Full-color tunable mechanofluorochromism and excitation-dependent emissions of single-arm extended tetraphenylethylenes

Abstract

Single-arm extended tetraphenylethylene derivatives exhibit full-color tunable mechanofluorochromism and excitation-dependent emissions.

Tunable Emission from Fluorescent Organic Nanoparticles in Water: Insight into the Nature of Self‐Assembly and Photoswitching

“…This implies that all the emission bands in the profile stretching from 420 to 550 nm originate from a single ground state. This excitation‐independent nature of Pytpy emission can probably be explained by its ability to undergo strong ordering during self‐assembly . The various emission bands, including bands with large bathochromic shifts, are exclusively due to excited‐state effects.…”

“…This excitation-independentn ature of Pytpy emission can probably be explained by its ability to undergo strongo rdering during self-assembly. [24] The variouse mission bands, including bands with large bathochromic shifts, are exclusively due to excitedstate effects. The emission bands at about 465 and about 480 nm are expected to originate from the twisted-statec onformationo ft he molecules in the free state, while the redshifted emissionm axima (at % 506 and % 535 nm) can be attributed to the more planar conformation of the fluorophores in the aggregated state [25] As expected, emission spectra of Pytpy in highly viscousm edium( 50 %g lycerol/water) indeed showed enhancement of emission intensity of the band at about 510 nm and almost no change in the band at about 470 nm (Figure 10 d).…”

A Dual‐Stimuli‐Responsive Coordination Network Featuring Reversible Wide‐Range Luminescence‐Tuning Behavior

“…First, many of them show abrupt two‐color switching, rather than a smooth wavelength shift, and a second force is always necessary for reversing the change . Second, a minority of them exhibit a multistimuli response in the form of individual events (e.g., conformational variation, molecular alignment modulation, crystal‐to‐amorphous transition) characterized by a set of discrete luminescence peaks . Finally, their dynamic structural changes are difficult to control and are usually presented without single‐crystal data …”

A Dual‐Stimuli‐Responsive Coordination Network Featuring Reversible Wide‐Range Luminescence‐Tuning Behavior

“…[1] To date,t his class of "smart" luminescent materials are mainly organic/metallorganic molecules [2] or polymers, [3] which, however,h ave several limitations.F irst, many of them show abrupt two-color switching, rather than as mooth wavelength shift, and as econd force is always necessary for reversing the change. [4,5] Second, am inority of them exhibit am ultistimuli response in the form of individual events (e.g., conformational variation, [6] molecular alignment modulation, [7] crystal-to-amorphous transition [8][9][10] )characterized by aset of discrete luminescence peaks. [7,9] Finally,t heir dynamic structural changes are difficult to control and are usually presented without singlecrystal data.…”