Premium
Stable Nitrogen‐Centered Bis(imino)rylene Diradicaloids
Author(s) -
Zeng Wangdong,
Hong Yongseok,
Medina Rivero Samara,
Kim Jinseok,
Zafra José L.,
Phan Hoa,
Gopalakrishna Tullimilli Y.,
Herng Tun Seng,
Ding Jun,
Casado Juan,
Kim Dongho,
Wu Jishan
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201706041
Subject(s) - diradical , singlet state , photochemistry , chemistry , open shell , delocalized electron , radical , excited state , absorption (acoustics) , nitrogen , singlet fission , ground state , paramagnetism , materials science , atomic physics , organic chemistry , physics , quantum mechanics , composite material
The synthesis of stable open‐shell singlet diradicaloids is critical for their practical material application. So far, most reported examples are based on carbon‐centered radicals, which are intrinsically reactive, and there are very few examples of stable nitrogen‐centered diradicaloids. In this full paper, a series of soluble and stable bis(imino)rylenes up to octarylene were synthesized on the basis of newly developed dibromorylene intermediates. It was found that from hexarylene onward, these quinoidal rylenes showed open‐shell singlet ground states and could be thermally populated to paramagnetic triplet aminyl diradicals. They are stable due to efficient spin delocalization onto the rylene backbone as well as kinetic blocking of the aminyl sites by the bulky and electron‐deficient 2,4,6‐trichlorophenyl groups. They exhibited very different electronic structures, diradical character, excited‐state dynamics, one‐photon absorption, two‐photon absorption, and electrochemical properties from their respective aromatic rylene counterparts. These bis(imino)rylenes represent a rare class of stable, neutral, nitrogen‐centered aminyl diradicaloids.