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Pantaleone S, Corno M, Rimola A, Balucani N, Ugliengo P. Computational Study on the Water Corrosion Process at Schreibersite (Fe 2NiP) Surfaces: from Phosphide to Phosphates. ACS EARTH & SPACE CHEMISTRY 2023; 7:2050-2061. [PMID: 37876665 PMCID: PMC10591503 DOI: 10.1021/acsearthspacechem.3c00167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/07/2023] [Accepted: 09/07/2023] [Indexed: 10/26/2023]
Abstract
Phosphorus (P) is a fundamental element for whatever form of life, in the same way as the other biogenic macroelements (SONCH). The prebiotic origin of P is still a matter of debate, as the phosphates present on earth are trapped in almost insoluble solid matrixes (apatites) and, therefore, hardly available for inclusion in living systems in the prebiotic era. The most accepted theories regard a possible exogenous origin during the Archean Era, through the meteoritic bombardment, when tons of reactive P in the form of phosphide ((Fe,Ni)3P, schreibersite mineral) reached the primordial earth, reacting with water and providing oxygenated phosphorus compounds (including phosphates). In the last 20 years, laboratory experiments demonstrated that the corrosion process of schreibersite by water indeed leads to reactive phosphates that, in turn, react with other biological building blocks (nucleosides and simple sugars) to form more complex molecules (nucleotides and complex sugars). In the present paper, we study the water corrosion of different crystalline surfaces of schreibersite by means of periodic DFT (density functional theory) simulations. Our results show that water adsorbs molecularly on the most stable (110) surface but dissociates on the less stable (001) one, giving rise to further reactivity. Indeed, subsequent water adsorptions, up to the water monolayer coverage, show that, on the (001) surface, iron and nickel atoms are the first species undergoing the corrosion process and, in a second stage, the phosphorus atoms also get involved. When adsorbing up to three and four water molecules per unit cell, the most stable structures found are the phosphite and phosphate forms of phosphorus, respectively. Simulation of the vibrational spectra of the considered reaction products revealed that the experimental band at 2423 cm-1 attributed to the P-H stretching frequency is indeed predicted for a phosphite moiety attached to the schreibersite (001) surface upon chemisorption of up to three water molecules.
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Balucani N, Bertin M, Brann M, Brown WA, Ceccarelli C, Martín-Doménech R, Fulker J, Garrod RT, Green J, Gudipati MS, Heard DE, Herbst E, Jacovella U, Kamp I, McCoustra MRS, Sameera WMC, Sims I, Sturm A, Viti S, Weaver SW, Wiesenfeld L, Wilkins OH. Laboratory astrochemistry of and on dust and ices: general discussion. Faraday Discuss 2023; 245:519-540. [PMID: 37665057 DOI: 10.1039/d3fd90026f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
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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] [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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Balucani N, Brann M, Brünken S, Ceccarelli C, Cordiner M, Crump EM, Douglas KM, Fleisher AJ, Flint A, Fulker J, Garrod RT, Gudipati MS, Gupta D, Halpern J, Heard DE, Herbst E, Hockey EK, Huang KY, Jacovella U, Kamp I, Lemmens AK, Madhusudhan N, McCoustra MRS, McGuire B, Meijer A, Puzzarini C, Rap DB, Sims IR, Stockett MH, Sturm A, Suits AG, van Dishoeck EF, Viti S, Walker N, Widicus Weaver S, Wiesenfeld L, Wilkins OH. Laboratory astrochemistry of the gas phase: general discussion. Faraday Discuss 2023; 245:391-445. [PMID: 37671500 DOI: 10.1039/d3fd90025h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/07/2023]
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Pannacci G, Mancini L, Vanuzzo G, Liang P, Marchione D, Rosi M, Casavecchia P, Balucani N. A combined crossed molecular beam and theorerical study of the O( 3P, 1D) + acrylonitrile (CH 2CHCN) reactions and implications for combustion and extraterrestrial environments. Phys Chem Chem Phys 2023. [PMID: 37469256 DOI: 10.1039/d3cp01558k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Acrylonitrile (CH2CHCN) is ubiquitous in space (molecular clouds, solar-type star forming regions, and circumstellar envelopes) and is also abundant in the upper atmosphere of Titan. The reaction O(3P) + CH2CHCN can be of relevance in the chemistry of the interstellar medium because of the abundance of atomic oxygen. The oxidation of acrylonitrile is also important in combustion as the thermal decomposition of pyrrolic and pyridinic structures present in fuel-bound nitrogen generates many nitrogen-bearing compounds, including acrylonitrile. Despite its relevance, limited information exists on this reaction. We report a combined experimental and theoretical investigation of the reactions of acrylonitrile with both ground 3P and excited 1D atomic oxygen. From product angular and time-of-flight distributions in crossed molecular beam experiments with mass spectrometric detection at a collision energy, Ec, of 31.4 kJ mol-1, we have identified the primary reaction products and determined their branching fractions (BFs). Theoretical calculations of the relevant triplet and singlet potential energy surfaces (PESs) were performed to interpret the experimental results and elucidate the reaction mechanism. Adiabatic statistical calculations of product BFs for the decomposition of the main triplet and singlet intermediates have been carried out. Combining the experimental and theoretical results, we conclude that the O(3P) reaction leads to two main product channels: (i) CH2CNH (ketenimine) + CO (dominant with a BF of 0.87 ± 0.05), formed via efficient intersystem crossing from the entrance triplet PES to the underlying singlet PES, and (ii) HCOCHCN + H (minor, with a BF of 0.13 ± 0.05), occurring adiabatically on the triplet PES. Our study suggests the inclusion of this reaction as a possible destruction pathway of CH2CHCN and a possible formation route of CH2CNH in the interstellar medium. The O(1D) + CH2CHCN reaction mainly leads to the formation of CH2CNH + CO adiabatically on the singlet PES. This result can improve models related to the chemistry of interstellar ice and cometary comas, where O(1D) reactions can play a role. Overall, our results are expected to be useful for improving the models of combustion and extraterrestrial environments.
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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] [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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Liang P, de Aragão EVF, Pannacci G, Vanuzzo G, Giustini A, Marchione D, Recio P, Ferlin F, Stranges D, Lago NF, Rosi M, Casavecchia P, Balucani N. Reactions O( 3P, 1D) + HCCCN(X 1Σ +) (Cyanoacetylene): Crossed-Beam and Theoretical Studies and Implications for the Chemistry of Extraterrestrial Environments. J Phys Chem A 2023; 127:685-703. [PMID: 36638186 PMCID: PMC9884085 DOI: 10.1021/acs.jpca.2c07708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Cyanoacetylene (HCCCN), the first member of the cyanopolyyne family (HCnN, where n = 3, 5, 7, ...), is of particular interest in astrochemistry being ubiquitous in space (molecular clouds, solar-type protostars, protoplanetary disks, circumstellar envelopes, and external galaxies) and also relatively abundant. It is also abundant in the upper atmosphere of Titan and comets. Since oxygen is the third most abundant element in space, after hydrogen and helium, the reaction O + HCCCN can be of relevance in the chemistry of extraterrestrial environments. Despite that, scarce information exists not only on the reactions of oxygen atoms with cyanoacetylene but with nitriles in general. Here, we report on a combined experimental and theoretical investigation of the reactions of cyanoacetylene with both ground 3P and excited 1D atomic oxygen and provide detailed information on the primary reaction products, their branching fractions (BFs), and the overall reaction mechanisms. More specifically, the reactions of O(3P, 1D) with HCCCN(X1Σ+) have been investigated under single-collision conditions by the crossed molecular beams scattering method with mass spectrometric detection and time-of-flight analysis at the collision energy, Ec, of 31.1 kJ/mol. From product angular and time-of-flight distributions, we have identified the primary reaction products and determined their branching fractions (BFs). Theoretical calculations of the relevant triplet and singlet potential energy surfaces (PESs) were performed to assist the interpretation of the experimental results and clarify the reaction mechanism. Adiabatic statistical calculations of product BFs for the decomposition of the main triplet and singlet intermediates have also been carried out. Merging together the experimental and theoretical results, we conclude that the O(3P) reaction is characterized by a minor adiabatic channel leading to OCCCN (cyanoketyl) + H (experimental BF = 0.10 ± 0.05), while the dominant channel (BF = 0.90 ± 0.05) occurs via intersystem crossing to the underlying singlet PES and leads to formation of 1HCCN (cyanomethylene) + CO. The O(1D) reaction is characterized by the same two channels, with the relative CO/H yield being slightly larger. Considering the recorded reactive signal and the calculated entrance barrier, we estimate that the rate coefficient for reaction O(3P) + HC3N at 300 K is in the 10-12 cm3 molec-1 s-1 range. Our results are expected to be useful to improve astrochemical and photochemical models. In addition, they are also relevant in combustion chemistry, because the thermal decomposition of pyrrolic and pyridinic structures present in fuel-bound nitrogen generates many nitrogen-bearing compounds, including cyanoacetylene.
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Recio P, Alessandrini S, Vanuzzo G, Pannacci G, Baggioli A, Marchione D, Caracciolo A, Murray VJ, Casavecchia P, Balucani N, Cavallotti C, Puzzarini C, Barone V. Intersystem crossing in the entrance channel of the reaction of O( 3P) with pyridine. Nat Chem 2022; 14:1405-1412. [PMID: 36175514 DOI: 10.1038/s41557-022-01047-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 08/25/2022] [Indexed: 01/04/2023]
Abstract
Two quantum effects can enable reactions to take place at energies below the barrier separating reactants from products: tunnelling and intersystem crossing between coupled potential energy surfaces. Here we show that intersystem crossing in the region between the pre-reactive complex and the reaction barrier can control the rate of bimolecular reactions for weakly coupled potential energy surfaces, even in the absence of heavy atoms. For O(3P) plus pyridine, a reaction relevant to combustion, astrochemistry and biochemistry, crossed-beam experiments indicate that the dominant products are pyrrole and CO, obtained through a spin-forbidden ring-contraction mechanism. The experimental findings are interpreted-by high-level quantum-chemical calculations and statistical non-adiabatic computations of branching fractions-in terms of an efficient intersystem crossing occurring before the high entrance barrier for O-atom addition to the N-atom lone pair. At low to moderate temperatures, the computed reaction rates prove to be dominated by intersystem crossing.
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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 CHEMISTRY 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] [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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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] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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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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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] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
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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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Perrero J, Enrique-Romero J, Martínez-Bachs B, Ceccarelli C, Balucani N, Ugliengo P, Rimola A. Non-energetic Formation of Ethanol via CCH Reaction with Interstellar H 2O Ices. A Computational Chemistry Study. ACS EARTH & SPACE CHEMISTRY 2022; 6:496-511. [PMID: 35330630 PMCID: PMC8935465 DOI: 10.1021/acsearthspacechem.1c00369] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Revised: 02/21/2022] [Accepted: 02/27/2022] [Indexed: 05/30/2023]
Abstract
Ethanol (CH3CH2OH) is a relatively common molecule, often found in star-forming regions. Recent studies suggest that it could be a parent molecule of several so-called interstellar complex organic molecules (iCOMs). However, the formation route of this species remains under debate. In the present work, we study the formation of ethanol through the reaction of CCH with one H2O molecule belonging to the ice as a test case to investigate the viability of chemical reactions based on a "radical + ice component" scheme as an alternative mechanism for the synthesis of iCOMs, beyond the usual radical-radical coupling. This has been done by means of DFT calculations adopting two clusters of 18 and 33 water molecules as ice models. Results indicate that CH3CH2OH can potentially be formed by this proposed reaction mechanism. The reaction of CCH with H2O on the water ice clusters can be barrierless (because of the help of boundary icy water molecules acting as proton-transfer assistants), leading to the formation of vinyl alcohol precursors (H2CCOH and CHCHOH). Subsequent hydrogenation of vinyl alcohol yielding ethanol is the only step presenting a low activation energy barrier. We finally discuss the astrophysical implications of these findings.
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Pantaleone S, Corno M, Rimola A, Balucani N, Ugliengo P. Water Interaction with Fe 2NiP Schreibersite (110) Surface: a Quantum Mechanical Atomistic Perspective. THE JOURNAL OF PHYSICAL CHEMISTRY. C, NANOMATERIALS AND INTERFACES 2022; 126:2243-2252. [PMID: 35145576 PMCID: PMC8819687 DOI: 10.1021/acs.jpcc.1c09947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 01/06/2022] [Indexed: 06/14/2023]
Abstract
Phosphorus is an element of primary importance for all living creatures, being present in many biological activities in the form of phosphate (PO4 3-). However, there are still open questions about the origin of this specific element and on the transformation that allowed it to be incorporated in biological systems. The most probable source of prebiotic phosphorus is the intense meteoritic bombardment during the Archean era, a few million years after the solar system formation, which brought tons of iron-phosphide materials (schreibersite) on the early Earth crust. It was recently demonstrated that by simple wetting/corrosion processes from this material, various oxygenated phosphorus compounds are produced. In the present work, the wetting process of schreibersite (Fe2NiP) was studied by computer simulations using density functional theory, with the PBE functional supplemented with dispersive interactions through a posteriori empirical correction. To start disentangling the complexity of the system, only the most stable (110) surface of Fe2NiP was used simulating different water coverages, from which structures, water binding energies, and vibrational spectra have been predicted. The computed (ana-)harmonic infrared spectra have been compared with the experimental ones, thus, confirming the validity of the adopted methodology and models.
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Cavallotti C, Della Libera A, Zhou CW, Recio P, Caracciolo A, Balucani N, Casavecchia P. Crossed-beam and theoretical studies of multichannel nonadiabatic reactions: branching fractions and role of intersystem crossing for O(3P)+1,3-butadiene. Faraday Discuss 2022; 238:161-182. [DOI: 10.1039/d2fd00037g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Atomic oxygen reactions can contribute significantly to the oxidation of unsaturated aliphatic and aromatic hydrocarbons. The reaction mechanism is started by electrophilic O atom addition to the unsaturated bond(s) to...
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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] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
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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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Vanuzzo G, Caracciolo A, Minton TK, Balucani N, Casavecchia P, de Falco C, Baggioli A, Cavallotti C. Crossed-Beam and Theoretical Studies of the O( 3P, 1D) + Benzene Reactions: Primary Products, Branching Fractions, and Role of Intersystem Crossing. J Phys Chem A 2021; 125:8434-8453. [PMID: 34533308 PMCID: PMC8488941 DOI: 10.1021/acs.jpca.1c06913] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Reliable modeling
of hydrocarbon oxidation relies critically on
knowledge of the branching fractions (BFs) as a function of temperature
(T) and pressure (p) for the products
of the reaction of the hydrocarbon with atomic oxygen in its ground
state, O(3P). During the past decade, we have performed
in-depth investigations of the reactions of O(3P) with
a variety of small unsaturated hydrocarbons using the crossed molecular
beam (CMB) technique with universal mass spectrometric
(MS) detection and time-of-flight (TOF) analysis, combined with synergistic
theoretical calculations of the relevant potential energy surfaces
(PESs) and statistical computations of product BFs, including intersystem
crossing (ISC). This has allowed us to determine the primary products,
their BFs, and extent of ISC to ultimately provide theoretical channel-specific
rate constants as a function of T and p. In this work, we have extended this approach to the oxidation of
one of the most important species involved in the combustion of aromatics:
the benzene (C6H6) molecule. Despite extensive
experimental and theoretical studies on the kinetics and dynamics
of the O(3P) + C6H6 reaction, the
relative importance of the C6H5O (phenoxy) +
H open-shell products and of the spin-forbidden C5H6 (cyclopentadiene) + CO and phenol adduct closed-shell products
are still open issues, which have hampered the development of reliable
benzene combustion models. With the CMB technique, we have investigated
the reaction dynamics of O(3P) + benzene at a collision
energy (Ec) of 8.2 kcal/mol, focusing
on the occurrence of the phenoxy + H and spin-forbidden C5H6 + CO and phenol channels in order to shed further light
on the dynamics of this complex and important reaction, including
the role of ISC. Concurrently, we have also investigated the reaction
dynamics of O(1D) + benzene at the same Ec. Synergistic high-level electronic structure calculations
of the underlying triplet/singlet PESs, including nonadiabatic couplings,
have been performed to complement and assist the interpretation of
the experimental results. Statistical (RRKM)/master equation (ME)
computations of the product distribution and BFs on these PESs, with
inclusion of ISC, have been performed and compared to experiment.
In light of the reasonable agreement between the CMB experiment, literature
kinetic experimental results, and theoretical predictions for the
O(3P) + benzene reaction, the so-validated computational
methodology has been used to predict (i) the BF between the C6H5O + H and C5H6 + CO channels
as a function of collision energy and temperature (at 0.1 and 1 bar),
showing that their increase progressively favors radical (phenoxy
+ H)-forming over molecule (C5H6 + CO and phenol
stabilization)-forming channels, and (ii) channel-specific rate constants
as a function of T and p, which
are expected to be useful for improved combustion models.
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Recio P, Marchione D, Caracciolo A, Murray VJ, Mancini L, Rosi M, Casavecchia P, Balucani N. A crossed molecular beam investigation of the N(2D) + pyridine reaction and implications for prebiotic chemistry. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Liang P, Mancini L, Marchione D, Vanuzzo G, Ferlin F, Recio P, Tan Y, Pannacci G, Vaccaro L, Rosi M, Casavecchia P, Balucani N. Combined crossed molecular beams and computational study on the N( 2D) + HCCCN(X 1Σ +) reaction and implications for extra-terrestrial environments. Mol Phys 2021. [DOI: 10.1080/00268976.2021.1948126] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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19
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Cavallotti C, De Falco C, Pratali Maffei L, Caracciolo A, Vanuzzo G, Balucani N, Casavecchia P. Theoretical Study of the Extent of Intersystem Crossing in the O( 3P) + C 6H 6 Reaction with Experimental Validation. J Phys Chem Lett 2020; 11:9621-9628. [PMID: 33125250 PMCID: PMC8016199 DOI: 10.1021/acs.jpclett.0c02866] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2020] [Accepted: 10/22/2020] [Indexed: 05/30/2023]
Abstract
The extent of intersystem crossing in the O(3P) + C6H6 reaction, a prototypical system for spin-forbidden reactions in oxygenated aromatic molecules, is theoretically evaluated for the first time. Calculations are performed using nonadiabatic transition-state theory coupled with stochastic master equation simulations and Landau-Zener theory. It is found that the dominant intersystem crossing pathways connect the T2 and S0 potential energy surfaces through at least two distinct minimum-energy crossing points. The calculated channel-specific rate constants and intersystem crossing branching fractions differ from previous literature estimates and provide valuable kinetic data for the investigation of benzene and polycyclic aromatic hydrocarbons oxidation in interstellar, atmospheric, and combustion conditions. The theoretical results are supported by crossed molecular beam experiments with electron ionization mass-spectrometric detection and time-of-flight analysis at 8.2 kcal/mol collision energy. This system is a suitable benchmark for theoretical and experimental studies of intersystem crossing in aromatic species.
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Signorile M, Pantaleone S, Balucani N, Bonino F, Martra G, Ugliengo P. Monitoring the Reactivity of Formamide on Amorphous SiO 2 by In-Situ UV-Raman Spectroscopy and DFT Modeling. Molecules 2020; 25:molecules25102274. [PMID: 32408593 PMCID: PMC7287731 DOI: 10.3390/molecules25102274] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Revised: 05/08/2020] [Accepted: 05/09/2020] [Indexed: 01/10/2023] Open
Abstract
Formamide has been recognized in the literature as a key species in the formation of the complex molecules of life, such as nucleobases. Furthermore, several studies reported the impact of mineral phases as catalysts for its decomposition/polymerization processes, increasing the conversion and also favoring the formation of specific products. Despite the progresses in the field, in situ studies on these mineral-catalyzed processes are missing. In this work, we present an in situ UV-Raman characterization of the chemical evolution of formamide over amorphous SiO2 samples, selected as a prototype of silicate minerals. The experiments were carried out after reaction of formamide at 160 °C on amorphous SiO2 (Aerosil OX50) either pristine or pre-calcined at 450 °C, to remove a large fraction of surface silanol groups. Our measurements, interpreted on the basis of density functional B3LYP-D3 calculations, allow to assign the spectra bands in terms of specific complex organic molecules, namely, diaminomaleonitrile (DAMN), 5-aminoimidazole (AI), and purine, showing the role of the mineral surface on the formation of relevant prebiotic molecules.
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21
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Onofri S, Balucani N, Barone V, Benedetti P, Billi D, Balbi A, Brucato JR, Cobucci-Ponzano B, Costanzo G, Rocca NL, Moracci M, Saladino R, Vladilo G. The Italian National Project of Astrobiology-Life in Space-Origin, Presence, Persistence of Life in Space, from Molecules to Extremophiles. ASTROBIOLOGY 2020; 20:580-582. [PMID: 32364794 PMCID: PMC7232638 DOI: 10.1089/ast.2020.2247] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Accepted: 02/18/2020] [Indexed: 06/11/2023]
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22
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Caracciolo A, Vanuzzo G, Balucani N, Stranges D, Casavecchia P, Pratali Maffei L, Cavallotti C. Combined Experimental and Theoretical Studies of the O(3P) + 1-Butene Reaction Dynamics: Primary Products, Branching Fractions, and Role of Intersystem Crossing. J Phys Chem A 2019; 123:9934-9956. [DOI: 10.1021/acs.jpca.9b07621] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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23
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Falcinelli S, Rosi M, Pirani F, Bassi D, Alagia M, Schio L, Richter R, Stranges S, Balucani N, Lorent V, Vecchiocattivi F. Angular Distribution of Ion Products in the Double Photoionization of Propylene Oxide. Front Chem 2019; 7:621. [PMID: 31572712 PMCID: PMC6749015 DOI: 10.3389/fchem.2019.00621] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 08/29/2019] [Indexed: 11/13/2022] Open
Abstract
A photoelectron-photoion-photoion coincidence technique, using an ion imaging detector and tunable synchrotron radiation in the 18.0–37.0 eV photon energy range, inducing the ejection of molecular valence electrons, has been applied to study the double ionization of the propylene oxide, a simple prototype chiral molecule. The experiment performed at the Elettra Synchrotron Facility (Trieste, Italy) allowed to determine angular distributions for ions produced by the two-body dissociation reactions following the Coulomb explosion of the intermediate (C3H6O)2+ molecular dication. The analysis of the coincidence spectra recorded at different photon energies was done in order to determine the dependence of the β anisotropy parameter on the photon energy for the investigated two-body fragmentation channels. In particular, the reaction leading to CH3+ + C2H3O+ appears to be characterized by an increase of β, from β ≈ 0.00 up to β = 0.59, as the photon energy increases from 29.7 to 37.0 eV, respectively. This new observation confirms that the dissociation channel producing CH3+ and C2H3O+ final ions can occur with two different microscopic mechanisms as already indicated by the bimodality obtained in the kinetic energy released (KER) distributions as a function of the photon energy in a recent study. Energetic considerations suggest that experimental data are compatible with the formation of two different stable isomers of C2H3O+: acetyl and oxiranyl cations. These new experimental data are inherently relevant and are mandatory information for further experimental and theoretical investigations involving oriented chiral molecules and linearly or circularly polarized radiation. This work is in progress in our laboratory.
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Rosi M, Skouteris D, Balucani N, Nappi C, Faginas Lago N, Pacifici L, Falcinelli S, Stranges D. An Experimental and Theoretical Investigation of 1-Butanol Pyrolysis. Front Chem 2019; 7:326. [PMID: 31139618 PMCID: PMC6527765 DOI: 10.3389/fchem.2019.00326] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/23/2019] [Indexed: 11/17/2022] Open
Abstract
Bioalcohols are a promising family of biofuels. Among them, 1-butanol has a strong potential as a substitute for petrol. In this manuscript, we report on a theoretical and experimental characterization of 1-butanol thermal decomposition, a very important process in the 1-butanol combustion at high temperatures. Advantage has been taken of a flash pyrolysis experimental set-up with mass spectrometric detection, in which the brief residence time of the pyrolyzing mixture inside a short, resistively heated SiC tube allows the identification of the primary products of the decomposing species, limiting secondary processes. Dedicated electronic structure calculations of the relevant potential energy surface have also been performed and RRKM estimates of the rate coefficients and product branching ratios up to 2,000 K are provided. Both electronic structure and RRKM calculations are in line with previous determinations. According to the present study, the H2O elimination channel leading to 1-butene is more important than previously believed. In addition to that, we provide experimental evidence that butanal formation by H2 elimination is not a primary decomposition route. Finally, we have experimental evidence of a small yield of the CH3 elimination channel.
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Balucani N. An atomistic approach to prebiotic chemistry: A tool to overcome the limits of laboratory simulations: Comment on "Prebiotic chemistry and origins of life research with atomistic computer simulations". Phys Life Rev 2019; 34-35:136-138. [PMID: 30905552 DOI: 10.1016/j.plrev.2019.03.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 03/13/2019] [Indexed: 11/26/2022]
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