# Experimental and Theoretical Study of the Reaction of F2 with Thiirane

## TL;DR

This study experimentally and theoretically examines the reaction of fluorine gas with thiirane, measuring reaction rates and identifying products.

## Contribution

The first experimental and theoretical investigation of the F2 reaction with thiirane, including rate constants and product yields.

## Key findings

- The rate constant for the F2-thiirane reaction was determined as k1 = (5.79 ± 0.17) × 10−12 exp(−(16 ± 10)/T) cm3 molecule−1 s−1.
- HF and CH2CHSF were identified as primary products with HF yield at 100% across the temperature range.
- Quantum computations showed strongly exothermic reaction enthalpies ranging from −409.9 to −509.1 kJ mol−1.

## Abstract

The kinetics of the F2 reaction with thiirane (C2H4S) was studied for the first time in a flow reactor combined with mass spectrometry at a total helium pressure of 2 Torr and in the temperature range of 220 to 800 K. The rate constant of the title reaction was determined under pseudo-first-order conditions, either monitoring the kinetics of F2 or C2H4S consumption in excess of thiirane or of F2, respectively: k1 = (5.79 ± 0.17) × 10−12 exp(−(16 ± 10)/T) cm3 molecule−1 s−1 (the uncertainties represent precision of the fit at the 2σ level, with the total 2σ relative uncertainty, including statistical and systematic errors on the rate constant being 15% at all temperatures). HF and CH2CHSF were identified as primary products of the title reaction. The yield of HF was measured to be 100% (with an accuracy of 10%) across the entire temperature range of the study. Quantum computations revealed reaction enthalpies ranging from −409.9 to −509.1 kJ mol−1 for all the isomers/conformers of the products, indicating a strong exothermicity. Boltzmann relative populations were then established for different temperatures.