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The dynamics of the C + PH3 reaction: a theoretical study
R Rey-Villaverde1, S Álvarez-Barcia, J R Flores
1Departamento de Química Física, Facultad de Química, Universidade de Vigo, E-36310-Vigo (Pontevedra), Spain.
The Journal of Chemical Physics
|July 12, 2012
Summary
The C + PH(3) reaction forms P-C bonds, crucial for astrochemistry. Theoretical studies reveal its high rate and temperature dependence, with HPCH + H as the primary product.
Area of Science:
- Astrochemistry
- Chemical Kinetics
- Theoretical Chemistry
Background:
- The reaction between carbon atoms (C) and phosphine (PH(3)) is a fundamental gas-phase process.
- It is significant for understanding the formation of phosphorus-containing molecules in interstellar environments.
- This reaction serves as a model for other phosphine reactions with carbon-based radicals.
Purpose of the Study:
- To investigate the dynamical aspects of the C + PH(3) reaction.
- To determine the reaction rate as a function of temperature.
- To elucidate the branching ratios and molecular mechanisms involved.
Main Methods:
- Utilized quasi-classical trajectory (QCT) methods for theoretical dynamical studies.
- Analyzed the capture rate and its dependence on temperature.
- Investigated the influence of the CPH(3) complex isomerization on the reaction rate.
Main Results:
- The capture rate exhibits a T(0.2) dependence.
- A high total rate of 0.82 × 10⁻¹⁰ cm³ s⁻¹ was obtained at 300 K.
- The reaction rate shows a weak dependence on temperature, despite high-lying saddle points in the CPH(3) complex.
Conclusions:
- The C + PH(3) reaction proceeds with a significant rate, higher than comparable neutral-neutral reactions.
- Several P-C bond-containing products are formed.
- The primary reaction channel leads to the formation of HPCH + H.
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