Highly Reversible Supramolecular Light Switch for NIR Phosphorescence Resonance Energy Transfer

Abstract

Although purely organic room‐temperature phosphorescence (RTP) has drawn widespread attention in recent years, regulatable phosphorescence resonance energy transfer (PRET) supramolecular switch is still rare. Herein, single molecular dual‐fold supramolecular light switches, which are constructed by phenylpyridinium salts modified diarylethene derivatives (DTE‐Cn, n = 3, 5) and cucurbit[8]uril (CB[8]) are reported. Significantly, biaxial [3]pseudorotaxane displayed efficiently reversible RTP after binding with CB[8] and the phosphorescence quenching efficiency is calculated up to be 99%. Furthermore, the binary supramolecular assembly can coassemble with Cy5 to form ternary supramolecular assembly showing efficiently PRET, which is successfully applied in switchable near infrared (NIR) mitochondria‐targeted cell imaging and photocontrolled data encryption. This supramolecular strategy involving energy transfer provides a convenient approach for phosphorescent application in biology and material fields.

A supramolecular strategy for gated photochromism in aqueous solution and solid state

“…[29][30][31] Besides, note that the binding mode of CB [10]ÁGo was also found to be quite different from that of the previous CB-DTE-involved host-guest complex. [22][23][24]32 In those works, whether or not the substituents on the thiophene group or the DTE backbone were encapsulated in the cavity, the host molecule did not block the photoactivity of the DTE unit, meaning that the conformation of these DTE guests was still favorable for the photoreaction. The stability of CB [10]Á Go can be attributed to the ion-dipole interactions between CQO of CB [10] and + NMe 3 groups of Go (Fig.…”

“…19,20 It has been proved that CB[n] could greatly affect both photophysical and photochemical properties of DTE in aqueous solution. [21][22][23][24] And CB [8] was employed to construct a gated photochromism system based on DTE in aqueous solution. 25 In the CB[n] family, CB [10] has the biggest rigid cavity, with recognition properties rather distinctive from those of smaller CB[n]s. 26 A DTE covalently modified to a moderate extent has been shown to be wholly trapped in CB [10], 23 suggesting that the host-guest complex in the solid state may maintain its photochemistry in the solution phase.…”

Near‐Infrared Phosphorescent Switch of Diarylethene Phenylpyridinium Derivative and Cucurbit[8]uril for Cell Imaging

“…These results suggest that TP and DTE-TP adopted the same folding configuration within the CB [8] cavity, and that supramolecular polymers did not form. [28][29][30][31] The complexation process was also examined using CB [7] and CB [6] for comparison. Upon the addition of CB [7], the H f,g protons shifted upfield, whereas the H a,i protons shifted downfield, implying that CB [7] could also accommodate the phenylpyridinium moiety in its cavity, while the alkyl and thiophene segments were located outside the cavity (Figure S16a, Supporting Information).…”

Visible Light Activated Organic Room‐Temperature Phosphorescence Based on Triplet‐to‐Singlet Förster‐Resonance Energy Transfer

“…Furthermore, they used supramolecular hybrid phosphors as a lightharvesting scaffold to achieve delayed fluorescence from orthogonally anchored Sulforhodamine acceptor dyes via an efficient TS-FRET in an aqueous solution. [8] Liu and co-workers have shown a regulatable TS-FRET supramolecular switch [9] and an ultrahigh supramolecular cascaded phosphorescence-capturing aggregate [10] constructed by multivalent co-assembly of cucurbit [7]uril (CB[7]) and amphipathic sulfonatocalix[4]arene (SC4AD). Simultaneous and efficient energy transfer from both donating singlet and triplet states of a single photoluminescent molecular species could be demonstrated by Reineke and co-workers.…”