Methyl-restricted rotor rotation on the stator produces high-efficiency fluorescence emission: a new strategy to achieve aggregation-induced emission

At present, we have realized that the aggregation-induced emission (AIE) achieves the purpose of fluorescence enhancement by restricting rotations to reduce intermolecular or intramolecular energy loss. Based on this idea, we synthesized a novel fluorene-based fluorescent compound with a restricted rotor rotation on the stator through the Suzuki coupling reaction. The luminescence effect was evaluated by comparing its fluorescence intensity with that of the control compound. Finally, theoretical calculations showed that the presence of methyl groups hindered the thermal rotation of the fluorenyl groups. Thus, the results indicated that the fluorescence of this compound was better than that of the control compound. A new synthetic pathway for high-efficiency AIE-based fluorescent luminogens has been developed.

At present, we have realized that the aggregation-induced emission (AIE) achieves the purpose of fluorescence enhancement by restricting rotations to reduce intermolecular or intramolecular energy loss.

Tailoring the photoluminescence of atomically precise nanoclusters

Due to their atomically precise structures and intriguing chemical/physical properties, metal nanoclusters are an emerging class of modular nanomaterials. Photo-luminescence (PL) is one of their most fascinating properties, due to the plethora of promising PL-based applications, such as chemical sensing, bio-imaging, cell labeling, phototherapy, drug delivery, and so on. However, the PL of most current nanoclusters is still unsatisfactory-the PL quantum yield (QY) is relatively low (generally lower than 20%), the emission lifetimes are generally in the nanosecond range, and the emitted color is always red (emission wavelengths of above 630 nm). To address these shortcomings, several strategies have been adopted, and are reviewed herein: capped-ligand engineering, metallic kernel alloying, aggregation-induced emission, self-assembly of nanocluster building blocks into cluster-based networks, and adjustments on external environment factors. We further review promising applications of these fluorescent nanoclusters, with particular focus on their potential to impact the fields of chemical sensing, bio-imaging, and bio-labeling. Finally, scope for improvements and future perspectives of these novel nanomaterials are highlighted as well. Our intended audience is the broader scientific community interested in the fluorescence of metal nanoclusters, and our review hopefully opens up new horizons for these scientists to manipulate PL properties of nanoclusters. This review is based on publications available up to December 2018.

Environment dependent photophysical and fluorescence turn-off sensing properties of Fe(iii) by substituted phenyl isochromenopyrrol-5-ones

The proposed isochromenopyrrolones can serve as highly selective and sensitive sensors for iron(iii) in pharmaceutical, industrial and biological applications.

Photophysical investigation of two emissive nucleosides exhibiting gigantic stokes shifts

We present discovery of two highly emissive nucleoside analogs with gigantic Stokes shifts and use in silico methods for rationalizing their striking fluorescent properties.

Two-isophorone fluorophore-based design of a ratiometric fluorescent probe and its application in the sensing of biothiols

A newly designed ratiometric fluorescent probe is applied in the sensing of biothiols.