A highly modular synthesis of BNB- and BOB-doped phenalenyls is presented. Treatment of the 1,8-naphthalenediyl-bridged boronic acid anhydride 1 with LiAlH4/Me3SiCl afforded the corresponding 1,8-n...

BNB-Doped Phenalenyls: Modular Synthesis, Optoelectronic Properties, and One-Electron Reduction.

Recent advances in the development of pure organic white light emitters

Featuring the atypical photophysical characteristics of dual or multiple radiative decay pathways, anti-Kasha emissive materials have drawn increasing interests in the fields of organic light-emitting diodes, sensing, bioimaging, anti-counterfeiting, information encryption, etc. The investigations on anti-Kasha emissions have been motivated by fundamental and practical demands. However, most organic luminescence materials are restricted by Kasha's rule and only show a single-wavelength emission band in the lowest excited state. To develop anti-Kasha emissive materials, various design strategies, such as ESIPT, excimers, self-assembly, isomerization, and polymerization, were proposed case by case. In this review, recent progress of the anti-Kasha emitters has been summarized in depth according to their relative mechanisms: isomerization balancing, excited state balancing and emissive building block combination. In addition, their precise molecular design strategies, photophysical properties, and applications have also been reported. We hope that this brief introduction will inspire more researchers to focus on this promising field and promote the development of anti-Kasha emissive materials.

Breaching Kasha's rule for dual emission: mechanisms, materials and applications

Access to dithiophene-fused oxadiborepins and the first azadiborepins attained via a modular synthesis route are presented. The new compounds emit intense blue light, some of which demonstrate fluorescence quantum yields close to unity. Cyclic voltammetry (CV) revealed electrochemically reversible one-electron reduction processes. The weak aromatic character of the novel 1,2,7-azadiborepin ring is demonstrated with in-depth theoretical investigations using nucleus-independent chemical shift (NICS) scans and anisotropy of the induced current density (ACID) calculations.

https://www.onlinelibrary.wiley.com/doi/pdf/10.1002/ange.202100295

Dithiophene-Fused Oxadiborepins and Azadiborepins: A New Class of Highly Fluorescent Heteroaromatics

Boron-nitrogen-doped π-conjugated systems have been regarded as a type of organic materials with exceptional electronic and optical properties, which makes them promising in optoelectronic devices. Due to the isoelectronic relationship...

Multiple-boron-nitrogen (multi-BN) doped π-conjugated systems for optoelectronics

Realizing solution-processed heterostructures is a long-enduring challenge in halide perovskites because of solvent incompatibilities that disrupt the underlying layer. By leveraging the solvent dielectric constant and Gutmann donor number, we could grow phase-pure two-dimensional (2D) halide perovskite stacks of the desired composition, thickness, and bandgap onto 3D perovskites without dissolving the underlying substrate. Characterization reveals a 3D–2D transition region of 20 nanometers mainly determined by the roughness of the bottom 3D layer. Thickness dependence of the 2D perovskite layer reveals the anticipated trends for n-i-p and p-i-n architectures, which is consistent with band alignment and carrier transport limits for 2D perovskites. We measured a photovoltaic efficiency of 24.5%, with exceptional stability of T99 (time required to preserve 99% of initial photovoltaic efficiency) of >2000 hours, implying that the 3D/2D bilayer inherits the intrinsic durability of 2D perovskite without compromising efficiency. Description Pure perovskite topcoats Two-dimensional (2D) halide perovskite passivation layers grown on three-dimensional (3D) perovskite can boost the power conversion efficiency (PCE) of solar cells, but spin-coating of these layers usually forms heterogeneous 2D phases or only ultrathin layers. Sidhik et al. found that solvents with the appropriate dielectric constant and donor strength could grow phase-pure 2D phases of controlled thickness and composition on 3D substrates without dissolving them. Solar cells maintained a peak PCE of 24.5% for 2000 hours with less than 1% degradation under continuous light at 55°C and 65% relative humidity. —PDS Solvents enable growth of phase-pure two-dimensional perovskites without dissolving three-dimensional perovskite substrates.

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Deterministic fabrication of 3D/2D perovskite bilayer stacks for durable and efficient solar cells

A series of novel bis-BN-naphthalene-fused oxepin derivatives were synthesized via a Pd-catalyzed tandem reaction from brominated 2,1-borazaronaphthalenes and cis-bis(boryl)alkenes. X-ray crystallographic analysis revealed that bis-BN-naphthalene-fused oxepins feature a planar framework. The electronic and photophysical properties of the novel BN-naphthalene-fused oxepins were investigated by UV–vis and fluorescence spectroscopies and density functional theory (DFT) calculations, which disclosed the distinct electronic and photophysical properties of the analogous hydrocarbon system. Interestingly, dual-fluorescent emissions were observed upon dissolving N-substituted derivatives 10–14 in dimethyl sulfoxide. Tunable emission colors especially for white-light emissions can be achieved by controlling the ratio of solvents, concentration, or temperature using only a single-molecule compound.

Wenbin Li

Papers

Deterministic fabrication of 3D/2D perovskite bilayer stacks for durable and efficient solar cells

Synthesis of bis-BN-Naphthalene-Fused Oxepins and Their Photoluminescence Including White-Light Emission

Improving the sensitivity and selectivity of sulfonamides electrochemical detection with double-system imprinted polymers.

Influence of Chemical Engineering, Photodoping and Lattice Distortions on the Optoelectronic Properties of Multilayered Perovskites