Premium
Unexpected Chemistry from the Reaction of Naphthyl and Acetylene at Combustion‐Like Temperatures
Author(s) -
Parker Dorian S. N.,
Kaiser Ralf. I.,
Bandyopadhyay Biswajit,
Kostko Oleg,
Troy Tyler P.,
Ahmed Musahid
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201411987
Subject(s) - acetylene , chemistry , anthracene , acenaphthylene , hydrogen atom abstraction , photochemistry , ring (chemistry) , radical , phenanthrene , reaction mechanism , computational chemistry , organic chemistry , catalysis
The hydrogen abstraction/acetylene addition (HACA) mechanism has long been viewed as a key route to aromatic ring growth of polycyclic aromatic hydrocarbons (PAHs) in combustion systems. However, doubt has been drawn on the ubiquity of the mechanism by recent electronic structure calculations which predict that the HACA mechanism starting from the naphthyl radical preferentially forms acenaphthylene, thereby blocking cyclization to a third six‐membered ring. Here, by probing the products formed in the reaction of 1‐ and 2‐naphthyl radicals in excess acetylene under combustion‐like conditions with the help of photoionization mass spectrometry, we provide experimental evidence that this reaction produces 1‐ and 2‐ethynylnaphthalenes (C 12 H 8 ), acenaphthylene (C 12 H 8 ) and diethynylnaphthalenes (C 14 H 8 ). Importantly, neither phenanthrene nor anthracene (C 14 H 10 ) was found, which indicates that the HACA mechanism does not lead to cyclization of the third aromatic ring as expected but rather undergoes ethynyl substitution reactions instead.