Themed collection 20th Anniversary of Aggregation-Induced Emission

Fengyan Song, Bin Liu and Ben Zhong Tang introduce the celebration of the 20th anniversary of aggregation-induced emission with research highlights from Royal Society of Chemistry journals.

Purely organic materials showing solid state room temperature phosphorescence (RTP) are receiving an ever growing interest due to their low toxicity, cost and environmental load compared to their organometallic counterparts.

A Y-shape and pyrene-modified DNA self-assembly is developed to sensitively and specifically detect microRNA through a pyrene excimer–monomer switch.

We report a luminescent micelle that is prepared through the self-assembly of an amphiphilic, neutral Pt(II) complex with isoxazole moieties in THF/water on account of its aggregation-induced emission (AIE) property.

Polyacrylonitrile (PAN) brushes were grafted from silicon wafers by photoinduced ATRP and shown to exhibit aggregation-induced emission (AIE) properties.

Dual-targeted organic nanoparticles efficiently target the margin of glioblastoma and successfully suppress the tumour growth through photothermal therapy.

We herein present a simple methodology to systematically expand the scope of maleimide-based dyes and also provide an insight into the relationship between substitution pattern and optical properties.

A novel fluorescent cassette consisting of a TPE donor and a cyanine acceptor was developed for sensitive detection of pH changes in live cells.

Trigonal fluorinated pyrazoles assemble into porous molecular crystals and show solid-state fluorescence. However, their emission behavior in solution is dramatically different.

Molecular siblings 1 and 2 are constructed from triarylboron and phenothiazine moieties and showed multifunctional characteristics such as AIE, mechanofluorochromism, triboluminescence and temperature sensing.

Two crystalline polymorphs of TMPE (C_p-form and C_c-form) exhibit totally different mechanoluminescence properties.

Aggregation-induced emission and delayed fluorescence are observed simultaneously for the luminogens with an electron-donor and acceptor framework.

We report a multifunctional light-up probe based on AIEgens for selective recognition, naked-eye identification, and photodynamic killing of Gram-positive bacteria including vancomycin-resistant strains.

THz-TDS and computational modelling reveal temperature dependent structural changes that correlate with fluorescence.

A simple synthesis strategy for highly luminescent thiolated Au@Ag nanoclusters with aggregation-induced emission was developed.

Aggregation induced emission in diphenyl dibenzofulvene occurs because access to a conical intersection seam is blocked in the solid state.

Difluorenylidene dihydroanthracene with a butterfly-like structure exhibits both aggregation induced emission (AIE) and thermally activated ground-state spin switching properties.

This article presents the first work to fundamentally study the effect of steric hindrance in Pdot systems.

Complex arrangements of tetraphenylethylene motifs resulted in a variety of chiralities of face-rotating sandwich structures (FRSs).

Findings on the structure and formation of luminescent protein-stabilized gold clusters reveal interlocked gold-thiolate rings and a unique bio-assembled pathway.

A mitochondrion-specific AIEgen is a theranostic molecule, with the function of lighting up and killing cancer cells rather than normal cells.

The efficiency of the intersystem crossing process can be improved by reducing the energy gap between the singlet and triplet excited states (ΔE_ST), which offers the opportunity to improve the yield of the triplet excited state.

A CF₃-BODIPY forms strongly luminescent aggregates, which contrasts with the quenched condensed-phase photophysics that are typical for BODIPY dyes. Examination of the luminescent properties of these aggregates – narrow red-shifted absorption and emission bands, minimal Stokes shift and increased fluorescence rate constants – and of the solid-state packing of the dye establish the CF₃-BODIPY as the first structurally characterized genuine BODIPY J-aggregate.

A newly designed molecular system shows high CPL performance in the aggregate state: high emission efficiency, large dissymmetry factor, and good spectral stability.

A new organometallic alkynyl–gold(I) complex exhibiting aggregation induced emission is capable of sensing Guanosine nucleotides via complementary hydrogen bonding in aqueous media.

Light scattering and absorption both contribute to the UV-vis extinction quantified with a UV-vis spectrophotometer, but they differ drastically in their causes and effects.

A neutral Ir(III) complex has been synthesized by introducing a carboxyl group and fluorine substituents into the ligands to construct a new piezochromic luminescence (PCL) active material.

Blue multi-functional emitters with a perfluorobiphenyl moiety exhibiting polymorphism and changing emission colour.

A Co(II) complex based on an AIE-active tetraarylethylene ligand displays selective fluorescence enhancement in the presence of cyanide anion in aqueous solution.

Nonconventional poly(maleic anhydride-alt-vinyl pyrrolidone) copolymers exhibit distinct AIE characteristics, as well as molecular weight-dependent and excitation-dependent fluorescence. They can emit blue to red colours under different excitation wavelengths.

The molecular origin of the photoluminescence of carbon dots (CDs) is shown.

Bis(piperidyl)anthracenes were developed as structurally simple, bright and colour tuneable AIE luminogens and their emission mechanisms were analysed.

A dual-emission ratiometric fluorescent sensor based on AIE organic nanoparticles and Au NCs was prepared by electrostatic interaction. The probe can detect Hg²⁺ and melamine not only visually but quantitatively.

Halide-substituted difluoroboron β-diketonates were synthesized and display mechanochromic luminescence and quenching. Material structure is halide dependent and dynamic recovery properties for halide dyes are slower than for the hydrogen counterpart.

The hexathio-benzene core molecule (right) shows outstanding phosphorescence as a powder (left) and has been used for luminescent organic nanocrystals and OLED.

Circular dichroism behavior was regulated by controlling the molecular conformation of BINOL derivatives, and tunable solid-state circularly polarized luminescence was achieved.

An o-phthalimide-based AIE system was developed and used for detecting UV light, Hg(II) and pH, and as a photo-printing material.

Two dyes showing aggregation induced emission behaviour were examined for use as a light harvesting Förster resonance energy transfer pair in luminescent solar concentrators.

The control of luminescence properties between fluorescence aggregation-caused quenching and aggregation-induced emission with or without a chemical bond at a single site in boron complexes was accomplished.

Non-substituted and alkyl-substituted triphenylamine–dibenzo[a,c]phenazine adducts (Q1–Q3) showed the combined features of ICT plus AEE, while the alkoxy-substituted Q4–Q5 exhibited obvious AIE effects.

Changing the heteroatom from oxygen to sulfur in a luminescent difluoroboron β-diketonate converts a thermally responsive material into a mechano responsive dye system.