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Acetylene and trans ‐Ethylene Bridged B III ‐Subporphyrin Dimers
Author(s) -
Bekki Yosuke,
Kang Seongsoo,
Kim Dongho,
Osuka Atsuhiro
Publication year - 2019
Publication title -
chemistry – an asian journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.18
H-Index - 106
eISSN - 1861-471X
pISSN - 1861-4728
DOI - 10.1002/asia.201900547
Subject(s) - acetylene , ethylene , chemistry , medicinal chemistry , stereochemistry , organic chemistry , catalysis
Acetylene and trans ‐ethylene bridged B III ‐subporphyrin dimers were synthesized by cross‐coupling reactions of meso ‐bromo B III subporphyrin. These dimers display perturbed and red‐shifted absorption spectra reaching around 750 nm and fluorescence reaching at around 850 nm with high quantum yields of 0.39 and 0.47, respectively. DFT calculations have revealed that the HOMOs and the LUMOs of both dimers are spread over the two subporphyrin units as an indication of effective conjugation between the two subporphyrin units. The large Stokes shifts and characteristic pico‐second time‐resolved transient absorption spectra indicated that the S 1 ‐states of the dimers relax with structural changes, which are larger for the trans ‐ethylene bridged dimer.