Universität zu Köln

Mishra, Piyush ORCID: 0000-0003-0916-1292, Fritz, Sean M., Herbers, Sven, Mebel, Alexander M. and Zwier, Timothy S. (2021). Gas-phase pyrolysis of trans 3-pentenenitrile: competition between direct and isomerization-mediated dissociation. Phys. Chem. Chem. Phys., 23 (11). S. 6462 - 6472. CAMBRIDGE: ROYAL SOC CHEMISTRY. ISSN 1463-9084

Full text not available from this repository.

Abstract

The flash pyrolysis of trans 3-pentenenitrile (3-PN, CH3-CH = CH-CH2-CN) was studied by combining the results of VUV photoionization mass spectra with broadband microwave spectra recorded as a function of the temperature of the pyrolysis tube. The two separated functional groups (vinyl and nitrile) open up isomerization as an initial step in competition with unimolecular dissociation. Primary products were detected by keeping the 3-PN concentration low and limiting reaction times to the traversal time of the gas in the pyrolysis tube (similar to 100 mu s). The reaction is quenched and products are cooled by expansion into vacuum before interrogation over the 8-18 GHz region using chirped-pulse broadband methods. 118 nm VUV photoionization of the same reaction mixture provides a means of detecting all products with ionization potentials below 10.5 eV with minimal fragmentation. These results are combined with a detailed computational investigation of the C5H7N and related potential energy surfaces, leading to a consistent picture of the unimolecular decomposition of 3-PN. Loss of two H-atoms to form a 79 amu product is proven from its microwave transitions to contain trans-Z-2,4-pentadienenitrile, while no pyridine is observed. Methyl loss, HCN loss, and breaking the central C(2)-C(3) bond all occur following isomerization of the position of the double bond, thereby opening up low-energy pathways to these decomposition channels.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Mishra, Piyush UNSPECIFIED orcid.org/0000-0003-0916-1292 UNSPECIFIED Fritz, Sean M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Herbers, Sven UNSPECIFIED UNSPECIFIED UNSPECIFIED Mebel, Alexander M. UNSPECIFIED UNSPECIFIED UNSPECIFIED Zwier, Timothy S. UNSPECIFIED UNSPECIFIED UNSPECIFIED
URN:	urn:nbn:de:hbz:38-597662
DOI:	10.1039/d1cp00104c
Journal or Publication Title:	Phys. Chem. Chem. Phys.
Volume:	23
Number:	11
Page Range:	S. 6462 - 6472
Date:	2021
Publisher:	ROYAL SOC CHEMISTRY
Place of Publication:	CAMBRIDGE
ISSN:	1463-9084
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language MICROWAVE SPECTROSCOPY; 1,3-BUTADIENE; BAND; INTERSTELLAR; MOLECULES; CHEMISTRY; MECHANISM; 2-BUTYNE; RADICALS; KINETICS Multiple languages Chemistry, Physical; Physics, Atomic, Molecular & Chemical Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/59766