Xin Jin

Polycyclic aromatic hydrocarbons with large conjugated planes and low reorganization energy serve as an ideal molecular platform for organic semiconductors; however, precisely controlling their aggregated structures to achieve large transfer integrals and thus excellent charge transport efficiency remains a significant challenge. Herein, we design and synthesize a sila‐annulated hexarylene diimide ( 2Si‐HDI ) featuring imide units at both peri ‐positions and two silole rings at the central bay ‐positions. Through the quadruple C─H···(O═C) locking between carbonyls of the diimide groups and the hydrogen atoms of the 1,1'‐diethylsilyl groups at the silole rings, we realized the first 1D slipped π – π stacking of ultra‐long rylenes (naphthalene unit ≥ 6), providing groundbreaking guidance for the well‐ordered π – π self‐assembly of large planar PAHs relevant to armchair graphene nanoribbons. The single‐crystalline organic field‐effect transistor properties of 2Si‐HDI exhibit hole/electron mobilities up to 3.08/0.06 cm ² V ⁻¹ s ⁻¹ . Theoretical calculations reveal hole/electron transfer integrals of 2Si‐HDI as high as 110.08/78.08 meV along the π – π stacking direction, rationalizing its superior charge transport performance.

Restricted by low isomerization barriers, many dynamically chiral molecules often remain racemic, which has hindered their application in chiral functional materials. This work reports a synergistic strategy combining steric methylation with macrocyclization to transform dynamic into static chirality. The macrocycle P5P21 was synthesized by embedding the dynamic unit DPP21 into a pillararene. Structural analyses revealed that the pronounced spatial confinement imposed by the pillararene effectively froze the conformational inversion of DPP21 , enabling significant chiroptical activity induced by a single methyl group. This strategy dramatically enhanced emission color purity, narrowing the photoluminescence full width at half maximum (FWHM) from 107 to 41 nm, and boosted the quantum yield (PLQY) from 13.1% to 42.7%, yielding efficient narrowband emission in the near‐ultraviolet region (371 nm). Mechanistically, macrocyclic locking not only raised the configurational inversion barrier from 17 kcal/mol to >21 kcal/mol, ensuring conformational stability, but also significantly reduced the excited‐state reorganization energy, which is key to narrowband emission. This study provides a versatile design paradigm for stable, efficient chiral luminescent materials.

This review provides an overview of vibration-induced emission (VIE), a new approach that allows molecules to emit multiple colors by undergoing conformational changes. The focus is on sterically hindered dihydrophenazine (DHP) derivatives, especially the N,N′-diphenyl-dihydrodibenzo[a,c]phenazine (DPAC) core, illustrating how large-amplitude “butterfly” vibrational motions in the excited state govern their light emission behavior. Key molecular design strategies for VIE-active compounds are highlighted, revealing how the interplay of steric hindrance and electronic properties modulates excited-state energies and facilitates color tuning from blue to red, including the realization of intrinsic triple fluorescence. Advanced spectroscopy and theoretical studies are employed to explore the link between molecular conformation and emission properties. Additionally, innovative applications of VIE systems are discussed, especially in molecular cursor calipers for differential sensing, and microenvironment-responsive probes corresponding to different matrices. This review aims to stimulate broad interest across diverse fields, expanding both the scope of VIE research and the development of advanced functional materials.

A selective, efficient intramolecular amination strategy yields dihydrophenazine derivatives with distinct heteroatom doping. These structures modulate excited-state dynamics, making them promising for high-performance OLEDs.

Smart molecules possess the ability to perceive and respond to external stimuli. However, most currently existing smart molecules only showcase simple binary responses to individual stimuli. To enhance molecular stimulus‐responsiveness, we developed a dynamic molecule, 5,10‐bis(dimesitylboryl)‐5,10‐dihydrophenazine ( BNNB ). This molecule integrates two dynamic units: dihydrophenazine with adjustable aromaticity and BN bonds with tunable bonding order, enabling greater versatility. BNNB undergoes three‐stage conformational changes through the mono‐ or di‐twisting of the BN bonds and the planarization of the dihydrophenazine, demonstrating conformation‐driven multilevel responsiveness to multiple stimuli. The dynamic modification of molecular conformations leads to pronounced changes in absorption and fluorescence, resulting in noticeable thermochromism , mechanochromism , and electrochromism , as well as exhibiting force‐induced thermally activated delayed fluorescence and triple fluorescence emission arising from photoisomerization . These findings establish an integrated approach to achieving multi‐stimulus and multi‐level responses, paving the way for the development of multifunctional and multimodal responsive systems based on single‐molecule designs.

L-glufosinate has garnered increasing attention as an ideal herbicide for weed control in agriculture. However, the underlying racemization process of l-glufosinate in the aqueous phase remains unclear. In this work, we elucidated the racemization mechanisms through heating reactions and theoretical calculations. Results showed that temperature has a significant impact on the racemization of l-glufosinate. The higher the temperature, the faster racemization occurs, which follows first-order kinetics. Moreover, it is evident that water plays an important role in the racemization process of l-glufosinate, as demonstrated by the heating of crystals and deuterium experiments. Additional computational results suggested a dual-step transformation, with a decrease in the energy barrier of about 29.25 kcal/mol for racemization attributed to the participation of water molecules, thereby promoting the racemization process. This work offers valuable insights into the important mechanistic and kinetic features of these reactions through the combination of experiments and theoretical calculations, guiding the chiral control of l-glufosinate in industrial production.

Type I photodynamic therapy is considered to be a more promising cancer treatment than type II photodynamic therapy due to its non-oxygen-dependent characteristics. In this work, three D–A structure N,N′-dihydrophenazine (DHP)-based photosensitizers DP-CNPY, SMP-CNPY and DMP-CNPY were designed and synthesized by introducing different numbers of methyl groups in the backbone neighbor of DHP as the donor and combined with the typical strong electron acceptor 2-(pyridin-4-yl)acetonitrile. Among the three photosensitizers, SMP-CNPY with one methyl modification showed the best type I ROS (O₂ ⁻˙, ˙OH) generation capacity and AIE performance. By encapsulation, SMP-CNPY was fabricated into nanoparticles, and SMP-CNPY NPs exhibited lipid droplet targeting ability with near-infrared (NIR) emission. Cell experiments have proved that SMP-CNPY NPs can effectively kill different kinds of cancer cells under normal oxygen conditions. Even under hypoxic and extreme hypoxic conditions, SMP-CNPY NPs can still produce ROS and kill cancer cells. This work holds significant potential in the field of type I AIE-active photosensitizers and provides a new strategy for overcoming the hypoxic dilemma in the malignant tumor microenvironment.

Developing luminogens with a high emission efficiency in both single-molecule and aggregate states, as well as high mobility, shows promise for advancing the iteration and update of organic optoelectronic materials. However, achieving a delicate balance between the plane configuration of luminophores and the strong exciton interactions of aggregates is a formidable task from the molecular design perspective. This dilemma was overcome by integrating a rigid donor and flexible acceptor to establish donor-acceptor (D-A) type emitters. The pi-conjugate-extended donor ensures the substantial planarity of these molecules, allowing strong emission in solution with photoluminescence quantum yield values of 86% and 75%. Furthermore, the restricted molecular motion of the aggregation-induced emission moiety and the formation of J-aggregates reduce the quenching effect, leading to a high emissive efficiency of 85% and 91% in the aggregate state. The mildly distorted D-A geometry builds moderate electrostatic interaction, resulting in high mobility with mu M,h of 7.12 x 10(-5) and 3.27 x 10(-4) cm(2)/V s. Additionally, an improved synthesized procedure for terminal E-configured acrylonitrile with metal-free and concise reaction conditions is presented. The successful application of the synthesized compounds in organic light-emitting diode devices demonstrates the practicability of the molecular design strategy with connecting a rigid donor and flexible acceptor.