Redox-Active Boron Clusters

Accounts of Chemical Research, Год журнала: 2024, Номер 57(9), С. 1310 - 1324

Опубликована: Апрель 15, 2024

ConspectusIn this Account, we discuss our group's research over the past decade on a class of functionalized boron clusters with tunable chemical and physical properties, an emphasis accessing controlling their redox behavior. These can be thought as three-dimensional aromatic systems that have distinct behavior photophysical properties compared to two-dimensional organic counterparts. Specifically, lab has studied highly tunable, multielectron B12(OR)12 applied these molecules in various settings. We first spectroscopic electrochemical characterization oxidation states, followed by use catholytes and/or anolytes flow batteries dopants conjugated polymers. Additionally, high oxidizing potential visible light-absorbing nature fluoroaryl-functionalized been leveraged group generate weakly coordinating, photoexcitable species promote photooxidation chemistry.We further translated solution-phase studies solid state using precursor [B12(OH)12]2– cluster robust building block for hybrid metal oxide materials. shown act thermally stable cross-linking material, which enhances electron transport between nanoparticles. structural motif create TiO2- WO3-containing materials showed promising photocatalysts electroactive supercapacitors. Building concept, later discovered B12(OCH3)12, smallest family, could retain its state, previously unseen phenomenon. successfully harnessed unique solid-state energy storage implementing cathode-active material Li-ion prototype cell device. Recently, also explored how tune other than synthesizing library vertex-differentiated containing both B-OR B-halogen groups. Due additive qualities different functional groups cluster, allow access region potentials inaccessible fully substituted closo-dodecaborate alkoxy-based derivatives.Lastly, into smaller-sized redox-active polyhedral boranes (B6- B10-based cores). Interestingly, show significantly less stability reversibility dodecaborate-based While exploring functionalization closo-hexaborate derivates (i.e., [B6R6Hfac]−), observed oxidative decomposition pathways system. Consequently, instability useful alkyl boronate esters via selective oxidation. closo-decaborate platform electrophilic [B10H13]+ capable directly borylating arene compounds regioselectivity. Upon arylated decaborate clusters, synthesized aryl esters, establishing generality deconstruction concept.Overall, work shows are appealing molecules, fundamental understudied property constructing novel well producing reagents small molecule synthesis.

Язык: Английский

---

A variable bidentate traceless directing group for nickel-catalyzed regioselective B–H poly-chalcogenation of o-carboranes

Inorganic Chemistry Frontiers, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

A nickel-catalyzed direct cage B–H poly-chalcogenation of icosahedral carborane clusters, enabled by a variable bidentate 8-aminoquinoline traceless directing group, has been developed under oxidant-free and weakly basic conditions.

Язык: Английский

---

Iridium-catalyzed selective arylation of B(6)–H of 3-aryl-o-carboranes with arylboronic acid via direct B–H activation

Chemical Communications, Год журнала: 2024, Номер 60(9), С. 1124 - 1127

Опубликована: Янв. 1, 2024

This work discloses an iridium-catalyzed selective arylation of B(6)–H 3-Ar- o -carboranes with arylboronic acid via direct B–H activation for the first time.

Язык: Английский

---

Synthesis and cluster structure distortions of biscarborane dithiol, thioether, and disulfide

Dalton Transactions, Год журнала: 2024, Номер 53(10), С. 4444 - 4450

Опубликована: Янв. 1, 2024

Biscarborane dithiol and its bis(methyl)thioether feature exceedingly long intracluster C–C bond lengths, consistent with the increased π-backdonation of sulfur atom lone pairs into electron-accepting boron cluster.

Язык: Английский

---

Combustion Resistant Borohydrides and Their Chemical Interactions with Li-Metal Surfaces: An Experimental and Theoretical Study

ACS Central Science, Год журнала: 2025, Номер unknown

Опубликована: Апрель 23, 2025

Язык: Английский

---

The 12-Ethynylmonocarba-closo-dodecaborate Anion: A Ligand for Metal Alkynide Complexes (M = Li, Na, Ca, Zn)

Inorganic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Май 8, 2025

We report the first isolation of metal alkynide complexes (2a-d) incorporating lithium, sodium, calcium and zinc based on monocarborane endo/exo-dianionic framework [CB11H11-12-C≡C]2-. These are synthesized via deprotonation terminal alkynes optimized using calcium, hexamethyldisilazide bases to achieve enhanced yields crystal stability. X-ray crystallography NMR spectroscopy reveal unique coordination geometries, including a rare chair-shaped Li4C2O2 unit in 2a, multinuclear units 2b-c, hexagonal Zn3C3 2d. Subsequent nucleophilic reactions with benzophenone afford propargylic alcohols (3) high efficiency, demonstrating their utility selective synthetic routes for complex molecular assembly. This work not only highlights reactivity alkali alkaline-earth metals acetylides but also offers valuable insights into structural characteristics potential applications advanced materials catalytic systems.

Язык: Английский

---

Noncatalyzed Intramolecular B–N and B–O Cross-Coupling of “Inert” Carboranes Lead to the Formation of an Unusual Oxoborane, via Reversible Cluster C–B Bond Scission

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Май 13, 2025

Polyhalogenated closo-12-vertex carborane anions are thought to be inert species incapable of participating in direct B-X substitution reactions. Here, we show that this is not true and such can easily coaxed into intramolecular cross-coupling cyclizations without the need for a catalyst. When cage C-tethered O N-heteroallylic generated, variety cyclized products formed high yield under mild conditions. Additionally, even neutral nucleophiles, as pyridine moiety, undergo facile chemistry these reactions dependent on countercation. Serendipitously, also found when attempted with acetamide derivatives, an unprecedented cluster C-B bond scission reaction occurs, producing oxoborane stabilized by multicentered bonding. Amazingly molecule protonated, leading reformation reorganization, process reversible.

Язык: Английский

---

Palladium-Catalyzed Regioselective B(3,4,5,6)–H Tetra-Arylation of o-Carboranes

Inorganic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Май 21, 2025

A transition-metal-catalyzed iterative multiple cage B-H activation reaction for constructing multifunctionalization of o-carboranes in one pot is challenging. Herein, palladium-catalyzed regioselective tetra-arylation a wide range C(1)-N-aryl-o-carboranyl amides with aryl iodides has been developed. variety B(3,4,5,6)-tetra-arylated were synthesized good-to-excellent yields. Moreover, the mono-, di-, and triarylated intermediate products isolated, exact structures determined by NMR, high-resolution mass spectrometry, X-ray analysis, which provide rationale that order introduction groups into o-carborane B(4) > B(5) B(3)/B(6). This protocol represents powerful synthetic method polyfunctionalization derivatives under very mild simple conditions, offers valuable reference design synthesis molecular propellers based on carboranes.

Язык: Английский

---

Rhodium-Catalyzed Selective Chalcogenation of B(4)-H of o-Carboranes

Inorganic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Июнь 4, 2025

A rhodium-catalyzed universal protocol for selective chalcogenation of B(4)-H o-carboranes with diaryl diselenides, disulfides, and diphenyl ditelluride has been developed the first time. series B(4)-Se/S/Te-o-carborane derivatives decorated various kinds active groups have synthesized excellent yields regioselectivity. Based on control experiments, a plausible mechanism involving radical direct oxidative addition process is proposed. This work would be an important reference design new reactions boron clusters.

Язык: Английский

---

Redox-Active Carboranyl Diphosphine as an Electron and Proton Transfer Agent

Inorganic Chemistry, Год журнала: 2024, Номер 63(32), С. 15053 - 15060

Опубликована: Июль 27, 2024

In this work, we report the first example of PCET reactivity for a boron cluster compound, zwitterionic nido-carboranyl diphosphonium derivative 7-P(H)tBu2-10-P(H)iPr2-nido-C2B10H10. This main-group reagent efficiently transfers two electrons and protons to quinones yield hydroquinones regenerate neutral closo-carboranyl diphosphine, 1-PtBu2-2-PiPr2-closo-C2B10H10. As have previously reported conversion diphosphine into nido- upon reaction with main group hydrides, transformation herein represents complete synthetic cycle metal-free reduction quinones, redox-active carboranyl scaffold acting as mediator. The proposed mechanism reduction, based on pKa determination, electrochemical studies, kinetic isotope effect involves electron transfer from quinone coupled delivery protons.

Язык: Английский

---