Nonconventional Luminophores Research Articles

Intrinsic Luminescence from Nonaromatic Biomolecules.

Novel emitters that do not contain traditional chromophores but only electron-rich moieties (e. g. amine, C=O, -OH, ether, and imide), which are classified as nonconventional luminophores, have been more frequently reported. Although more and more examples have been demonstrated, their emission mechanism remains unclear. The clustering-triggered emission (CTE) mechanism has previously been proposed to rationalize the luminescence of unconventional chromophores. Moreover, great attention has been paid to the distinctive inherent luminescence from nonaromatic biomolecules such as cellulose, starch, sugars, and nonaromatic amino acids and proteins. In this Review, we summarize these unconventional biomolecular luminophores and apply the CTE mechanism to rationalize such a phenomenon. This Review may shed new light on the understanding of intrinsic emission of nonaromatic biomolecules and decipher the intrinsic fluorescence from cells and tissues.

Nonconventional luminophores with unprecedented efficiencies and color-tunable afterglows

Highly efficient nonconventional luminophores with unprecedented efficiency of up to 87.5% and readily tunable p-RTP were developed.

Clustering‐Triggered Efficient Room‐Temperature Phosphorescence from Nonconventional Luminophores

Pure organic room-temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Herein, we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin-orbit coupling and boosts the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5 % is obtained. Further control experiments testify the crucial role of through-space delocalization on the emission. These results will spur the future fabrication of nonconventional phosphors and advance the understanding of the underlying emission mechanism.

Sulphur-containing nonaromatic polymers: clustering-triggered emission and luminescence regulation by oxidation

Sulphur-containing nonconventional luminophores with clustering-triggered emission characteristics are developed, whose emission is readily modulated through oxidation.

Emission and Emissive Mechanism of Nonaromatic Oxygen Clusters.

Nonaromatic luminophores without remarkable conjugates have aroused great attention. Their emission mechanism, however, remains an open question. Meanwhile, previous studies generally focus on aliphatic amine and/or carbonyl-containing systems; those with merely oxygen moieties (i.e., ether, hydroxyl) are scarcely touched. Recently, the clustering-triggered emission (CTE) mechanism is proposed to rationalize the emission of nonconventional luminophores, according to which compounds bearing purely oxygen moieties can also be emissive. To check this conjecture, herein, both nonaromatic compound of xylitol and polymers of PEG and F127 are studied, which are found to be emissive in concentrated solutions and solids. Furthermore, cryogenic-persistent phosphorescence of the compounds and even persistent room temperature phosphorescence of xylitol crystals are observed. Additionally, their potential application as Fe3+ sensors is demonstrated. These results not only verify the rationality of the CTE mechanism but also suggest the possibility to discover and design new luminophores according to it.