On the temperature dependence of the rate coefficient of formation of C$_2^+$ from C + CH<sup>+</sup>

Rampino, Sergio; Pastore, Mariachiara; Garcı́a, Ernesto; Pacifici, Leonardo; Laganá, Antonio

doi:10.1093/mnras/stw1116

Cited by 19 publications

(27 citation statements)

References 73 publications

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“…Elementary reactions, widely investigated both experimentally and theoretically, which have been described successfully, are F + H 2 [28,96], F + HD [113], CH 4 + OH [20], CH 3 Cl + OH [20], H 2 + CN [20], and also abstraction and dissociation in the nitrogen trifluoride channels [114], and proton rearrangement in curcumin [115] and methylhydroxycarbene [116]. The deformed formulation has also been found useful to describe other reactions not involving tunnelling but showing non-negligible sub-Arrhenius behaviour, such as the C + CH + reaction [117], which is of relevance in cold interstellar clouds.…”

Section: (I) Transition State Theorymentioning

confidence: 99%

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Aquilanti

Coutinho

Carvalho-Silva

2017

Phil. Trans. R. Soc. A.

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relaxing the thermodynamic equilibrium limit, either for a binomial distribution if d > 0 or for a negative binomial distribution if d < 0, formally corresponding to Fermionlike or Boson-like statistics, respectively. The current status of the phenomenology is illustrated emphasizing case studies; specifically (i) the super-Arrhenius kinetics, where transport phenomena accelerate processes as the temperature increases; (ii) the sub-Arrhenius kinetics, where quantum mechanical tunnelling propitiates low-temperature reactivity; (iii) the anti-Arrhenius kinetics, where processes with no energetic obstacles are rate-limited by molecular reorientation requirements. Particular attention is given for case (i) to the treatment of diffusion and viscosity, for case (ii) to formulation of a transition rate theory for chemical kinetics including quantum mechanical tunnelling, and for case (iii) to the stereodirectional specificity of the dynamics of reactions strongly hindered by the increase of temperature.This article is part of the themed issue 'Theoretical and computational studies of nonequilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.

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Section: (I) Transition State Theorymentioning

confidence: 99%

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Aquilanti

Coutinho

Carvalho-Silva

2017

Phil. Trans. R. Soc. A.

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“…A PES for the C 2 H + system has been published and described in References and . Here we briefly recall the methodology used to assemble it.…”

Section: Case Studiesmentioning

confidence: 99%

Chemical promenades: Exploring potential‐energy surfaces with immersive virtual reality

et al. 2020

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The virtual-reality framework AVATAR (Advanced Virtual Approach to Topological Analysis of Reactivity) for the immersive exploration of potential-energy landscapes is presented. AVATAR is based on modern consumer-grade virtual-reality technology and builds on two key concepts: (a) the reduction of the dimensionality of the potential-energy surface to two process-tailored, physically meaningful generalized coordinates, and (b) the analogy between the evolution of a chemical process and a pathway through valleys (potential wells) and mountain passes (saddle points) of the associated potential energy landscape. Examples including the discovery of competitive reaction paths in simple A + BC collisional systems and the interconversion between conformers in ring-puckering motions of flexible rings highlight the innovation potential that augmented and virtual reality convey for teaching, training, and supporting research in chemistry. K E Y W O R D S atom diatom reactions, immersive virtual reality, potential energy surface, ring puckering motions 1 | INTRODUCTION As well known, rigorous simulations of molecular processes should be based on the solution of the Schrödinger equation for the wavefunction of the involved nuclei and electrons, which is usually cast in its nonrelativistic time-independent form with a Hamiltonian including a kinetic term for the electronsT e , a kinetic term for the nucleiT N , and an interaction-potential term V (r, R), with r and R being the set of spatial coordinates of electrons and nuclei, respectively.This equation is seldom solved as is, due to the associated mathematical difficulties and computational cost. More commonly, on the grounds that the nuclei are much heavier than the electrons, the Born-Oppenheimer approximation [1] is adopted and the problem is broken down in two separate problems, one for the motion of the electrons at a given nuclear geometry:T

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“…A characterizing feature of the code is the consistent use of the d-formulation, which recently culminated in a series of successful applications from phenomenological to first-principles descriptions of pure and applied chemical kinetics and material science. Examples are available:From the phenomenology of elementary processes (such as the H 2 + F [94], OH + HBr [80], F + HD [65] and C + CH + [95] reactions) to complex processes (such as food systems [96], plant respiration [25], plasma chemistry [97], and solid-state diffusive reaction [98]);Calculation of the kinetic rate constants for chemical reactions from the potential energy surface features profile, such as the CH 4 + OH [60], CH 3 OH + H [99], OH + HCl [44], OH + HI [43], to proton rearrangement of enol forms of curcumin [100], OH + H 2 [101], and chiral nucleophilic substitution reaction [102]. …”

Section: Final Remarksmentioning

confidence: 99%

“…From the phenomenology of elementary processes (such as the H 2 + F [94], OH + HBr [80], F + HD [65] and C + CH + [95] reactions) to complex processes (such as food systems [96], plant respiration [25], plasma chemistry [97], and solid-state diffusive reaction [98]);…”

Section: Final Remarksmentioning

confidence: 99%

“Transitivity”: A Code for Computing Kinetic and Related Parameters in Chemical Transformations and Transport Phenomena

et al. 2019

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The Transitivity function, defined in terms of the reciprocal of the apparent activation energy, measures the propensity for a reaction to proceed and can provide a tool for implementing phenomenological kinetic models. Applications to systems which deviate from the Arrhenius law at low temperature encouraged the development of a user-friendly graphical interface for estimating the kinetic and thermodynamic parameters of physical and chemical processes. Here, we document the Transitivity code, written in Python, a free open-source code compatible with Windows, Linux and macOS platforms. Procedures are made available to evaluate the phenomenology of the temperature dependence of rate constants for processes from the Arrhenius and Transitivity plots. Reaction rate constants can be calculated by the traditional Transition-State Theory using a set of one-dimensional tunneling corrections (Bell (1935), Bell (1958), Skodje and Truhlar and, in particular, the deformed (d-TST) approach). To account for the solvent effect on reaction rate constant, implementation is given of the Kramers and of Collins–Kimball formulations. An input file generator is provided to run various molecular dynamics approaches in CPMD code. Examples are worked out and made available for testing. The novelty of this code is its general scope and particular exploit of d-formulations to cope with non-Arrhenius behavior at low temperatures, a topic which is the focus of recent intense investigations. We expect that this code serves as a quick and practical tool for data documentation from electronic structure calculations: It presents a very intuitive graphical interface which we believe to provide an excellent working tool for researchers and as courseware to teach statistical thermodynamics, thermochemistry, kinetics, and related areas.

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On the temperature dependence of the rate coefficient of formation of C$_2^+$ from C + CH⁺

Cited by 19 publications

References 73 publications

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Chemical promenades: Exploring potential‐energy surfaces with immersive virtual reality

“Transitivity”: A Code for Computing Kinetic and Related Parameters in Chemical Transformations and Transport Phenomena

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On the temperature dependence of the rate coefficient of formation of C$_2^+$ from C + CH+

Cited by 19 publications

References 73 publications

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Kinetics of low-temperature transitions and a reaction rate theory from non-equilibrium distributions

Chemical promenades: Exploring potential‐energy surfaces with immersive virtual reality

“Transitivity”: A Code for Computing Kinetic and Related Parameters in Chemical Transformations and Transport Phenomena

Contact Info

Product

Resources

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On the temperature dependence of the rate coefficient of formation of C$_2^+$ from C + CH⁺