Takanori Suzuki

Electrochromic materials (EMs) are widely used color-switchable materials, but their applications as stimuli-responsive biomaterials to monitor and control biological processes remain unexplored. This study reports the engineering of an organic π-electron structure-based EM (dicationic 1,1,4,4-tetraarylbutadiene, 1²⁺) as a unique hydrogen sulfide (H₂S)-responsive chromophore amenable to build H₂S-activatable fluorescent probes (1²⁺-semiconducting polym

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTClathrate formation and molecular recognition by novel chalcogen-cyano interactions in tetracyanoquinodimethanes fused with thiadiazole and selenadiazole ringsTakanori Suzuki, Hiroshi Fujii, Yoshiro Yamashita, Chizuko Kabuto, Shoji Tanaka, Masako Harasawa, Toshio Mukai, and Tsutomu MiyashiCite this: J. Am. Chem. Soc. 1992, 114, 8, 3034–3043Publication Date (Print):April 1, 1992Publication History Published online1 May 2002Published inissue 1 April 1992

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAn Absolute Asymmetric Synthesis of the [2 + 2] Cycloadduct via Single Crystal-to-Single Crystal Transformation by Charge-Transfer Excitation of Solid-State Molecular Complexes Composed of Arylolefins and Bis[1,2,5]thiadiazolotetracyanoquinodimethaneTakanori Suzuki, Takanori Fukushima, Yoshiro Yamashita, and Tsutomu MiyashiCite this: J. Am. Chem. Soc. 1994, 116, 7, 2793–2803Publication Date (Print):April 1, 1994Publication History Published online1 May

Upon two-electron oxidation of the title electron donor 1a, the elongated central C9–C10 bond [1.656(5) Å (X-ray)] is cleaved to give the biphenyl-2,2′-diyl bis(xanthenylium) dye 2a2+, which regenerates the colorless dispiro compound 1a by two-electron reduction. The presence of isosbestic points in the UV–Vis spectra during the electrochemical oxidation of 1a to 2a2+ indicates the negligible steady-state concentration of the intermediate cation radical. Interconversion between optically resolve

Reversible CC bond breaking/making as well as drastic change in color are induced upon electron transfer in the novel redox couples of hexaarylethanes 1 and bis(triarylmethyl) dications 22+. Their hysteretic redox behaviors result from the quite different geometries of 1 and 22+. Ar = p-Me2NC6H4, p-MeOC6H4.

Sterically hindered C═C double bonds often deform into a bent or twisted geometry. Thus, many overcrowded ethylenes or anthraquinodimethanes can adopt multiple conformations, such as a folded form or a twisted form, which are interconvertible under the application of external stimuli. A perpendicular form with biradical character can also be adopted when designed to incorporate a stable carbon-based radical unit, which is involved in stimuli-responsive magnetic switching accompanied by a structu

'Dynamic redox systems' is the name given to a certain class of compounds that can be reversibly converted into the corresponding charged species accompanied by C-C bond formation/cleavage upon electron transfer. This account details the two major motifs (hexaphenylethane derivatives and butane-1,4-diyl dications) that have been developed in the principal author's group.

Accurate detection of hepatic hydrogen sulfide (H₂ S) to monitor H₂ S-related enzymes' activity is critical for acute hepatitis diagnosis, but remains a challenge due to the dynamic and transient nature of H₂ S. Here, we report a H₂ S-activatable near-infrared afterglow/MRI bimodal probe F1-GdNP, which shows an "always-on" MRI signal and "off-on" afterglow signal toward H₂ S. F1-GdNP shows fast response, high sensitivity and specificity towa

Hydrogen sulfide (H₂S) has shown promise for gas therapy. However, it is still controversial whether H₂S can remodel the tumor microenvironment (TME) and induce robust antitumor immunity. Here, a tumor-targeting and TME-responsive "smart" lipid nanoparticle (<b>1</b>-JK-PS-FA) is presented, which is capable of delivering and releasing H₂S specifically in tumor tissues for on-demand H₂S gas and photodynamic immunotherapy. <b>1</b>-JK-PS-FA enables a bur

4,7-Bis(dialkylamino)benzo[c][1,2,5]chalcogenadiazoles are a novel class of organic dyes that undergo reversible two-stage one-electron oxidation as well as one-electron reduction. They exhibit absorption maxima in the long-wavelength region, which are assigned as intramolecular charge transfer bands from the phenylenediamine moiety to the electron-accepting heterocycle. Their redox properties as well as molecular and crystal structures are affected by the alkyl substituents on the amino nitroge

Highly strained hydrocarbons with two di/tribenzocycloheptatriene units were designed as electrochromic overcrowded ethylenes that undergo reversible interconversion with stable dicationic dyes. Due to severe steric repulsion, two configurational isomers (<i>anti</i>,<i>anti</i>-folded and <i>syn</i>,<i>anti</i>-folded forms) were isolated as stable entities. Photo- and thermal interconversion of these isomers proceeded cleanly: one-way photoisomerization occurred from <i>anti</i>,<i>anti</i>- t

Thermally switchable redox properties have been reported to be due to a change in the spin state of newly designed overcrowded ethylenes, which can adopt closed-shell folded and open-shell twisted forms. In this study, tetrathienylanthraquinodimethane derivatives were designed to be in thermal equilibrium between a more stable folded form and less stable but more donating twisted diradical in solution, so that the oxidation potential can be controlled by heating/cooling. This is the first exampl

The gold-catalysed annulation of conjugated alkynes bearing an azido group with arenes gave annulated [<i>c</i>]carbazoles. Using benzene, pyrrole, and indole derivatives as the nucleophiles, benzo[<i>c</i>]-, pyrrolo[2,3-<i>c</i>]-, and indolo[2,3-<i>c</i>]carbazoles were produced, respectively. The reaction proceeded through pyrrole and benzene ring construction accompanied by the formation of two carbon-carbon and one carbon-nitrogen bond and the cleavage of two aromatic C-H bonds. The mechan