Premium
A Unified Mechanism on the Formation of Acenes, Helicenes, and Phenacenes in the Gas Phase
Author(s) -
Zhao Long,
Kaiser Ralf I.,
Xu Bo,
Ablikim Utuq,
Ahmed Musahid,
Evseev Mikhail M.,
Bashkirov Eugene K.,
Azyazov Valeriy N.,
Mebel Alexander M.
Publication year - 2020
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.201913037
Subject(s) - helicene , tetracene , chemistry , acene , gas phase , coronene , aromaticity , benzene , computational chemistry , phase (matter) , biphenyl , chemical physics , photochemistry , organic chemistry , molecule , anthracene
A unified low‐temperature reaction mechanism on the formation of acenes, phenacenes, and helicenes—polycyclic aromatic hydrocarbons (PAHs) that are distinct via the linear, zigzag, and ortho ‐condensed arrangements of fused benzene rings—is revealed. This mechanism is mediated through a barrierless, vinylacetylene mediated gas‐phase chemistry utilizing tetracene, [4]phenacene, and [4]helicene as benchmarks contesting established ideas that molecular mass growth processes to PAHs transpire at elevated temperatures. This mechanism opens up an isomer‐selective route to aromatic structures involving submerged reaction barriers, resonantly stabilized free‐radical intermediates, and systematic ring annulation potentially yielding molecular wires along with racemic mixtures of helicenes in deep space. Connecting helicene templates to the Origins of Life ultimately changes our hypothesis on interstellar carbon chemistry.