1,8-Naphthalimide-Based Highly Emissive Luminophors with Various Mechanofluorochromism and Aggregation-Induced Characteristics

Abstract

Six 1,8-naphthalimide-based tetraphenylethene derivatives were reported. These highly solid-state emissive compounds showed aggregation-induced emission enhancement or aggregate fluorescence change characteristics. Furthermore, these aggregation-induced green light-emitting or aggregation-induced yellow light-emitting luminophors also exhibited various mechanofluorochromism behaviors involving different fluorescent color changes. To determine the mechanochromic mechanism of these six mechanical stimulus-responsive luminogens, the powder X-ray diffraction (XRD) and X-ray single-crystal measurements were carried out. The powder XRD test results indicated that their interesting mechanofluorochromic behaviors were attributed to the interconversion between crystalline and amorphous states. Meanwhile, the X-ray single-crystal analyses results implied that the twisted molecular conformation and the absence of an intense intermolecular acting force led to a loose packing motif, and the alteration of molecular packing was responsible for the observed mechanofluorochromic effect.

Exploring the Aggregation and Light-Harvesting Aptitude of Naphthalimide-Based Amphiphile and Non-amphiphile AIEgen

“…Constant endeavor for creating new self-assembled structures by small molecules and systematized organic synthesis is our aim. − In this present work, we have synthesized two amphiphilic and non-amphiphilic compounds based on ACQ-prone, naphthalimide fluorophore. − A small manipulation of the fluorophore caused changes in the aggregation potential. The amphiphilic one bears a 12-carbon long hydrophobic tail, and the other one is devoid of it.…”

Synthesis of 1,1’‐diphenyl‐2‐thienyl‐2’‐(4‐substituted‐styryl)ethenes via oxidative Heck coupling reaction and photophysical studies

“…Naphthalimide-based TPE (5) is highly emissive and mechanochromic in solid state. [4] Coumarin-based TPE regioisomers (6) reported by Myung-Seok Choi and his colleagues [5] showed strong fluorescent intensity and AIE enhancement. Notably, C7 substituted coumarin-TPE showed red-shift and large Stokes shift in its absorption spectrum.…”

“…In one method, the first step is the bromination of TPE by N-bromosuccinimide, followed by the synthesis of phosphonium salt. [4,5] The final step is a Wittig olefination. In another method, a vinyl moiety was first introduced into TPE for further Heck crosscoupling reactions with aryl bromides.…”

Using Room Temperature Phosphorescence of Gold(I) Complexes for PAHs Sensing

“…NI can be easily functionalized allowing not only the possibility to modulate their emission properties on a large scale [ 1 ] but also the design of ligands able to coordinate metal atoms giving rise to NI–metal complexes, though these have been less explored than purely organic NI-derivatives. They are also well known to establish π−π intermolecular contacts giving rise to the formation of aggregates, affecting their resulting luminescence in connection with the aggregation induced emission (AIE) and aggregation caused quenching (ACQ) concept [ 1 , 6 , 10 , 11 ]. Although fluorescence emission is mainly observed in diluted NI-solution samples, phosphorescence may also be achieved in some cases, such as NI-aggregates or when included within a macrocyclic host [ 12 , 13 , 14 ].…”