A Caltech Library Service

Rate Constants of the CN + Toluene Reaction from 15 – 294 K and Interstellar Implications

Messinger, Joseph P. and Gupta, Divita and Cooke, Ilsa R. and Okumura, Mitchio and Sims, Ian R. (2020) Rate Constants of the CN + Toluene Reaction from 15 – 294 K and Interstellar Implications. Journal of Physical Chemistry A, 124 (39). pp. 7950-7958. ISSN 1089-5639.

[img] PDF - Accepted Version
See Usage Policy.

[img] PDF (Geometries of calculated structures for all molecules and transition states) - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


CN is known for its fast reactions with hydrocarbons at low temperatures, but relatively few studies have focused on the reactions between CN and aromatic molecules. The recent detection of benzonitrile in the interstellar medium, believed to be produced by the reaction of CN and benzene, has ignited interest in studying these reactions. Here, we report rate constants of the CN + toluene (C₇H₈) reaction between 15 and 294 K using a CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme; reaction kinetics in uniform supersonic flow) apparatus coupled with the pulsed laser photolysis–laser-induced fluorescence (PLP–LIF) technique. We also present the stationary points on the potential energy surface of this reaction to study the available reaction pathways. We find the rate constant does not change over this temperature range, with an average value of (4.1 ± 0.2) × 10⁻¹⁰ cm³ s⁻¹, which is notably faster than the only previous measurement at 105 K. While the reason for this disagreement is unknown, we discuss the possibility that it is related to enhanced multiphoton effects in the previous work.

Item Type:Article
Related URLs:
URLURL TypeDescription
Messinger, Joseph P.0000-0001-7305-3945
Gupta, Divita0000-0002-6639-4909
Cooke, Ilsa R.0000-0002-0850-7426
Okumura, Mitchio0000-0001-6874-1137
Sims, Ian R.0000-0001-7870-1585
Additional Information:© 2020 American Chemical Society. Received: July 28, 2020; Revised: August 31, 2020; Published: September 2, 2020. The authors thank Jonathan Courbe, Jonathan Thiévin, Didier Biet, Ewen Gallou, and Alexandre Dapp for technical support. We would like to acknowledge Mayank Saraswat for helpful discussions regarding the PES calculations. J.P.M. was supported by the National Science Foundation Graduate Research Fellowship (NSF GRP) and the National Science Foundation Graduate Research Opportunities Worldwide (NSF GROW) programs. J.P.M. would also like to thank the Office of Science and Technology of the Embassy of France in the United States for a Chateaubriand Fellowship. The authors acknowledge funding from the European Union’s Horizon 2020 research and innovation programme under the European Research Council (ERC) grant agreement 695724-CRESUCHIRP and under the Marie Skłodowska-Curie grant agreement 845165-MIRAGE. Acknowledgment is made to the donors of The American Chemical Society Petroleum Research Fund for partial support of this research. The authors are also grateful for support from the European Regional Development Fund, the Region of Brittany, and Rennes Metropole. This work was supported by the French National Programme “Physique et Chimie du Milieu Interstellaire” (PCMI) of CNRS/INSU with INC/INP cofunded by CEA and CNES. The authors declare no competing financial interest.
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Office of Science and Technology of the Embassy of FranceUNSPECIFIED
European Research Council (ERC)695724-CRESUCHIRP
Marie Curie Fellowship845165-MIRAGE
American Chemical Society Petroleum Research FundUNSPECIFIED
European Regional Development FundUNSPECIFIED
Region of Brittany and Rennes MetropoleUNSPECIFIED
Centre National de la Recherche Scientifique (CNRS)UNSPECIFIED
Institut National des Sciences de l'Univers (INSU)UNSPECIFIED
Commissariat à l'énergie atomique (CEA)UNSPECIFIED
Centre National d'Études Spatiales (CNES)UNSPECIFIED
Issue or Number:39
Record Number:CaltechAUTHORS:20200903-150859694
Persistent URL:
Official Citation:Rate Constants of the CN + Toluene Reaction from 15 to 294 K and Interstellar Implications. Joseph P. Messinger, Divita Gupta, Ilsa R. Cooke, Mitchio Okumura, and Ian R. Sims. The Journal of Physical Chemistry A 2020 124 (39), 7950-7958; DOI: 10.1021/acs.jpca.0c06900
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105252
Deposited By: Tony Diaz
Deposited On:08 Sep 2020 17:07
Last Modified:07 Oct 2020 17:55

Repository Staff Only: item control page