In Situ Photoconversion of Multicolor Luminescence and Pure White Light Emission Based on Carbon Dot-Supported Supramolecular Assembly

Abstract

Constructing multicolor photoluminescence materials that allow for the integration of suitable external stimuli in order to control luminescence color conversions is a challenging objective. Multicolor luminescent output that is regulated in an in situ photo-controlled manner is not a common phenomenon. Herein, a photoluminescent supra­molecular assembly, prepared in two stages, is described that displays in situ photo-tuning broad-spectrum output. Benefiting from the reversible photo-switched constitutional interconversion of diaryl­ethenes, the fluorescence of a guest molecule, styryl­pyridinium-modified diaryl­ethene, can be switched on/off by alternating ultraviolet and visible light irradiation. Upon complexation of this guest with a host, cucurbit[8]­uril, the fluorescence intensity of the resulting binary supra­molecular nanofiber shows a drastic enhancement when compared with that of the free guest, which can also be quenched and recovered reversibly by light irradiation. Significantly, such cationic supra­molecular nanofibers also interact with anionic carbon dots to form broad-spectrum output ternary supra­molecular assemblies, the fluorescence of which can be changed efficiently from yellow to blue in an in situ photo-controlled manner. Pure white light emission can be realized expediently in the luminescence color-conversion process. The use of light as an external stimulus to regulate fluorescent color conversion provides us with an opportunity to design and construct more advanced anti-counterfeiting materials as well as visual display instruments.

Photo‐Powered Collapse of Supramolecular Polymers Based on an Overcrowded Alkene Switch

“…Light‐responsive supramolecular polymers are of great importance owing to the clean, fast, non‐invasive and handy character of light stimulus –––. Light‐driven overcrowded alkene switches (OAS) can be designed into a class of well‐known molecular motors which can perform molecular‐scale rotation driven by light and heat, which have been proved reliable in many potential applications, such as asymmetric catalysis, amphiphilic system, ion recognition, and chirality switching .…”

Recent advances in crystalline carbon dots for superior application potential

“…Initial reports indicate the presence of a large extent of sp 3 carbon atoms inside Cdot structures. 79,[120][121][122][123] They exhibit a broad diffraction pattern in the powder XRD analysis with no characteristic lattice fringes corresponding to interlayer spacings. In addition, broad D-and G-bands could be observed in Raman spectrometry along with high intensity ratios between the two, i.e., I D /I G ratios.…”

Host–guest interactions in nor-seco-cucurbit[10]uril: novel guest-dependent molecular recognition and stereoisomerism

“…For example, cucurbit[8]uril (Q[8] or CB[8]), a large homologue of the Q[ n ] family, is unique because of its ability to bind two hetero- and homo-aromatic guests in its cavity through host-stabilized charge-transfer or π–π interactions [14–15]. This novel property of Q[8] has been utilized as molecular container for biological substrates [16–17], as well as in the construction of various supramolecular assemblies with specific structures and properties [18–22]. However, forming ternary complexes with Q[8] is challenging because the number of aromatic-derived water-soluble recognition motifs remains limited.…”