Tetrathienylethene‐based Positional Isomers with Aggregation‐induced Emission Enabling Super Red‐shifted Reversible Mechanochromism and Naked‐eye Sensing of Hydrazine Vapor

Abstract

AIE-active positional isomers, TTE-o-PhCHO, TTEm-PhCHO and TTE-p-PhCHO, tetrathienylethene (TTE) derivates with peripherally attached ortho-/meta-/para-formyl phenyl groups, were designed and synthesized. The formyl substitution position can effectively modulate their photophysical properties, mechanochromism and fluorescent response to hydrazine. TTE-o-PhCHO and TTE-m-PhCHO exhibit remarkable AIE characteristics, and TTE-p-PhCHO possesses aggregation-induced emission enhancement performance. They all exhibit high contrast mechanochromism, and TTE-m-PhCHO shows larger red-shift (164 nm) thanTTE-o-PhCHO (104 nm) and TTE-p-PhCHO (125 nm) due to the more twisted molecular conformation and much looser molecular packing. Moreover, TTE-o-PhCHO with a higher contrast color change can be used as ink-free rewritable paper. In addition, TTE-p-PhCHO, as a turn-on fluorescent probe, can selectively detect hydrazine with significant color changes that are visible by the naked eye . Therefore, the position dependence of groups would be an effective method to modulate the molecular arrangement, as well as develop AIE compounds for mechano-stimuli responsive materials, ink-free rewritable papers and chemosensors.[a] Dr.Supporting information and the ORCID identification number(s) for the author(s) of this article can be found under: https://doi.

The locations of triphenylamine and tetraphenylethene on a cyclohexyl ring define a luminogen as an AIEgen or a DSEgen

“…5). Although the significant impact of positional isomerization on the PL behaviors has been well known for luminogens with conjugated frameworks, [47][48][49] to our knowledge, this is the first time that such a transformation from an AIEgen to a DSEgen by switching the connecting site but keeping the same functional group on a saturated stator has been achieved.…”

Pyrene and triphenylamine substituted cyanostyrene and cyanostilbene derivatives with dual-state emission for high-contrast mechanofluorochromism and cell imaging

“…The decrease of Φ upon grinding could be a result of changes in molecular packing. 43 To understand the mechanism of MFC behavior of the powders PYTPA and PYPHTPA, the fluorescence lifetimes and powder X-ray diffraction (PXRD) patterns of PYTPA and PYPHTPA before and after grinding were measured (Fig. 6a-d).…”

Substituent Effect on Vibrationally Resolved Absorption Spectra and Exciton Dynamics of Dipyrrolonaphthyridinedion Aggregates

“…Experimentally, a variaty of techniques have been proposed to regulate the intermolecular packing arrangement to improve the device efficiency, such as modulating the substitution positions, increasing the lengths of chains or directly adopting the highpressure technique. [5][6][7][8][9][10] To microscopically reveal the underlying correlations between properties and stacking structures, one further requires electronic structure calculations and photo-induced carrier dynamic simulations. Dipyrrolonaphthyridinedion (DPND) has a series of cross-conjugated skeletons composed of electron-rich pyrrole rings and electron-poor carbonyl moieties, and is a kind of effective singlet fission materials with exceptional photophysical properties [11][12][13] such as suitable energy level, good stability, high fission efficiency and adjusting molecular structures.…”