Anti-Kasha triplet energy transfer and excitation wavelength dependent persistent luminescence from host-guest doping systems.

Anti-Kasha's process in organic luminogens has attracted many attentions since its discovery. However, only limited examples of anti-Kasha's rule have been reported and anti-Kasha triplet energy transfer (ET) is even less-touched. Benefiting from anti-Kasha's rule, this work provided an efficient strategy to realize excitation wavelength dependent (Ex-De) afterglow in a host-guest system.

Two Cholesterol-Containing Pyrene Derivatives: Subtle Spacer Difference, Diverse Stimuli-Responsive Luminescence, Chirality, and Self-Assembly Behaviors.

Two chiral molecules and were designed and synthesized with a pyrene moiety directly linked to a chiral cholesterol moiety and connected through a methylene spacer, respectively. Influence of the spacer on their stimuli-responsive luminescence, chirality, and self-assembly behaviors was systematically investigated. Molecules and had similar aggregation-induced emission enhancement (AIEE) in solution, because of carrying the same fluorescence moiety.

Insight into Isomeric Effect on the Photoluminescence and Mechanoluminescence of Cyanostilbene Derivatives.

Molecular structures, packings, and intermolecular interactions significantly affect the photophysical properties of organic luminogens. In this work, the photoluminescence (PL) and mechanoluminescence (ML) of two pairs of isomers, / and /, were systematically explored. The fluorescence of crystals and is much brighter than that of their isomers and , respectively.

Controllable room temperature phosphorescence, mechanoluminescence and polymorphism of a carbazole derivative.

Room temperature phosphorescence (RTP) and mechanoluminescence (ML) materials are in high demand because of their promising applications in optoelectronic devices. However, most materials bear only one of these properties and molecules bearing both of them are rarely reported. Here, we report a carbazole derivative 1, which displays both RTP activity and near-ultraviolet ML properties.

Direct Visualization of Chiral Amplification of Chiral Aggregation Induced Emission Molecules in Nematic Liquid Crystals.

Chiral amplification in liquid crystals (LCs) is a well-known strategy. However, current knowledge about the underlying mechanism was still lacking; in particular, how it was realized at the nano scale still remained to be revealed. Here, we provide systematical exploration of chiral amplification of chiral aggregation induced emission (AIE) molecules in LCs from direct visualization of their co-assemblies at the nano scale to theoretical calculation of the molecular packing modes on a single molecular level.

Multiple Anti-Counterfeiting Guarantees from a Simple Tetraphenylethylene Derivative - High-Contrasted and Multi-State Mechanochromism and Photochromism.

Herein the novel tetraphenylethylene (TPE) derivative 1 was designed with an integration of aggregation-induced emission (AIE), multi-state mechanochromism and self-recovery photochromism. The molecule was susceptible to grinding, heating and vapor fuming and showed corresponding transition of its emission colors. The heated powder or single crystal of 1 exhibited reversible photochromism.

Big, strong, neutral, twisted, and chiral π acids.

General synthetic access to expanded π-acidic surfaces of variable size, topology, chirality, and π acidity is reported. The availability of π surfaces with these characteristics is essential to develop the functional relevance of anion-π interactions with regard to molecular recognition, translocation, and transformation. The problem is that, with expanded π surfaces, the impact of electron-withdrawing substituents decreases and the high π acidity needed for strong anion-π interactions can be more difficult to obtain.

Achieving exceptionally high luminescence quantum efficiency by immobilizing an AIE molecular chromophore into a metal-organic framework.

We design a new yellow phosphor with high quantum yield by immobilizing a preselected chromophore into a rigid framework. Coating a blue light-emitting diode (LED) with this compound readily generates white light with high luminous efficacy. The new yellow phosphor demonstrates great potential for use in phosphor-converted white LEDs.

Turn-on of the fluorescence of tetra(4-pyridylphenyl)ethylene by the synergistic interactions of mercury(II) cation and hydrogen sulfate anion.

The fluorescence of tetra(4-pyridylphenyl)ethylene (1) can be switched on significantly by the synergistic interactions of Hg(2+) and HSO(4)(-) based on a new aggregation mechanism for tetraphenylethylene molecules.

Dendron-containing tetraphenylethylene compounds: dependence of fluorescence and photocyclization reactivity on the dendron generation.

The synthesis and characterization of four dendron-containing tetraphenylethylenes (TPEs), 1(1)-1(4), were synthesized, along with a TPE compound that contained four OCH(2) Ph groups (referred to as 1(0)) for comparison. Photophysical studies revealed that the TPE core became emissive after linking dendrons onto its periphery. Moreover, the fluorescence intensity was significantly enhanced when high-generation dendrons were linked onto the TPE core; the fluorescence intensity increased in the following order: 1(1)<1(2)<1(3)<1(4).