Radical Single-Molecule Junctions

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(33), P. 18182 - 18204

Published: Aug. 9, 2023

Radicals are unique molecular systems for applications in electronic devices due to their open-shell structures. can function as good electrical conductors and switches circuits while also holding great promise the field of spintronics. However, it is both challenging create stable, persistent radicals understand properties junctions. The goal this Perspective address dual challenge by providing design principles synthesis stable relevant junctions, well offering current insight into single-molecule devices. By exploring chemical physical established radical systems, we will facilitate increased exploration development radical-based systems.

Language: Английский

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A highly efficient open-shell singlet luminescent diradical with strong magnetoluminescence properties

Light Science & Applications, Journal Year: 2023, Volume and Issue: 12(1)

Published: Nov. 14, 2023

Abstract Developing open-shell singlet (OS) diradicals with high luminescent properties and exceptional single-molecule magnetoluminescence (ML) performance is extremely challenging. Herein, we propose a concept to enhance efficiency by adjusting the donor conjugation of OS diradicals, thereby achieving highly diradical, DR1, outstanding stability making it viable option for use in emitting layer organic light-emitting diodes (OLEDs). More importantly, 0.5 wt%-DR1 doped film demonstrates significant properties. A giant ML value 210% achieved at magnetic field 7 T, showing great potential DR1 magneto-optoelectronic devices.

Language: Английский

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Synthesis and Reactivity of a Dialane‐Bridged Diradical

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(18)

Published: Feb. 28, 2024

Abstract Radicals of the lightest group 13 element, boron, are well established and observed in numerous forms. In contrast to radical chemistry involving heavier elements (aluminum, gallium, indium, thallium) remains largely underexplored, primarily attributed formidable synthetic challenges associated with these elements. Herein, we report synthesis isolation planar twisted conformers a doubly CAAC (cyclic alkyl(amino)carbene)‐radical‐substituted dialane. Extensive characterization through spectroscopic analyses X‐ray crystallography confirms their identity, while quantum chemical calculations support open‐shell nature provide further insights into electronic structures. The dialane‐connected diradicals exhibit high susceptibility oxidation, as evidenced by electrochemical measurements reactions o ‐chloranil variety organic azides. This study opens previously uncharted class dialuminum systems study, broadening scope diradical its potential applications.

Language: Английский

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Unlocking Biradical Character in Diborepins

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(10), P. 6506 - 6515

Published: Feb. 29, 2024

Systems that possess open- and closed-shell behavior attract significant attention from researchers due to their inherent redox charge transport properties. Herein, we report the synthesis of first diborepin biradicals. They display tunable biradical character based on steric electronic profile stabilizing ligand resulting geometric deviation core planarity. While there are numerous all-carbon-based systems, boron-based compounds comparatively rare, particularly ones in which radical sites disjointed. Calculations using density functional theory (DFT) multireference methods demonstrate fused scaffold exhibits high character, up 95%. Use a nonsterically demanding diaminocarbene promotes planarization pentacyclic framework, synthetic realization containing dibora-quinoidal core, possesses ground state thermally accessible triplet state. The biradicals were structurally authenticated characterized by both solution solid-state electron paramagnetic resonance (EPR) spectroscopy. Half-field transitions observed at low temperatures (about 170 K), confirming presence Initial reactivity studies led isolation structural characterization bis(borepin hydride) dianion).

Language: Английский

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Diradicaloid Boron‐Doped Molecular Carbons Achieved by Pentagon‐Fusion

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 62(51)

Published: Nov. 4, 2023

Molecular carbons (MCs) are molecular cutouts of carbon materials. Doping with heteroatoms and constructing open-shell structures two powerful approaches to achieve unexpected unique properties MCs. Herein, we disclose a new strategy design boron-doped MCs (BMCs), namely by pentagon-fusion an organoborane π-system. We synthesized diradicaloid BMC molecules that feature C24 B C38 π-skeletons containing pentagonal ring. A thorough investigation reveals such not only leads their local antiaromaticity, but also incorporates internal quinoidal substructure thereby induces singlet diradical states. Moreover, fully fused enable efficient π conjugation, which is expanded over the whole frameworks. Consequently, some intriguing physical achieved, as narrow energy gaps, very broad light absorptions, superior photothermal capability, along excellent photostability. Notably, solid molecule exhibits absorption covers range 300-1200 nm efficiency 93.5 % for solar-driven water evaporation, thus demonstrating potential BMCs high-performance organic

Language: Английский

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Boryl-substituted low-valent heavy group 14 compounds

Chemical Society Reviews, Journal Year: 2023, Volume and Issue: 53(1), P. 361 - 379

Published: Dec. 12, 2023

This review focuses on the low-valent heavy group 14 compounds stabilized by N-heterocyclic boryl ligands and their applications in activation of small molecules inert chemical bonds.

Language: Английский

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Progress of Indeno-type Organic Diradicaloids

Chemical Research in Chinese Universities, Journal Year: 2023, Volume and Issue: 39(2), P. 161 - 169

Published: March 7, 2023

Language: Английский

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CH‐Functionalization of Heterocycles with the Formation of C−O, C−N, C−S/Se, and C−P Bonds by Intermolecular Addition of Heteroatom‐Centered Radicals

Advanced Synthesis & Catalysis, Journal Year: 2023, Volume and Issue: 365(11), P. 1714 - 1755

Published: April 12, 2023

Abstract In the last decade, free radicals have found a wide application in functionalization of unsaturated compounds, such as alkenes, alkynes, and arenes, via free‐radical addition to carbon‐carbon π‐bonds. these processes, intermolecular attack on aromatic substrates represents challenge due relatively high resistance π‐system reactions comparison alkene C=C bonds. The heterocycles is especially interesting diversity their structures chemical properties well importance for medicinal chemistry, agrochemistry, materials science. Addition C‐centered widely known Minisci‐type well‐reviewed. this paper, we summarized main achievements less explored group processes: by heteroatom‐centered (O‐, N‐, S‐/Se‐, P‐radicals) with emphasis papers published after 2010. Literature analysis revealed strong trend towards usage electrochemistry photoredox‐catalysis generation recent years. remaining fundamental problem field lack experimental support proposed mechanisms frequent existence several plausible reaction pathways. progress mechanistic studies can significantly improve prediction optimal conditions depending structure.

Language: Английский

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NHC-catalyzed enantioselective radical reactions of enal and pyridinium salt: mechanism and origin of regio- and stereoselectivities

Catalysis Science & Technology, Journal Year: 2023, Volume and Issue: 13(18), P. 5259 - 5266

Published: Jan. 1, 2023

The origin of regio- and stereoselectivities NHC-catalyzed enantioselective radical reactions an enal a pyridinium salt has been explored via theory for the first time.

Language: Английский

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An Isolable Phosphinogermylyne as a Synthon of One‐Coordinate Ge^I Radical

Chinese Journal of Chemistry, Journal Year: 2023, Volume and Issue: 42(7), P. 736 - 742

Published: Nov. 27, 2023

Comprehensive Summary Reduction of chlorogermylene M s Fluind t Bu ‐GeCl 1 with potassium graphite (KC 8 ) afforded putative germylyne radical ‐Ge 2 as confirmed by electron paramagnetic resonance (EPR) spectroscopy. However, it slowly decayed via C—H bond activation at the fluorenyl moiety to yield a bis(germylene) 3 room temperature. By using Lewis base stabilize unoccupied p orbital Ge I center, acyclic two‐coordinate radicals ‐Ge(I Me4 4 (I = 1,3,4,5‐tetramethyl‐imidazolin‐2‐ylidene), i Pr 5 1,3‐diisopropyl‐4,5‐dimethyl‐imidazolin‐2‐ylidene), ‐Ge(PMe 6 were isolated in crystalline forms. The unpaired — mainly resides 4p revealed EPR spectroscopic studies and theoretical calculations. Interestingly, facile ligand exchange PMe was observed afford , respectively. Moreover, phosphinogermylyne reacted PhEEPh (E S, Se), 4‐tetrabutylphenylacetylene (Ar'CCH), [CpMo(CO) ] n SnH furnish germylenes ‐GeEPh S 7 Se ), ‐GeCH=CHAr’ 9 complex ‐Ge≡Mo(CO) Cp 10 Ge(IV) compound ‐GeH Sn 11 reactivity demonstrate that can act synthon one‐coordinate attributing labile coordination trimethylphosphine.

Language: Английский

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