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Sequential N ‐Alkylations of Tetrabenzotetraaza[8]circulene as a Tool To Tune Its Optical Properties
Author(s) -
Chen Fengkun,
Hong Yong Seok,
Kim Dongho,
Tanaka Takayuki,
Osuka Atsuhiro
Publication year - 2017
Publication title -
chempluschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.801
H-Index - 61
ISSN - 2192-6506
DOI - 10.1002/cplu.201600537
Subject(s) - planarity testing , steric effects , alkylation , chemistry , alkyl , tetra , excited state , nitrogen , photochemistry , stereochemistry , medicinal chemistry , crystallography , organic chemistry , catalysis , physics , nuclear physics
Sequential N ‐alkylations of tetrabenzotetraaza[8]circulene provided mono‐, di‐, tri, and tetra‐ N ‐alkylated products in a controlled manner. Curiously, only opp isomer was obtained as a di‐ N ‐alkylated product. Upon increase of the N ‐alkyl groups, the absorption and emission spectra exhibit continuous red‐shifts, and the excited‐state lifetimes become shortened, probably because of increased steric congestion at the nitrogen atoms that causes the central core to deviate from planarity. Mixed N ‐substituted [8]circulenes have been also prepared.