Π-conjugated Systems Research Articles

A Study of 2,3,4,5-tetrakis(2-thienyl)-1-monophosphole and 2,3,4,5-tetrakis(2-thienyl)-1-monophosphaferrocene as building blocks for π-conjugated systems

The synthesis of tetraaryl-substituted 1-monophospholes and 1-monophosphaferrocenes, bearing 4-bromophenyl and 2-thienyl substituents at the PCα carbon atoms are described. It was shown that the reaction of n-octyl chloride with a mixture of sodium 1,2,3-tri- and 1-monophospholides results in the exclusive formation of new luminescent 1-n-octyl-1-monophospholes. All novel compounds have been fully characterized by NMR spectroscopy and mass-spectrometry, their optical and electrochemical behaviors have been elucidated. Phosphaferrocene-based compounds exhibit higher oxidation stability and higher HOMO-LUMO separation compared to the corresponding 1-monophosphole units.

A mitochondrial targeted dual ratiometric near-infrared fluorescent probe based on ICT effect for the detection of SO2 derivative and its bioimaging

SO2 derivatives play an important role in many metabolic processes, excessive ingestion of them can lead to serious complications of various diseases. In this work, a novel dual ratiometric NIR fluorescent probe XT-CHO based on ICT effect was synthesized for detecting SO2 derivative. In the design of the probe, the α, β-unsaturated bond formed between benzopyran and coumarin was used as the reaction site for SO2, meanwhile, the extended π-conjugate system promoted maximum emission wavelength of the probe up to 708 nm. Notably, the probe exhibited high selectivity and sensitivity for detecting SO2, the limit of detection reached 2.13 nM and 58.5 nM in fluorescence spectra and UV–Vis absorption spectra, respectively. The reaction mechanism of SO2 and XT-CHO had been verified by 1H NMR, ESI-MS spectra and DFT calculation. Moreover, the probe was successfully applied in detecting endogenous and exogenous SO2 in living cells and proved possessed the mitochondrial targeted ability.

Erythrocyte-like ACET anchored on graphitic carbon nitride with activating π-conjugated electron transfer for enhanced photocatalytic hydrogen production

Activating π-conjugated electron transfer in graphitic carbon nitride (g-C3N4), not only enhances the absorption of solar light, but also breaks through energy barrier, sequentially leading to increased photocatalytic hydrogen production. However, g-C3N4 is prone to agglomeration, wide bandgap, weak absorption of visible light, poor electrical conductivity and so on, which seriously restrict its photocatalytic performance, therefore activating π-conjugated electron transfer is confronted with great challenges. Herein, we show that activating π-conjugated electron transfer by breaking tri-s-triazine unit of g-C3N4 through a simple one-step gas template method. As a result, the best performed CN-4 sample exhibits an outstanding hydrogen production rate of 1282 μmol h−1 g−1, which is 455% higher than that of the pristine g-C3N4 (282 μmol h−1 g−1). Moreover, the density functional theory (DFT) calculations suggest that the original π-conjugated electron equilibrium system has been a significant transformation by C-doping. The results present a new direction of thought that utilizes π-conjugated electron transfer to enhance the photocatalytic hydrogen production by breaking tri-s-triazine unit.

Intermolecular Hydrogen Bonding Networks Stabilized Organic Supramolecular Cathode for Ultra-High Capacity and Ultra-Long Cycle Life Rechargeable Aluminum Batteries.

Rechargeable aluminum batteries (RABs) are a promising candidate for large-scale energy storage, attributing to the abundant reserves, low cost, intrinsic safety, and high theoretical capacity of Al. However, the cathode materials reported thus far still face challenges such as limited capacity, sluggish kinetics, and undesirable cycle life. Herein, we propose an organic cathode benzo[i] benzo[6,7] quinoxalino [2,3-a] benzo [6,7] quinoxalino [2,3-c] phenazine-5,8,13,16,21,24-hexaone (BQQPH) for RABs. The six C=O and six C=N redox active sites in each molecule enable BQQPH to deliver a record ultra-high capacity of 413 mAh g-1 at 0.2 A g-1. Encouragingly, the intermolecular hydrogen bonding network and π-π stacking interactions endow BQQPH with robust structural stability and minimal solubility, enabling an ultra-long lifetime of 100,000 cycles. Moreover, the electron-withdrawing carbonyl group induces a reduction in the energy level of the lowest unoccupied molecular orbital and expands the π-conjugated system, which considerably enhances both the discharge voltage and redox kinetics of BQQPH. In situ and ex situ characterizations combined with theoretical calculations unveil that the charge storage mechanism is reversible coordination/dissociation of AlCl2 + with the N and O sites in BQQPH accompanied by 12-electron transfer. This work provides valuable insights into the design of high-performance organic cathode materials for RABs.

Delaying crystallization and anchoring the grain boundaries defects via π-π stacked molecules for efficient and stable wide-bandgap perovskite solar cells

Owing to the easy migration of halogen ions in wide-bandgap perovskite, it will lead to the formation of a large number of uncoordinated Pb2+ to form deep-level defects, which seriously affects the power conversion efficiency (PCE) and stability of wide-bandgap perovskite solar cells (PSCs). The introduction of additives has been recognized as an effective method to improve these defects, especially Lewis acid-base additives. Herein, Lewis base molecule dibenzofuran (DBF) with π-conjugated system, which can form π-π stacked dimer, is used as a perovskite additive. The detailed crystallization process of perovskite main precursor triggered by DBF is measured by using laser scanning confocal microscopy. It is demonstrated that the addition of DBF in perovskite samples resulted in a deceleration of the crystallization process, which is due to the formation of Lewis acid-base complexes between DBF π-π stacked dimer and perovskite, which can obtain perovskite films with reduced defect density. As a result, the champion PCE of the wide-bandgap (1.68 eV) perovskite device reaches 20.18 %, significantly higher than the control device (17.79 %). Additionally, the device with no encapsulation demonstrates better stability, as it maintains over 90 % of the initial PCE under an air environment with 30–40 % relative humidity (RH) and 25 °C for 1200 h.

Computational screening of PCP-type pincer ligands for Mo-catalyzed nitrogen fixation

Abstract Computational screening of N-heterocyclic carbene-based PCP-type pincer ligands (PCP = 1,3-bis(di-tert-buthylphosphinomethyl)benzimidazole-2-ylidene) has been performed for the design of molybdenum-based molecular catalysts for nitrogen fixation. Previously, we theoretically and experimentally demonstrated that the introduction of electron-donating/withdrawing substituents to the original PCP ligand is a promising way to control the catalytic activity. Here, we investigate electronic and energetic properties of nitrogenous Mo intermediates bearing 40 substituted PCP ligands [MoI(NHx)(R-PCP)] (x = 1 to 3) that are involved in the rate-determining step in our proposed catalytic mechanism. Electron-withdrawing substituents enhance the π-accepting ability of R-PCP and effectively stabilize the lowest unoccupied molecular orbital (LUMO) of the corresponding Mo–nitride (Mo≡N) complexes, which is expected to be advantageous for the transformation of the nitride N atom via proton-coupled electron transfer. The introduction of strong electron-withdrawing substituents to the PCP ligand also increases the N–H bond energy of [MoI(NHx)(R-PCP)] evaluated using the bond dissociation free energy and the bond dissociation enthalpy. As a result of the computational screening, we newly propose an alternative strategy for designing PCP ligands with high π-accepting ability: the extension of the π-conjugated system of the PCP ligand by introducing fused benzene rings.

Constructing π-π Superposition Effect of Tetralithium Naphthalenetetracarboxylate with Electron Delocalization for Robust Dual-ion Batteries.

Organics are gaining significance as electrode materials due to their merits of multi-electron reaction sites, flexible rearrangeable structures and redox reversibility. However, organics encounter finite electronic conductivity and inferior durability especially in organic electrolytes. To circumvent above barriers, we propose a novel design strategy, constructing conductive network structures with extended π-π superposition effect by manipulating intermolecular interaction. Tetralithium 1,4,5,8-naphthalenetetracarboxylate (LNTC) interwoven by carbon nanotubes (CNTs) forms LNTC@CNTs composite firstly for Li-ion storage, where multiple conjugated carboxyls contribute sufficient Li-ion storage sites, the unique network feature enables electrolyte and charge mobility conveniently combining electron delocalization in π-conjugated system, and the enhanced π-π superposition effect between LNTC and CNTs endows laudable structural robustness. Accordingly, LNTC@CNTs maintain an excellent Li-ion storage capacity retention of 96.4% after 400 cycles. Electrochemical experiments and theoretical simulations elucidate the fast reaction kinetics and reversible Li-ion storage stability owing to the electron delocalization and π-π superposition effect, while conjugated carboxyls are reversibly rearranged into enolates during charging/discharging. Consequently, a dual-ion battery combining this composite anode and expanded graphite cathode exhibits a peak specific capacity of 122 mAh g-1 and long cycling life with a capacity retention of 84.2% after 900 cycles.

Self-assembled Quinacridone (QA) based polymers with strong hydrogen bonding for OFETs

For totally disordered organic polymer films, charge mobility is low, while the mobility significantly increases if the polymer exhibits self-assembling properties that can be exploited to generate ordered structures. Introducing a hydrogen-bonding functionality in the materials, resulting in hydrogen-bonded material superstructures, can be a suitable method to fulfil those critical requirements. To the best of our knowledge, the chromophores with hydrogen bonding ability are rarely investigated. Quinacridone (QA) with large π-conjugation system, planar structure as well as the amide and carbonyl groups, is attracted our attention. The hydrogen bonding association (NH…OC) can be formed between the amide groups and the carbonyl units from the QA core. In this work, the QA chromophore is, for the first time, introduced as the electron withdrawing unit in donor-acceptor type polymers for semiconductors. The hydrogen bonded polymers exhibit significantly large red shifted up to 192 nm, which indicates that the hydrogen bonding association in the QA system is powerful. In addition, the hydrogen bonding association led to the polymers not only from a disorder state and inferior crystallinity transferring into a more ordered structures with a block- or fiber-liked-shaped crystalline, but also a strong aggregation. This observation is beneficial for the hole transporting between the neighboring molecules. In addition, the HOMO energy levels have been improved after the hydrogen bonding association formation, which is advantage for the Ohmic contact formation. As a consequent, the hole transport mobility is significantly improved from 0.13 cm2 V−1 s−1–1.02 cm2 V−1 s−1. This work demonstrate that QA is a novel and promising electron-deficient building block with potential strong hydrogen bonding association for the high-performance semiconductor.

A potential building block for spintronic devices: Theoretical description of electronic transport and magnetoresistance of catechol under an external magnetic field stimulus

Understanding the electronic transport properties of low-dimensional devices has increased dramatically in recent decades, especially for those with a promising future for application in nanotechnology. Among these nanoscopic systems are molecular systems, particularly organic molecules such as catechol, representing the small piece of a potential conductor assembled through larger biomolecules and inserted between two or more metal contacts. In this work, we present a theoretical description of the electronic transport of catechol, based on its π-conjugated aromatic system, under an external magnetic field stimulus, which is transverse to the alignment of the molecule. Thus, we analyze catechol’s spintronic properties through the magnetoresistance generated by this field. We model the molecule using a tight-binding Hamiltonian and Green’s functions; the transmission probability is calculated by means of the Fisher-Lee relation, and the characteristic current–voltage, spin polarization, and magnetoresistance curves based on Landauer’s approach for two linking models of catechol to the metallic contacts. The results suggest a strong dependence on the spin direction of the charge carriers and the Zeeman energy (Ez) on the Fermi level, generating a switch-like mechanism going from conducting to semiconducting material. This behavior opens a potential application of these catechol-based systems in future spintronic devices.

Boron-Nitrogen-Embedded Polycyclic Aromatic Hydrocarbon-Based Controllable Hierarchical Self-Assemblies through Synergistic Cation-π and C-H···π Interactions for Bifunctional Photo- and Electro-Catalysis.

Boron-Nitrogen-embedded polycyclic aromatic hydrocarbons (BN-PAHs) as novel π-conjugated systems have attracted immense attention owing to their superior optoelectronic properties. However, constructing long-range ordered supramolecular assemblies based on BN-PAHs remains conspicuously scarce, primarily attributed to the constraints arising from coordinating multiple noncovalent interactions and the intrinsic characteristics of BN-PAHs, which hinder precise control over delicate self-assembly processes. Herein, we achieve the successful formation of BN-PAH-based controllable hierarchical assemblies through synergistically leveraged cation-π and C-H···π interactions. By carefully adjusting the solvent conditions in two progressive assembly hierarchies, the one-dimensional (1D) supramolecular assemblies with "rigid yet flexible" assembled units are first formed by cation-π interactions, and then they can be gradually fused into two-dimensional (2D) structures under specific C-H···π interactions, thus realizing the precise control of the transformation process from BN-PAH-based 1D primary structures to 2D higher-order assemblies. The resulting 2D-BNSA, characterized by enhanced electrical conductivity and ordered 2D layered structure, provides anchoring and dispersion sites for loading two appropriate nanocatalysts, thus facilitating the efficient photocatalytic CO2 reduction (with a remarkable CH4 evolution rate of 938.7 μmol g-1 h-1) and electrocatalytic acetylene semihydrogenation (reaching a Faradaic efficiency for ethylene up to 98.5%).

Tris-Azo Triangular Paraphenylenes: Synthesis and Reversible Interconversion into Radial π-Conjugated Macrocycles.

We report the synthesis of cycloparaphenylene derivatives featuring tris-azo groups. The smaller derivative, [3]cycloazobenzene, adopts a triangular all-cis form and exhibits thermally and photochemically stable characteristics due to significant ring strain as well as symmetric Kagome-patterned crystal packing. In contrast, the as-synthesized [3]cycloazobenzene with three biphenylene bridges adopts a triangular all-cis form, which undergoes photoinduced isomerization, leading to a photostationary state. Interestingly, the addition of an excess of acid selectively leads to the formation of an all-trans form. DFT calculations reveal that the interconversion from a triangular to a circular shape correlates with an increase in HOMO and a decrease in LUMO, characteristics intrinsic to radial π-conjugated systems.

Computational analysis of ligand design for Ru half-sandwich sensitizers in bulk heterojunction (BHJ) solar cells: Exploring the role of –NO2 group position and π-conjugation in optimizing efficiency

Bulk Heterojunction (BHJ) solar cells offer cost-effective photovoltaic solutions, flexible manufacturing, and improved efficiency with reduced environmental impact. Organometallic half-sandwich complexes, specifically a series of monometallic ruthenium complexes (Ru(1)–Ru(6)), have emerged as promising candidates for BHJ solar cells due to their outstanding charge transport properties. This study utilised Density Functional Theory (DFT) calculations with the B3LYP functional and SDD basis set augmented with 6-31 + G(d,p) to assess these Ru complexes with various N,O-chelating ligands, featuring distinct π-conjugated systems and positions of nitro groups, for BHJ solar cell applications. Our investigation focused on elucidating their electronic structures, identifying key electrophilic and nucleophilic sites, and exploring their optical properties. Our findings indicate that these complexes have maximum absorption wavelengths (λmax) ranging from 702 to 1083 nm, highlighting their strong photon absorption capabilities. Specifically, Ru(6), which includes the NO2 group, exhibits the narrowest energy gap but shows relatively lower values for oscillator strengths (f) and light harvesting efficiencies (LHE), indicating efficient light absorption but reduced energy conversion efficiency. In contrast, Ru(3), lacking the NO2 group but featuring enhanced π conjugation through cyclisation, demonstrates the widest energy gap yet boasts the highest values for f and LHE, suggesting superior efficiency in converting absorbed energy into electronic energy. These results emphasise the crucial role of ligand π-conjugation in enhancing energy conversion efficiency, while the strategic positioning of the NO2 group aids effective light absorption. Our study offers valuable insights into the design principles for optimizing organometallic ruthenium complexes in BHJ solar cell applications.

Highly efficient multi-resonance thermally activated delayed fluorescence material toward a BT.2020 deep-blue emitter

An ultrapure deep-blue multi-resonance-induced thermally activated delayed fluorescence material (DOB2-DABNA-A) is designed and synthesized. Benefiting from a fully resonating extended helical π-conjugated system, this compound has a small ΔEST value of 3.6 meV and sufficient spin–orbit coupling to exhibit a high-rate constant for reverse intersystem crossing (kRISC = 1.1 × 106 s–1). Furthermore, an organic light-emitting diode employing DOB2-DABNA-A as an emitter is fabricated; it exhibits ultrapure deep-blue emission at 452 nm with a small full width at half maximum of 24 nm, corresponding to Commission Internationale de l’Éclairage (CIE) coordinates of (0.145, 0.049). The high kRISC value reduces the efficiency roll-off, resulting in a high external quantum efficiency (EQE) of 21.6% at 1000 cd m–2.

A ratiometric fluorescence probe for bisulfite detection in live cells and meat samples

The development of reliable probe technology for the detection of bisulfite (HSO3-) in situ in food and biological samples is contributing significantly to food quality and safety assurance as well as community health. In this work, a responsive probe, EHDI, is developed for ratiometric fluorescence detection of HSO3- in aqueous solution, meat samples, and living cells. The probe is designed based on the HSO3- triggered 1,4-addition of electron deficit C = C bond of EHDI. As a result of this specific 1,4-addition, the π-conjugation system was destructed, resulting in blue shifts of the emission from 687 to 440 nm and absorption from 577 to 355 nm. The probe has good water solubility, high sensitivity and selectivity, allowing it to be used for imaging of HSO3- internalization and production endogenously. The capability of probe EHDI for HSO3- was then validated by traditional HPLC technology, enabling accurately detect HSO3- in beef samples. The successful development of this probe thus offers a new tool for investigating HSO3- in situ in food and biological conditions.

Synthesis, Characterization of New Benzopyran Pyrimidines and Study of their Solvatochromic Behaviour

Five new benzopyran pyrimidines (5a-e) were synthesized in three steps by using silica-sulphuric acid as catalyst. All the synthesized benzopyran pyrimidines with various substituents were characterized by spectroscopic techniques such as 1H NMR, 13C NMR, IR and mass spectroscopy. The structural features of these molecules containing pyrimidine ring with π-conjugated systems and various functional groups on the aromatic rings greatly influence their photophysical properties. Thus, they behave as better candidates for developing the photoelectric materials. Thus, it is proposed to synthesize, characterize and study their solvatochromic behaviour in various polar and non-polar organic solvents viz. dichloromethane, tetrahydrofuran, ethyl acetate, acetonitile and ethanol. Interestingly, all the target molecules exhibited greater Stoke’s shift (λf-λa) in dichloromethane except for compound 5e, which exhibited greater value in tetrahydrofuran, possibly due to the moderately polar nature of the solvent. The synthesized benzopyran pyrimidines displayed solvatochromic characteristics due to the presence of multiple substituted functional groups on the rings in different organic solvents. Due to their remarkable properties, they could serve as potential candidate molecules for future investigations into photoelectric materials.

Hybrid HMX multi-level assembled under the constraint of 2D materials with efficiently reduced sensitivity and optimized thermal stability

The interfacial interaction between HMX molecules and coating materials is the key to the safety performance of explosives and has received extensive attention. However, screening suitable coating agents to enhance the interfacial effect to obtain high-energy and low-sensitivity explosives has long been a major challenge. In this work, HMX-PEI/rGO/g-C3N4 (HPrGC) composites were innovatively prepared by a multi-level coating strategy of two-dimensional graphite rGO and g-C3N4. The g-C3N4 used for desensitization has a rich π-conjugated system and shows outstanding ability in reducing friction sensitivity. The hierarchical structure of HPrGC formed by electrostatic self-assembly and π-π stacking can effectively dissipate energy accumulation under heat and mechanical stimulation through structural evolution, thus exhibiting a prominent synergistic desensitization effect on HMX. The results show that rGO/g-C3N4 coating has no effect on the crystal structure and chemical structure of HMX. More importantly, the perfect combination of g-C3N4 and rGO endows HPrGC with enhanced thermal stability and ideal mechanical sensitivity (IS: 21 J, FS: 216 N). Obviously, the new fabrication of HPrGC enriches the variety of desensitizer materials and helps to deepen the understanding of the interaction between explosives and coatings.

Synthesis and evaluation of modified polyhedral oligomeric silsesquioxane (POSS) derivatives with luminescent Side-chains having charge-transfer characters

Abstract We describe here a synthesis and evaluation of polyhedral oligomeric silsesquioxane (POSS) derivatives having luminescent charge-transfer molecules. The electron withdrawing groups (EWG), such as trifluoromethyl groups, and electron donating groups (EDG), such as methoxy and dimethylamine groups, were introduced into π-conjugated systems connected at each vertex of the silica cube, and their optical properties were evaluated in solution and solid states. It was shown that the POSS scaffold hardly influenced the electronic structures of each substituent, meanwhile there were significant differences in electronic interactions between EWGs and EDGs depending on the order of connections from the silica cube. Finally, we obtained heat resistant luminescent materials having intermolecular charge-transfer characteristics.

Few-Layer Meets Crystalline Structure: Collaborative Efforts for Improving Photocatalytic H2O2 Generation over Carbon Nitride.

Although the conversion of O2 and H2O to H2O2 over graphite carbon nitride (g-C3N4) has been realized by means of the photocatalytic process, the catalytic activity of pristine g-C3N4 is still restricted by the rapid charge recombination and inadequate exposure of the active site. In this work, we propose a straightforward strategy to solve these limitations by decreasing the thickness and improving the crystallinity of g-C3N4, resulting in the preparation of few-layered crystalline carbon nitride (FL-CCN). Benefiting from the minimal thickness and highly ordered in-plane triangular cavities within the structure, FL-CCN processes an extended π-conjugated system with a reduced charge transfer resistance and expanded specific surface area. These features accelerate the efficiency of photogenerated charge separation in FL-CCN and contribute to explore of its surface active sites. Consequently, FL-CCN exhibits a significantly improved H2O2 evolution rate (63.95 μmol g-1 h-1), which is 7.8 times higher than that of pristine g-C3N4 (8.15 μmol g-1 h-1), during the photocatalytic conversion of O2 and H2O. This systematic investigation offers valuable insights into the mechanism of photocatalytic H2O2 generation and the development of efficient catalysts.

Polymer Microspheres Copolymerized with Deep Red Fluorescent Molecules as a Label for Lateral Flow Immunochromatography.

The development of fluorescently labeled microspheres is a critical aspect of advancing the technology of lateral flow immunochromatography (LFIA) for biological detection. Nevertheless, potential interference posed by the background fluorescence originating from the nitrocellulose (NC) membrane would significantly impact the sensitivity and accuracy of microsphere-based detection in LFIA. In this work, an attempt was made to extend the π-conjugated system and asymmetric structure of rhodamine fluorophore, resulting in the synthesis of dye molecules (RB2) incorporating double bonds, which can reach an absolute photoluminescence quantum yield (PLQY) of 30.01% in EtOH. Subsequently, carboxyl group functionalized fluorescent microspheres were prepared in a two-step copolymerization via soap-free emulsion polymerization. The obtained microspheres were characterized by scanning electron microscopy, transmission electron microscopy, DLS, Fourier transform infrared spectroscopy, ultraviolet spectrophotometry, and fluorescence spectrophotometry. The results showed that RB2 was successfully copolymerized into the microspheres, and the resulting microspheres had good dispersion and stability with high red fluorescence intensity (λabs ∼ 610 nm, λem ∼ 660 nm). Utilizing these microspheres, the resulting lateral flow immunoassay was successfully found to detect SARS-CoV-2 N protein with a detection limit of 2.5 pg/mL and the linear concentration spanning from 2.5 pg/mL to 10 ng/mL. The results confirm the effectiveness of the synthetic fluorescent microspheres as the label for LFIA.

Extended Conjugation Strategy Enabling Red-Shifted and Efficient Emission of Orange-Red Thermally Activated Delayed Fluorescence Materials.

In account of the energy gap law, the development of efficient narrow-band gap thermally activated delayed fluorescence (TADF) materials remains a major challenge for the application of organic light-emitting diodes (OLEDs). The orange-red TADF materials are commonly designed with either large π-conjugated systems or strong intramolecular donor-acceptor (D-A) interactions for red-shift emission and small singlet-triplet energy gap (ΔEST). There are rare reports on the simultaneous incorporation of these two strategies on the same material systems. Herein, two orange-red emitters named 1P2D-BP and 2P2D-DQ have been designed by extending the conjugation degree of the center acceptor DQ and increasing the number distribution of the peripheral donor PXZ units, respectively. The emission peak of 1P2D-BP is red-shifted to 615 nm compared to 580 nm for 2P2D-DQ, revealing the pronounced effect of the conjugation extension on the emission band gap. In addition, the distorted molecular structure yields a small ΔEST of 0.02 eV, favoring the acquisition of a high exciton utilization through an efficient reverse intersystem crossing process. As a result, orange-red OLEDs with both 1P2D-BP and 2P2D-DQ have achieved an external quantum efficiency (EQE) of more than 17%. In addition, the efficient white OLED based on 1P2D-BP is realized through precise exciton assignment and energy transport modulation, showing an EQE of 23.6% and a color rendering index of 82. The present work provides an important reference for the design of high-efficiency narrow-band gap materials in the field of solid-state lighting.