A Triphenylamine with Two Phenoxy Radicals Having Unusual Bonding Patterns and a Closed‐Shell Electronic State

Abstract

Scheme 1. a) Structures of the galvinoxyl radical. Structures of 1 drawn as abiradical (b) and aclosed-shell form (c).

Modulation of Open‐shell Characters of Amine‐inserted Diphenoquinones via Structural Modification

“…[1][2][3] Recently,w e have reported structural and electronic properties of at riarylamine having two 2,6-di-tert-butylphenoxy radical on the central nitrogen atom (1). [4] Our study revealed that 1 had extended quinoids tructure resulting from the stronga ntiferromagnetic coupling between two phenoxy radicals through the central amino nitrogen atom. The two CÀNb onds between the central nitrogen atom and the phenoxy groups explicitly had multiple bond characterl eadingt oi ts closed-shell electronic nature in contrastt ot he other phenoxy radical-based diradicals.…”

“…[4] The obtained biphenols were oxidized with lead (IV) oxide in dichloromethane at room temperature. The biphenol precursors (3a-d)w ere obtained by the palladium-catalyzed Buchwald-Hartwig reaction between the corresponding aniline derivatives (Ar-NH 2 )a nd methoxymethyl (MOM)-protected 2,6-di-phenyl-4-bromophenol, followedb yt he deprotection of the MOM groups by acidification.…”

“…The biphenol precursors (3a-d)w ere obtained by the palladium-catalyzed Buchwald-Hartwig reaction between the corresponding aniline derivatives (Ar-NH 2 )a nd methoxymethyl (MOM)-protected 2,6-di-phenyl-4-bromophenol, followedb yt he deprotection of the MOM groups by acidification. [4] The obtained biphenols were oxidized with lead (IV) oxide in dichloromethane at room temperature. The reaction solutions exhibited deep blue-purple colors immediately after starting the reactions.…”

Persistent and Stable Organic Radicals: Design, Synthesis, and Applications

“…288-332,February 11, 2021 303 Review expected to distribute at the outer centers of the trimethylenemethane groups, whereas their charge orders were rather negligible according to the ESR and EN-DOR, as well as the quantum chemical calculations. Sakamaki et al75 reported a triphenylamine derivative 41 with two appended phenoxyl radicals. They experimentally determined that the molecule 41 possessed a closed-shell electronic structure and the C-N bonds had a multiple-bond character due to the robust delocalization.…”