Multistimuli Sensitive Behavior of Novel Bodipy‐Involved Pillar[5]arene‐Based Fluorescent [2]Rotaxane and Its Supramolecular Gel

Abstract

Fluorescent [2]rotaxane BC12P5 is successfully constructed with 1,4‐diethoxypillar[5]arene as wheel over a long alkyl axle with Bodipy chromophore as one stopper for the first time. NMR spectra clearly reveal its molecular shuttle nature triggered by multiple external stimuli including solvent polarity and temperature. In particular, the fluorescence nature introduced into [2]rotaxane BC12P5 renders it a good sensor for the external stimuli. Nevertheless, the supramolecular gel successfully fabricated from this novel rotaxane system via self‐assembly in dimethyl sulfoxide (DMSO) also shows reversible gel–sol phase transition upon multiple external stimuli such as heating/cooling, shaking/resting, or the addition of different anions. Interestingly, exposure of the supramolecular gel film to HCl or ammonia vapor induces the change in the film fluorescence intensity, endowing this system with a potential application in gas detecting.

Self-Assembly of Bodipy-Derived Extended π-Systems

“…Molecular recognition properties of host and guest moieties have been utilized to prepare a Bodipy-based fluorescent gel that responds to multiple stimuli such as temperature, solvent polarity and acid/base vapors. 55 A host-guest complex (15) was synthesized with two units such as 1,4-diethoxypillar [5]arene as a wheel and a long alkyl chain with Bodipy stopper as an axle (Figure 6a). Detailed 1 H NMR studies revealed the temperature and solvent polarity dependent shuttling of the wheel of rotaxane 15.…”

Research Progress Review of Preparation and Applications of Fluorescent Hydrogels

“…At present, rotaxane usually prepares supramolecular gels with multiple stimulus responses by self-assembly in solution [43]. Sun et al [44] prepared the first rotaxane with fluorescent functional group based on BODIPY and aromatics. en, using the rotational alkane as gelation factor, by means of the π-π interaction between the phenylene parts of the adjacent column aromatic ring of the rotaxane, noncovalent action such as π-π interaction between BODIPY and imidazolium parts, the 3D crosslinking network is finally self-assembled (Figure 6).…”

“…(b) Schematic diagram of self-assembly of BC12P5 in supramolecular gels. (c) SEM images of rotan-based supramolecular gels formed in DMSO (reprinted from[44]).…”

Macrocyclic Arenes Functionalized with BODIPY: Rising Stars among Chemosensors and Smart Materials

“…Rotaxanes and catenanes are two archetypal examples of mechanically interlocked molecules [105]. Xiao and coworkers constructed the first BODIPY-derived fluorescent [2]rotaxane (Figure 21), which showed unique molecular shuttle properties under multiple external stimuli including solvent polarity and temperature [106]. Here, 1,4-diethoxypillar [5]arene 30 acted as the wheel, while guest G4 was introduced as the axle where a BODIPY chromophore and arylcarbamic group were introduced as the stoppers.…”