Carbon-based Biradicals: Structural and Magnetic Switching

Chemical Reviews, Journal Year: 2023, Volume and Issue: 123(24), P. 13952 - 13965

Published: Nov. 10, 2023

Sterically hindered C═C double bonds often deform into a bent or twisted geometry. Thus, many overcrowded ethylenes anthraquinodimethanes can adopt multiple conformations, such as folded form form, which are interconvertible under the application of external stimuli. A perpendicular with biradical character also be adopted when designed to incorporate stable carbon-based radical unit, is involved in stimuli-responsive magnetic switching accompanied by structural change. This review focuses on recent advances development strained π-electron systems and reveals factors that affect mutual interconversion behavior. The energy barrier for conformational isomers affected tricyclic skeleton bulky substituents bonds, whereas relative stability increases additional insertion 9,10-anthrylene units bonds.

Language: Английский

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Redox-Switchable Aromaticity in a Helically Extended Indeno[2,1-c]fluorene

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(28), P. 19168 - 19176

Published: July 2, 2024

Molecular switches have received major attention to enable the reversible modulation of various molecular properties and been extensively used as trigger elements in diverse fields, including machines, responsive materials, photopharmacology. Antiaromaticity is a fascinating property that has attracted not only significant fundamental interest but also increasingly relevant different applications, particular organic (opto)electronics. However, designing systems which (anti)aromaticity can be judiciously reversibly switched ON OFF remains challenging. Herein, we report helicene featuring an indenofluorene-bridged bisthioxanthylidene novel switch wherein simultaneous two-electron (electro)chemical redox process allows highly its (anti)aromatic character. Specifically, two thioxanthylidene rotors, attached initially aromatic indenofluorene scaffold via overcrowded alkenes, adopt anti-folded structure, upon oxidation convert singly bonded, twisted conformations. This associated with (chir)optical changes importantly results formation fully conjugated, formally antiaromatic as-indacene motif helical core switch. proceeds without buildup radical cation intermediates thus enables switching geometry, aromaticity, absorbance, chiral expression under ambient conditions, evidenced by NMR, UV–vis, CD, (spectro)electrochemical analyses, supported DFT calculations. We expect this concept extendable wide range robust antiaromatic–aromatic provide basis for structure these inherently polycyclic π-scaffolds.

Language: Английский

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Synthesis and structural evaluation of closed-shell folded and open-shell twisted hexabenzo[5.6.7]quinarene

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(48), P. 7379 - 7382

Published: Jan. 1, 2023

We describe the synthesis and characterization of hexabenzo[5.6.7]quinalene demonstrate spin-state switching induced by a combination chemical oxidation/reduction thermal stimulation.

Language: Английский

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Domino-Redox Reaction Induced by a Conformational Change Based on Dithiin Bisquinodimethane Skeleton

Springer theses, Journal Year: 2025, Volume and Issue: unknown, P. 111 - 146

Published: Jan. 1, 2025

Language: Английский

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Heptene End-capped Thiele Hydrocarbons with Tunable Configuration and Emission and On-surface Transformation via Annulation

Chemical Communications, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

We report a para -quinodimethane skeleton ( p -QDM)-based polycyclic aromatic hydrocarbon (PAH) with heptenes as end-capping groups and F-substituents in the central six-membered ring.

Language: Английский

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Open‐Shell States in Dynamic Diradicaloids

ChemPlusChem, Journal Year: 2025, Volume and Issue: unknown

Published: March 18, 2025

Abstract The open‐shell organic and carbon‐based systems, with either a doublet, triplet or higher spin‐states, play key role in contemporary research, opening potential applicability for several crucial fields. Among those derivatives, specific attention has been given to p ‐phenylene‐based systems derived from the original Thiele hydrocarbon. These stabilize an diradicaloid resonance structure thermally accessible state are quinone‐benzene (Clar's sextet) equilibrium. In our discussion, we very carefully choose examples which focus on fundamental derivatives that merge diatropic subunits, ready two unpaired electrons via dynamic modulation of geometry. This process provides additional factor energy aromatics, mostly responsible stabilization electrons.

Language: Английский

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Diverse redox-mediated transformations to realize the para-quinoid, σ-bond, and ortho-diphenoquinoid forms

Nature Communications, Journal Year: 2025, Volume and Issue: 16(1)

Published: May 8, 2025

Language: Английский

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Introducing Phosphorus into the Overcrowded Thiele’s hydrocarbon Family: Unveiling Contorted Main Group Diradicaloids with Dynamic Redox Behavior

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(47)

Published: Aug. 19, 2024

Abstract Thiele's Hydrocarbons (THs) featuring a 9,10‐anthrylene core with switchable geometric and electronic configurations offer exciting possibilities in advanced functional materials. Despite significant advances main group‐based diradicaloids contemporary chemistry, group THs containing an anthrylene cores have remained elusive, primarily due to the lack of straightforward synthetic strategies inherent high reactivity these species. In this study, we utilize anthracene‐based phosphine synthon demonstrate, for first time, facile high‐yielding strategy robust P‐functionalized overcrowded ethylenes (OCEs) within TH family. These OCEs feature non‐symmetric environment, incorporating (thio) xanthyl phosphaalkene termini. We systematically probe structures derivatives illustrate impact isolobal motif on quinoidal/diradicaloid character. Notably, compounds exhibit dynamic redox behavior, leading orthogonally twisted conformational changes upon oxidation, kinetically locked redox‐couple.

Language: Английский

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Domino‐Redox Reaction Induced by An Electrochemically Triggered Conformational Change

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(1)

Published: Nov. 16, 2023

The concept of a domino-type reaction has been applied in wide range fields such as synthetic organic chemistry, material engineering, and life science. To extend the domino to redox we designed synthesized dimeric quinodimethane (QD) with nonplanar dithiin spacer. domino-redox properties can be activated by raising temperature, based on thermally equilibrated twisted conformation QD, which higher HOMO level that is more readily oxidized. After one QD unit oxidized (trigger), steric repulsion electronic interaction between electrophores make neighboring adopt (domino process), facilitates following oxidation. Thus, was achieved for first time change due drastic molecular conformation.

Language: Английский

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Selective Synthesis of New Hexaalkylbicyclo[1.1.1]Pentasilanes with Improved Solubility

Zeitschrift für anorganische und allgemeine Chemie, Journal Year: 2024, Volume and Issue: 650(11-12)

Published: May 22, 2024

Abstract Molecular structures and properties of molecular silicon clusters oligo/polysilanes depend on the substituents skeletons. Herein, we report synthesis new bicyclo[1.1.1]pentasilanes (BPS) having various alkyl (ethyl, i Bu, or 2‐ethylbutyl) at bridge atoms. All BPS are characterized by NMR spectroscopy, MS spectrometry, single crystal X‐ray diffraction (sc‐XRD) analysis. Introduction longer groups unsymmetrical substitution positions skeleton substantially improve solubility toward organic solvents, while electronic similar to each other.

Language: Английский

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