Extended conjugated borenium dimers <i>via</i> late stage functionalization of air-stable borepinium ions

Adachi, Yoshinori; Arai, Fuka; Jäkle, Frieder

doi:10.1039/d0cc02514c

Cited by 31 publications

(9 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In 2019, we reported the molecular structures of the first examples of cationic borepins, borepinium ions (Figure 1B) [6] . Recently, fused diborepinium ions were synthesized and exhibited luminescent properties as a result of extended conjugation [7] . Despite the ongoing interest in boron radicals [8] and anions, [9] the chemical synthesis and structural authentication of reduced, nucleophilic borepins are hitherto unknown (Figure 1C).…”

Section: Figurementioning

confidence: 99%

“…[6] Recently, fused diborepinium ions were synthesized and exhibited luminescent properties as a result of extended conjugation. [7] Despite the ongoing interest in boron radicals [8] and anions, [9] the chemical synthesis and structural authentication of reduced, nucleophilic borepins are hitherto unknown (Figure 1C). This is likely due to their inherent high reactivity and the challenging nature of the experimental chemistry.…”

Section: Boron-doped Polycyclic Aromatic Hydrocarbons (B-pahs)mentioning

confidence: 99%

See 1 more Smart Citation

Isolation of Stable Borepin Radicals and Anions

et al. 2022

View full text Add to dashboard Cite

Borepin, a 7‐membered boron‐containing heterocycle, has become an emerging molecular platform for the development of new materials and optoelectronics. While electron‐deficient borepins are well‐established, reduced electron‐rich species have remained elusive. Herein we report the first isolable, crystalline borepin radical (2 a, 2 b) and anion (3 a, 3 b) complexes, which have been synthesized by potassium graphite (KC8) reduction of cyclic(alkyl)(amino) carbene‐dibenzo[b,d]borepin precursors. Borepin radicals and anions have been characterized by EPR or NMR, elemental analysis, X‐ray crystallography, and cyclic voltammetry. In addition, the bonding features have been investigated computationally using density functional theory.

show abstract

Section: Figurementioning

confidence: 99%

Section: Boron-doped Polycyclic Aromatic Hydrocarbons (B-pahs)mentioning

confidence: 99%

Isolation of Stable Borepin Radicals and Anions

et al. 2022

View full text Add to dashboard Cite

show abstract

“…The resulting products served as precursors to borepinium ions. 35 During studies of silepins featuring bulky cyclic motifs, treatment of the linear trimer of bicyclo[2.2.2]octene 32 36 with 4-5 equivalents of butyllithium, followed by reaction with dichlorodimethylsilane afforded compound 33 in moderate yield. 13 Further derivatives bearing various combinations of substituents (e.g.…”

Section: © Author(s)mentioning

confidence: 99%

Chemistry of silepins and their analogs containing group 14 elements

Janosik¹,

Berg²

2021

Arkivoc

View full text Add to dashboard Cite

show abstract

“…An important recent finding in this regard was that the combination of furan rings with strongly electron-withdrawing groups substantially improves their resistance to oxidative degradation by lowering the compound’s highest occupied molecular orbital (HOMO) energy and therefore enhancing its overall stability. ,− The doping of conjugated π systems with trivalent boron atoms has emerged as an effective strategy to produce novel compounds with intriguing properties and functions. − …”

Section: Introductionmentioning

confidence: 99%

Boron-Doped α-Oligo- and Polyfurans: Highly Luminescent Hybrid Materials, Color-Tunable through the Doping Density

et al. 2021

View full text Add to dashboard Cite

Doping of π-conjugated polymers or molecular compounds with trivalent boron atoms has recently emerged as a viable strategy to produce new materials with intriguing properties and functions. The combination of boron with furan moieties has been only scarcely explored so far, although the resulting furan-based materials have several notable features, including favorable optoelectronic properties and improved sustainability. Herein, we investigate the doping of α-polyfurans with a varying number of boron atoms. A series of poly(oligofuran boranes) and oligofuran-bridged bisboranes have been prepared via microwave-assisted Stille-type catalytic cross-coupling protocols. In the solid-state structures of the molecular compounds, the furan and the borane moieties exhibit a strictly coplanar arrangement; the derivative with a pentafuran bridge forms a dimeric structure in the solid state. All new compounds show considerable absorption and emission features in the visible range that arise from π–π* transitions in the oligofurylborane backbone. They are highly luminescent with quantum yields between 89 and 97% for the bisboranes and up to 87% for the difuran-bridged polymer PB2F. Their emission colors can be effectively tuned in the visible range from blue to orange via the length of the oligofuran linker. Spectroelectrochemical investigations on the difuran-bridged bisborane BB2F and polymer PB2F revealed fully reversible stepwise reductions to the respective radical anion (polaron), with absorption features in the near-infrared (NIR) region, and subsequently to a dianion (dipolaron). Overall, the doping of α-oligofurans with boron leads to a decrease of the frontier orbital energies, a reduction of the electronic band gap, and the formation of very robust and oxidatively stable materials.

show abstract

Extended conjugated borenium dimers via late stage functionalization of air-stable borepinium ions

Abstract: Conjugated dimeric borenium ions exhibit red-shifted absorptions, enhanced emission, and dramatically lower LUMO energies.

Cited by 31 publications

References 43 publications

Isolation of Stable Borepin Radicals and Anions

Isolation of Stable Borepin Radicals and Anions

Chemistry of silepins and their analogs containing group 14 elements

Boron-Doped α-Oligo- and Polyfurans: Highly Luminescent Hybrid Materials, Color-Tunable through the Doping Density

Contact Info

Product

Resources

About