Researchers from Japan have developed a computational framework to predict luminescence in aggregation-induced emission (AIE) materials, focusing on bridged stilbene derivatives to reveal how donor and acceptor groups control excited-state behavior. The team reports demonstrating that the position of these groups dictates the excited-state potential energy surface and accessibility of conical intersections, key to understanding how AIEgens emit light when aggregated.
“AIE behavior is associated with large structural changes involving substantial reorganization of π-electron systems,” says Associate Professor Gen-ichi Konishi of the Department of Chemical Science and Engineering at Institute of Science Tokyo, Japan; their work offers a rational design strategy for these materials with potential applications in OLEDs, bioimaging, and sensors.
Quantum Calculations Reveal AIE Luminogen Excited-State Surfaces
Low-lying conical intersections, critical for determining how efficiently a molecule emits light, were the focus of a recent computational study of aggregation-induced emission (AIE) luminogens. Researchers successfully linked the accessibility of these intersections to specific molecular features, offering a new pathway for designing brighter, more efficient AIE materials. The team’s work, published in Advanced Science on June 18, 2026, combined quantum chemical calculations with organic synthesis and experimental spectroscopy to map excited-state potential energy surfaces in bridged stilbene derivatives.
The ability to predict AIE behavior has historically relied on empirical trial and error, but the researchers report demonstrating that donor and acceptor groups, and their positions on the molecule, dictate the shape of the excited-state potential energy surface. This control stems from the influence of these groups on conical intersections, which act as energy funnels that can deactivate excited molecules without light emission.
By manipulating these intersections through molecular design, the team aimed to suppress nonradiative decay and enhance luminescence. This new approach differs from previous methods by utilizing a small number of computational descriptors derived from quantum chemical calculations to predict AIE behavior. The team’s success suggests a shift away from random screening towards rational, computation-guided molecular exploration. In solution, structural changes within these molecules can deactivate the excited state, but in the solid state, these processes are suppressed, allowing for light emission; understanding this dynamic requires detailed analysis of the excited-state potential energy surfaces.
This work represents a shift in luminescent material design, moving from empirical trial and error toward rational, computation-guided molecular exploration.
Gen-ichi Konishi, Associate Professor at Department of Chemical Science and Engineering, Institute of Science Tokyo
Donor-Acceptor Positioning Controls Conical Intersection Accessibility
The energetic relationship between a molecule’s initial excited state and conical intersections can be directly manipulated through the placement of donor and acceptor groups, according to analyses of bridged stilbene derivatives. Researchers discovered that these groups alter the excited-state potential energy surface, effectively regulating how easily excited molecules can shed energy without emitting light, a key factor in aggregation-induced emission, or AIE. They revealed how subtle structural changes redirect the flow of energy within the molecule.
Synthesizing four representative bridged stilbenes based on these computational insights confirmed the predictive power of the framework. This is significant because AIEgens, unlike most fluorescent molecules, increase in luminescence when they come together or solidify, a property valuable for applications where solid-state emission is required.
The proposed framework establishes a strategy for controlling excited-state dynamics through molecular structure. We expect it to contribute to the development of high-efficiency OLED materials, fluorescent probes for bioimaging, and sensing materials.
Gen-ichi Konishi, Associate Professor at Department of Chemical Science and Engineering, Institute of Science Tokyo
Bridged Stilbenes Validate Computation-Guided AIE Design
Quantum chemical potential energy surface analyses on 30 stilbene derivatives revealed how bridge size, donor and acceptor substitution, and their positions impacted conical intersection (CI) accessibility, establishing a link between molecular architecture and luminescence behavior. These calculations pinpointed a limited set of energetic descriptors capable of evaluating whether an excited molecule could efficiently reach a CI, streamlining the design process. Ultrafast transient absorption spectroscopy and CI topology analysis confirmed the computational predictions, demonstrating that donor and acceptor group arrangement directly alters CI topology and accessibility.
This control dictates the efficiency of nonradiative deactivation pathways for excited molecules, effectively tuning the material’s emission characteristics. According to Associate Professor Gen-ichi Konishi of the Department of Chemical Science and Engineering at Institute of Science Tokyo, Japan, their work provides a rational strategy for exploring and designing luminescent AIE materials for applications such as OLEDs, bioimaging, and sensors.
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