiment. Up to 14 competing product channels were statistically
predicted, with the main ones, at Ec =
31.0 kJ/mol, being the formation of CH2NH (methanimine)
+ C2H (ethylidyne) (BF = 0.41), c-C(N)CH
+ CH3 (BF = 0.32), CH2CHCN (acrylonitrile) +
H (BF = 0.12), and c-CH2C(N)CH + H (BF
= 0.04). Of the 14 possible channels, seven correspond to H displacement
channels of different exothermicity, for a total H channel BF of ∼0.25
at Ec = 31.0 kJ/mol. Experimentally, dynamical
information could only be obtained about the overall H channels. In
particular, the experiment corroborates the formation of acrylonitrile
+ H, which is the most exothermic of all 14 reaction channels and
is theoretically calculated to be the dominant H-forming channel (BF
= 0.12). The products containing a novel C–N bond could be
potential precursors to form other nitriles (C2N2, C3N) or more complex organic species containing N atoms
in planetary atmospheres, such as those of Titan and Pluto. Overall,
the results are expected to have a potentially significant impact
on the understanding of the gas-phase chemistry of Titan’s
atmosphere and the modeling of that atmosphere.
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Affiliation(s)
- Luca Mancini
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Gianmarco Vanuzzo
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Demian Marchione
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Giacomo Pannacci
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pengxiao Liang
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Pedro Recio
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Marzio Rosi
- Dipartimento di Ingegneria Civile e Ambientale, Università degli Studi di Perugia, 06125 Perugia, Italy
| | | | - Piergiorgio Casavecchia
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - Nadia Balucani
- Dipartimento di Chimica, Biologia e Biotecnologie, Università degli Studi di Perugia, 06123 Perugia, Italy
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8
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Abstract
BACKGROUND More than 450,000 rotator cuff repairs are performed annually, yet healing of tendon to bone often fails. This failure is rooted in the fibrovascular healing response, which does not regenerate the native attachment site. Better healing outcomes may be achieved by targeting inflammation during the early period after repair. Rather than broad inhibition of inflammation, which may impair healing, the current study utilized a molecularly targeted approach to suppress IKKβ, shutting down only the inflammatory arm of the nuclear factor κB (NF-κB) signaling pathway. PURPOSE To evaluate the therapeutic potential of IKKβ inhibition in a clinically relevant model of rat rotator cuff repair. STUDY DESIGN Controlled laboratory study. METHODS After validating the efficacy of the IKKβ inhibitor in vitro, it was administered orally once a day for 7 days after surgery in a rat rotator cuff repair model. The effect of treatment on reducing inflammation and improving repair quality was evaluated after 3 days and 2, 4, and 8 weeks of healing, using gene expression, biomechanics, bone morphometry, and histology. RESULTS Inhibition of IKKβ attenuated cytokine and chemokine production in vitro, demonstrating the potential for this inhibitor to reduce inflammation in vivo. Oral treatment with IKKβ inhibitor reduced NF-κB target gene expression by up to 80% compared with a nontreated group at day 3, with a subset of these genes suppressed through 14 days. Furthermore, the IKKβ inhibitor led to enhanced tenogenesis and extracellular matrix production, as demonstrated by gene expression and histological analyses. At 4 weeks, inhibitor treatment led to increased toughness, no effects on failure load and strength, and decreases in stiffness and modulus when compared with vehicle control. At 8 weeks, IKKβ inhibitor treatment led to increased toughness, failure load, and strength compared with control animals. IKKβ inhibitor treatment prevented the bone loss near the tendon attachment that occurred in repairs in control. CONCLUSION Pharmacological inhibition of IKKβ successfully suppressed excessive inflammation and enhanced tendon-to-bone healing after rotator cuff repair in a rat model. CLINICAL RELEVANCE The NF-κB pathway is a promising target for enhancing outcomes after rotator cuff repair.
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Affiliation(s)
- Mikhail Golman
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Xiaoning Li
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Dimitrios Skouteris
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Adam A. Abraham
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Lee Song
- Department of Orthopedic Surgery, Columbia University, New York, New York, USA
| | - Yousef Abu-Amer
- Department of Orthopaedic Surgery, Washington University, St Louis, Missouri, USA
| | - Stavros Thomopoulos
- Department of Biomedical Engineering, Columbia University, New York, New York, USA.,Department of Orthopedic Surgery, Columbia University, New York, New York, USA.,Address correspondence to Stavros Thomopoulos, PhD, Carroll Laboratories of Orthopedic Research, Columbia University, Black Building, Room 1408, 650 W 168 St, New York, NY 10032-3702, USA () (Twitter: @ThomopoulosLab)
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9
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Skouteris D, Thoma S, Andritsos G, Tasios N, Praxitelous P, Psychoyios V. Simultaneous Compression of the Median and Ulnar Nerve at the Elbow: A Retrospective Study. J Hand Surg Asian Pac Vol 2018; 23:198-204. [PMID: 29734905 DOI: 10.1142/s2424835518500200] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND Simultaneous compression of the median and ulnar nerve at the elbow region has not been sufficiently highlighted in the literature. The purposes of the present study are to report our experience regarding this entity, to elucidate the clinical features, and to describe the operative technique and findings as well as the results of simultaneous decompression performed through the same medial incision. METHODS We performed a retrospective study of thirteen elbows in thirteen patients -nine men and four women- with simultaneous compression of the median and ulnar nerve at the elbow region between 2000 and 2011. All were manual workers. Diagnosis was largely based on symptoms, patterns of paresthesia, and specific tests. Surgical decompression of both nerves at the same time was performed through a single anteromedial incision creating large flaps. RESULTS Patients were followed for a mean of thirty-eight months (range seven to ninety six). Resting pain in the proximal forearm as well as sudden onset of numbness in the ring and little fingers were reported by all patients. Nerve conduction studies were positive only for cubital tunnel syndrome. In all patients symptoms subsided following surgical decompression. At the time of final follow up there is no evidence of recurrence. CONCLUSIONS Proximal median nerve compression can be seen in association with cubital tunnel syndrome. Careful evaluation of the reported symptoms as well as thorough clinical examination are the keystone of the correct diagnosis. Also, on the basis of this study, we believe that concurrent decompression can be performed through a single medial incision, though extensive dissection may be required.
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Affiliation(s)
- Dimitrios Skouteris
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
| | - Sofia Thoma
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
| | - Georgios Andritsos
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
| | - Nikolaos Tasios
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
| | - Praxitelis Praxitelous
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
| | - Vassilios Psychoyios
- * 5th Orthopaedic Department, Hand and Upper Extremity Service, Asklepieion Voulas General Hospital, Athens, Greece
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10
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Rosi M, Mancini L, Skouteris D, Ceccarelli C, Faginas Lago N, Podio L, Codella C, Lefloch B, Balucani N. Possible scenarios for SiS formation in the interstellar medium: Electronic structure calculations of the potential energy surfaces for the reactions of the SiH radical with atomic sulphur and S2. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.01.053] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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11
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Sleiman C, El Dib G, Rosi M, Skouteris D, Balucani N, Canosa A. Low temperature kinetics and theoretical studies of the reaction CN + CH 3NH 2: a potential source of cyanamide and methyl cyanamide in the interstellar medium. Phys Chem Chem Phys 2018; 20:5478-5489. [PMID: 29082409 DOI: 10.1039/c7cp05746f] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reaction between cyano radicals (which are ubiquitous in interstellar clouds) and methylamine (a molecule detected in various interstellar sources) has been investigated in a synergistic experimental and theoretical study. The reaction has been found to be very fast in the entire range of temperatures investigated (23-297 K) by using a CRESU apparatus coupled to pulsed laser photolysis - laser induced fluorescence. The global experimental rate coefficient is given by In addition, dedicated electronic structure calculations of the underlying potential energy surface have been performed, together with capture theory and RRKM calculations. The experimental data have been interpreted in the light of the theoretical calculations and the product branching ratio has been established. According to the present study, in the range of temperatures investigated the title reaction is an efficient interstellar route of formation of cyanamide, NH2CN, another interstellar species. The second most important channel is the one leading to methyl cyanamide, CH3NHCN (an isomer of aminoacetonitrile), via a CN/H exchange mechanism with a yield of 12% of the global reaction in the entire range of temperatures explored. For a possible inclusion in future astrochemical models we suggest, by referring to the usual expression the following values: α = 3.68 × 10-12 cm3 molec-1 s-1, β = -1.80, γ = 7.79 K for the channel leading to NH2CN + CH3; α = 5.05 × 10-13 cm3 molec-1 s-1, β = -1.82, γ = 7.93 K for the channel leading to CH3NHCN + H.
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Affiliation(s)
- Chantal Sleiman
- Institut de Physique de Rennes, UMR 6251 du CNRS - Université de Rennes 1, Bat. 11C, Campus de Beaulieu, 263 Avenue du Général Leclerc, F-35042 Rennes Cedex, France.
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12
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Skouteris D, Magnissalis E, Papalois A, Varitimidis S, Papagelopoulos PJ, Zoubos AB. An Experimental Model on the Biomechanical Behaviour of the Flexor Tendons in New Zealand Rabbits. J Hand Surg Asian Pac Vol 2017; 22:320-328. [PMID: 28774241 DOI: 10.1142/s021881041750037x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
BACKGROUND In order to introduce new pharmacological agents with the intent to inhibit the adhesion formation, it is important to test such products on laboratory animals under a protocol that can evaluate the quantitative and qualitative aspects of healing of the tendons. Most experimental models focus on the tensile strength and histological analysis of the tendons, failing to sufficiently quantify the degree of the adhesion formation. METHODS The experiment included six male New Zealand rabbits that underwent surgery of their right forepaws. The deep flexor tendon of the middle finger was transected and repaired and after six weeks the rabbits were killed. In order to assess the extent of adhesions, the functional stiffness of the tendons and the range of motion of the specimens' fingers was studied using a tensile testing machine. The setup used allowed the simultaneous recording of the specimens' motion and the pulling force values. RESULTS The mean values of the left and right forepaws were expressed in the same chart showing a clear difference between the operated and non operated forepaws. CONCLUSIONS Using a relatively simple set up in the laboratory we had the chance to focus on a more elaborate analysis of the data with the help of low cost and accessible software.
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Affiliation(s)
- D Skouteris
- * 5th Orthopaedic Department, "Asklepieion Voulas" General Hospital, Athens, Greece
| | | | - A Papalois
- ‡ ELPEN Research & Experimental Center, Athens, Greece
| | - S Varitimidis
- § Department of Orthopaedic Surgery, University of Thessaly, Larissa, Greece
| | - P J Papagelopoulos
- ∥ 1st Orthopaedic Department, Orthopaedic Research and Education Center (OREC) University Hospital "Attikon", National & Kapodistrian University of Athens, School of Medicine, Athens, Greece
| | - A B Zoubos
- ∥ 1st Orthopaedic Department, Orthopaedic Research and Education Center (OREC) University Hospital "Attikon", National & Kapodistrian University of Athens, School of Medicine, Athens, Greece
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13
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Banerjee S, Skouteris D, Barone V. A diabatic electronic state system to describe the internal conversion of azulene. Comput Sci Appl 2017; 10408:328-337. [PMID: 31032486 PMCID: PMC6485616 DOI: 10.1007/978-3-319-62404-4_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A diabatic system of two electronic potential energy surfaces as well as the coupling between them is presented. The system is to be used to study the dynamics of the S1 → S0 internal conversion of azulene and is based on single point calculations of the minima of the two surfaces and a dipole-quadrupole (DQ) diabatization. Based on this, a couple of harmonic diabatic surfaces together with a linear coupling surface have been devised. Some preliminary dynamics results are shown.
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14
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Skouteris D, Vazart F, Ceccarelli C, Balucani N, Puzzarini C, Barone V. New quantum chemical computations of formamide deuteration support a gas-phase formation of this prebiotic molecule. ACTA ACUST UNITED AC 2017. [DOI: 10.1093/mnrasl/slx012] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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15
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Vazart F, Calderini D, Puzzarini C, Skouteris D, Barone V. State-of-the-Art Thermochemical and Kinetic Computations for Astrochemical Complex Organic Molecules: Formamide Formation in Cold Interstellar Clouds as a Case Study. J Chem Theory Comput 2016; 12:5385-5397. [PMID: 27689448 PMCID: PMC5856337 DOI: 10.1021/acs.jctc.6b00379] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We describe an integrated computational strategy aimed at providing reliable thermochemical and kinetic information on the formation processes of astrochemical complex organic molecules. The approach involves state-of-the-art quantum-mechanical computations, second-order vibrational perturbation theory, and kinetic models based on capture and transition state theory together with the master equation approach. Notably, tunneling, quantum reflection, and leading anharmonic contributions are accounted for in our model. Formamide has been selected as a case study in view of its interest as a precursor in the abiotic amino acid synthesis. After validation of the level of theory chosen for describing the potential energy surface, we have investigated several pathways of the OH + CH2NH and NH2 + H2CO reaction channels. Our results show that both reaction channels are essentially barrierless (in the sense that all relevant transition states lie below or only marginally above the reactants) and once tunneling is taken into the proper account indicate that the reaction can occur under the low temperature conditions of interstellar environments.
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Affiliation(s)
- Fanny Vazart
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Danilo Calderini
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Cristina Puzzarini
- Dipartimento di Chimica "Giacomo Ciamician", Via F. Selmi 2, 40126 Bologna, Italy
| | | | - Vincenzo Barone
- Scuola Normale Superiore, piazza dei Cavalieri 7, 56125 Pisa, Italy
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16
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Abstract
We present a calculation of the torsional potential of the three metallocenes of the iron group, that is, ferrocene, ruthenocene, and osmocene, calculated with the GAUSSIAN program suite. Both a variational method (through computation of the exact energy levels) and our Chebyshev imaginary time propagation method are used to calculate the hindered rotation partition function, demonstrating the efficiency of the Chebyshev scheme. The transition from a semirigid through a hindered rotor to the free rotor regime is demonstrated, and the effect of the hindered rotation (as opposed to a harmonic) treatment on the thermodynamics of metallocenes is demonstrated.
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Affiliation(s)
| | - D Calderini
- Scuola Normale Superiore , Piazza dei Cavalieri 7, Pisa 56126, Italy.,Istituto Nazionale di Fisica Nucleare (INFN) sezione di Pisa , Largo Bruno Pontecorvo 3, 56127, Pisa, Italy
| | - D Skouteris
- Scuola Normale Superiore , Piazza dei Cavalieri 7, Pisa 56126, Italy
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17
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Abstract
We report in the present paper a comprehensive investigation of representative Pt(II) and Ir(III) complexes with special reference to their one-photon absorption spectra employing methods rooted in density functional theory and its time dependent extension. We have compared nine different functionals ranging from generalized gradient approximation (GGA) to global or range-separated hybrids, and two different basis sets, including pseudopotentials for 4 iridium and 7 platinum complexes. It turns out that hybrid functionals with the same exchange part give comparable results irrespective of the specific correlation functional (i.e., B3LYP is very close to B3PW91 and PBE0 is very close to MPW1PW91). More recent functionals, such as CAM-B3LYP and M06-2X, overestimate excitation energies, whereas local functionals (BP86 -GGA-, M06-L -Meta GGA-) strongly underestimate transition energies with respect to experimental results. As expected, basis set effects are weak, and the use of a triple-ζ polarized (def2-TZVP) basis set does not significantly improve the computed excitation energies with respect to a classical double-ζ basis set (LANL2DZ) augmented by polarization functions, but it significantly raises the computational effort.
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Affiliation(s)
- Camille Latouche
- Scuola Normale Superiore , Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | | | | | - Vincenzo Barone
- Scuola Normale Superiore , Piazza dei Cavalieri 7, 56126 Pisa, Italy
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18
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Skouteris D, Calderini D, Barone V. Methods for Calculating Partition Functions of Molecules Involving Large Amplitude and/or Anharmonic Motions. J Chem Theory Comput 2016; 12:1011-8. [PMID: 26765363 DOI: 10.1021/acs.jctc.5b01094] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We present a method for calculating partition functions taking into account anharmonic contributions for systems involving both small-amplitude vibrations and hindered rotations. The Wang-Landau scheme is used in the first case, while two alternative schemes are used for hindered rotation based on imaginary time propagation and fitting of the exact energy levels as a function of quantum number. These two schemes are shown to be complementary in their ranges of applicability (in terms of the torsional rotational constant and the relevant potential). Partition functions for four different molecules are calculated and compared to simpler ones obtained using a harmonic model.
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Affiliation(s)
- D Skouteris
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | - D Calderini
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy.,Istituto Nazionale di Fisica Nucleare (INFN) sezione di Pisa, Largo Bruno Pontecorvo, 3, 56127 Pisa, Italy
| | - V Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
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19
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Vazart F, Latouche C, Skouteris D, Balucani N, Barone V. CYANOMETHANIMINE ISOMERS IN COLD INTERSTELLAR CLOUDS: INSIGHTS FROM ELECTRONIC STRUCTURE AND KINETIC CALCULATIONS. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/810/2/111] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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20
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Skouteris D, Barone V. Nonadiabatic photodynamics of phenol on a realistic potential energy surface by a novel multilayer Gaussian MCTDH program. Chem Phys Lett 2015; 636:15-21. [PMID: 29551833 DOI: 10.1016/j.cplett.2015.06.065] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the main features of a new implementation of the Gaussian Multi-Configuration Time-Dependent Hartree (G-MCTDH) model. The code allows effective computations of time-dependent phenomena, including calculation of vibronic spectra (in one or more electronic states), relative state populations etc., with the possibility of a multilayer formulation. We have validated the code on the diabatic surfaces recently published by Truhlar and coworkers to study the nonadiabatic photodynamics of phenol. Using an Ehrenfest-like, single-nuclear-configuration (but in a fully quantum formalism) model we calculate the optical spectrum and relative state populations of the system as a function of time.
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Affiliation(s)
- D Skouteris
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - V Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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21
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Barone V, Latouche C, Skouteris D, Vazart F, Balucani N, Ceccarelli C, Lefloch B. Gas-phase formation of the prebiotic molecule formamide: insights from new quantum computations. ACTA ACUST UNITED AC 2015. [DOI: 10.1093/mnrasl/slv094] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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22
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Vazart F, Calderini D, Skouteris D, Latouche C, Barone V. Reassessment of the Thermodynamic, Kinetic, and Spectroscopic Features of Cyanomethanimine Derivatives: A Full Anharmonic Perturbative Treatment. J Chem Theory Comput 2015; 11:1165-71. [PMID: 26579765 DOI: 10.1021/ct501147a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Herein we report a full thermodynamic and vibrational investigation of C-cyanomethanimine isomers rooted into the Density Functional Theory (DFT) and the second-order vibrational perturbation theory (VPT2). We show that an anharmonic treatment affects dramatically the vibrational behavior of the molecules, especially thanks to the inclusion of interaction terms between the various modes. Furthermore, the equilibrium constant between the isomers, as well as the rate constant, have been obtained at both harmonic and anharmonic levels showing, as expected, slight but non-negligible differences. To support our investigation, dispersion effects have been employed.
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Affiliation(s)
- Fanny Vazart
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
| | - Danilo Calderini
- Scuola Normale Superiore , piazza dei Cavalieri 7, 56125 Pisa, Italy
| | | | - Camille Latouche
- 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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23
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Latouche C, Palazzetti F, Skouteris D, Barone V. High-Accuracy Vibrational Computations for Transition-Metal Complexes Including Anharmonic Corrections: Ferrocene, Ruthenocene, and Osmocene as Test Cases. J Chem Theory Comput 2014; 10:4565-73. [DOI: 10.1021/ct5006246] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Camille Latouche
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
| | | | | | - Vincenzo Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, 56126 Pisa, Italy
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24
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Skouteris D, Barone V. A new Gaussian MCTDH program: implementation and validation on the levels of the water and glycine molecules. J Chem Phys 2014; 140:244104. [PMID: 24985615 DOI: 10.1063/1.4883677] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We report the main features of a new general implementation of the Gaussian Multi-Configuration Time-Dependent Hartree model. The code allows effective computations of time-dependent phenomena, including calculation of vibronic spectra (in one or more electronic states), relative state populations, etc. Moreover, by expressing the Dirac-Frenkel variational principle in terms of an effective Hamiltonian, we are able to provide a new reliable estimate of the representation error. After validating the code on simple one-dimensional systems, we analyze the harmonic and anharmonic vibrational spectra of water and glycine showing that reliable and converged energy levels can be obtained with reasonable computing resources. The data obtained on water and glycine are compared with results of previous calculations using the vibrational second-order perturbation theory method. Additional features and perspectives are also shortly discussed.
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Affiliation(s)
- D Skouteris
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
| | - V Barone
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy
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25
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26
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Leonori F, Skouteris D, Petrucci R, Casavecchia P, Rosi M, Balucani N. Combined crossed beam and theoretical studies of the C(1D) + CH4 reaction. J Chem Phys 2013; 138:024311. [DOI: 10.1063/1.4773579] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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27
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Balucani N, Skouteris D, Leonori F, Petrucci R, Hamberg M, Geppert WD, Casavecchia P, Rosi M. Combined crossed beam and theoretical studies of the N(2D) + C2H4 reaction and implications for atmospheric models of Titan. J Phys Chem A 2012; 116:10467-79. [PMID: 23016665 DOI: 10.1021/jp3072316] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The dynamics of the H displacement channels in the reaction N((2)D) + C(2)H(4) have been investigated by the crossed molecular beam technique with mass spectrometric detection and time-of-flight analysis at two different collision energies (17.2 and 28.2 kJ/mol). The interpretation of the scattering results is assisted by new electronic structure calculations of stationary points and product energetics for the C(2)H(4)N ground state doublet potential energy surface. RRKM statistical calculations have been performed to derive the product branching ratio under the conditions of the present experiments and of the atmosphere of Titan. Similarities and differences with respect to a recent study performed in crossed beam experiments coupled to ionization via tunable VUV synchrotron radiation are discussed (Lee, S.-H.; et al. Phys. Chem. Chem. Phys.2011, 13, 8515-8525). Implications for the atmospheric chemistry of Titan are presented.
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Affiliation(s)
- Nadia Balucani
- Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy.
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Vila HVR, Leal LA, Martins JBL, Skouteris D, e Silva GM, Gargano R. The H + Li2 bimolecular exchange reaction: Dynamical and kinetical properties at J = 0. J Chem Phys 2012; 136:134319. [DOI: 10.1063/1.3700164] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Skouteris D, De Fazio D, Cavalli S, Aquilanti V. Quantum Stereodynamics for the Two Product Channels of the F + HD Reaction from the Complete Scattering Matrix in the Stereodirected Representation. J Phys Chem A 2009; 113:14807-12. [PMID: 19761272 DOI: 10.1021/jp904972n] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- D. Skouteris
- Dipartimento di Matematica e Informatica, Università degli Studi di Perugia, 06123 Perugia, Italy, Istituto di Metodologie Inorganiche e dei Plasmi, CNR, 00016 Roma, Italy, and Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - D. De Fazio
- Dipartimento di Matematica e Informatica, Università degli Studi di Perugia, 06123 Perugia, Italy, Istituto di Metodologie Inorganiche e dei Plasmi, CNR, 00016 Roma, Italy, and Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - S. Cavalli
- Dipartimento di Matematica e Informatica, Università degli Studi di Perugia, 06123 Perugia, Italy, Istituto di Metodologie Inorganiche e dei Plasmi, CNR, 00016 Roma, Italy, and Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy
| | - V. Aquilanti
- Dipartimento di Matematica e Informatica, Università degli Studi di Perugia, 06123 Perugia, Italy, Istituto di Metodologie Inorganiche e dei Plasmi, CNR, 00016 Roma, Italy, and Dipartimento di Chimica, Università degli Studi di Perugia, 06123 Perugia, Italy
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Garcia E, Saracibar A, Laganà A, Skouteris D. The shape of the potential energy surface and the thermal rate coefficients of the N + N2 reaction. J Phys Chem A 2007; 111:10362-8. [PMID: 17658770 DOI: 10.1021/jp072345a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Full-dimensional quantum time-dependent calculations of the detailed probabilities of the N + N2 reaction have been performed on different potential energy surfaces, initial quantum states, and total angular momentum quantum numbers. The calculations allowed a rationalization of the effect of both moving the saddle to reaction out of collinearity and lowering its height. On some of these surfaces, more extended studies of the reactive dynamics of the system were performed. On one of them also, thermal rate coefficients were computed using J = 0 quantum probabilities and the J-shift model after testing the applicability of such a model against centrifugal sudden results. A comparison of the calculated thermal rate coefficients with theoretical and experimental data available from the literature is also made, and possible effects of inserting an intermediate well at the top of the saddle are argued.
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Affiliation(s)
- E Garcia
- Departamento de Quimica Fisica, Universidad del Pais Vasco, Vitoria, Spain
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Balucani N, Skouteris D, Cartechini L, Capozza G, Segoloni E, Casavecchia P, Alexander MH, Capecchi G, Werner HJ. Differential cross sections from quantum calculations on coupled Ab initio potential energy surfaces and scattering experiments for Cl(2P)+H2 reactions. Phys Rev Lett 2003; 91:013201. [PMID: 12906538 DOI: 10.1103/physrevlett.91.013201] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2003] [Indexed: 05/24/2023]
Abstract
To assess the relative reactivity of the spin-orbit excited state of atomic Cl with molecular hydrogen, we have measured differential cross sections using an atomic Cl beam with a known concentration of the ground and excited spin-orbit states. These are compared with the first determination of the cross sections from quantum mechanical scattering calculations on a set of coupled ab initio potential energy surfaces. The comparison suggests that these surfaces may underestimate the degree of rotational excitation of the HCl products and that the excited spin-orbit state plays a minor role in the reaction.
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Affiliation(s)
- N Balucani
- Dipartimento di Chimica, Università di Perugia, 06123 Perugia, Italy
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32
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Aoiz FJ, Bañares L, Castillo JF, Menéndez M, Skouteris D, Werner HJ. A quantum mechanical and quasi-classical trajectory study of the Cl+H2 reaction and its isotopic variants: Dependence of the integral cross section on the collision energy and reagent rotation. J Chem Phys 2001. [DOI: 10.1063/1.1385155] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Skodje RT, Skouteris D, Manolopoulos DE, Lee SH, Dong F, Liu K. Resonance-mediated chemical reaction: F+HD-->HF+D. Phys Rev Lett 2000; 85:1206-1209. [PMID: 10991513 DOI: 10.1103/physrevlett.85.1206] [Citation(s) in RCA: 189] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2000] [Indexed: 05/23/2023]
Abstract
Conclusive evidence is presented for the existence of a reactive resonance in the F+HD reaction. In a molecular beam experiment, the resonance appears in the integral cross section as a distinct steplike feature, while in the differential cross section it is manifested as sharply varying forward-backward peaks in the product distribution. A detailed analysis of the quantum dynamics establishes that a reactive resonance localized in the transition-state region is responsible for these remarkable observations. At collision energies below 1 kcal/mol, the reaction proceeds almost exclusively through resonant tunneling with very little contribution from the more conventional direct mechanism.
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Affiliation(s)
- RT Skodje
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan 106, Republic of China and Department of Chemistry, University of Colorado, Boulder, Colorado 80309
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Abstract
The van der Waals forces in the entrance valley of the Cl + HD reaction are shown here to play a decisive role in the reaction's dynamics. Exact quantum mechanical calculations of reactive scattering on a potential energy surface without Cl-HD van der Waals forces predict that the HCl and DCl products will be produced almost equally, whereas the same calculations on a new ab initio potential energy surface with van der Waals forces show a strong preference for the production of DCl. This preference is also seen in crossed molecular beam experiments on the reaction. The study of chemical reaction dynamics has now advanced to the stage where even comparatively weak van der Waals interactions can no longer be neglected in calculations of the potential energy surfaces of chemical reactions.
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Affiliation(s)
- D Skouteris
- Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK. Institute fur Theoretische Chemie, Universitat Stuttgart, Pfaffenwaldring 55, D-75069 Stuttgart, Germany. Institute of Atomic and Molecular Sciences, Academia Sin
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