Clusteroluminescence from Cluster Excitons in Small Heterocyclics Free of Aromatic Rings

The study on <a></a><a>non-conventional luminescence</a> is important for revealing the luminescence of natural systems and has gradually drawn the attention of researchers in recent years. However, the underlying mechanism is still inexplicable. Herein, the luminescence behaviors of two series of simple, heteroatom-containing small molecules without aromatic rings, <i>i.e</i>. maleimide and succinimide derivatives, are studied to gain further mechanistic insight into the non-conventional luminescence process. It has been unveiled that <a>all the molecules exhibit bright and visible luminescence in concentrated solution and solid state </a>and the formation of clusters is the root cause for such behaviors, which can effectively increase the possibility of both the non-radiative n-π* and favorable π-π* transitions and stabilize the excitons formed in the excited state. The distinctive luminescent phenomena and intriguing mechanism presented in this work will be significant for understanding the mechanism of clusteroluminescence and provide new strategies for the rational design of novel luminescent materials.

Clusteroluminescence from Cluster Excitons in Small Heterocyclics Free of Aromatic Rings

The study on <a></a><a>non-conventional luminescence</a> is important for revealing the luminescence of natural systems and has gradually drawn the attention of researchers in recent years. However, the underlying mechanism is still inexplicable. Herein, the luminescence behaviors of two series of simple, heteroatom-containing small molecules without aromatic rings, <i>i.e</i>. maleimide and succinimide derivatives, are studied to gain further mechanistic insight into the non-conventional luminescence process. It has been unveiled that <a>all the molecules exhibit bright and visible luminescence in concentrated solution and solid state </a>and the formation of clusters is the root cause for such behaviors, which can effectively increase the possibility of both the non-radiative n-π* and favorable π-π* transitions and stabilize the excitons formed in the excited state. The distinctive luminescent phenomena and intriguing mechanism presented in this work will be significant for understanding the mechanism of clusteroluminescence and provide new strategies for the rational design of novel luminescent materials.

Each phenyl group performs its own functions on luminescence: phenyl substituted effect in tetraphenylpyrazine

Three phenyl groups of TPP derivatives affect the luminescence process in various modes. TPPs show AIE thanks to the ortho substituted groups, while meta and para groups can modulate their luminescence in different extents.

Alpha Radiation-Induced Luminescence by Am-241 in Aqueous Nitric Acid Solution

When exposed to air, alpha particles cause the production of light by exciting the molecules surrounding them. This light, the radioluminescence, is indicative of the presence of alpha radiation, thus allowing for the optical sensing of alpha radiation from distances larger than the few centimeters an alpha particle can travel in air. While the mechanics of radioluminescence in air and other gas compositions is relatively well understood, the same cannot be said about the radioluminescence properties of liquids. Better understanding of the radioluminescence properties of liquids is essential to design methods for the detection of radioactively contaminated liquids by optical means. In this article, we provide radioluminescence images of Am-241 dissolved in aqueous nitric acid ( HNO 3 ) solution and present the recorded radioluminescence spectrum with a maximum between 350 nm and 400 nm , and a steep decrease at the short wavelength side of the maximum. The shape of the spectrum resembles a luminescence process rather than Cerenkov light, bremsstrahlung, or other mechanisms with broadband emission. We show that the amount of light produced is about 150 times smaller compared to that of the same amount of Am-241 in air. The light production in the liquid is evenly distributed throughout the sample volume with a slight increase on the surface of the liquid. The radioluminescence intensity is shown to scale linearly with the Am-241 concentration and not be affected by the HNO 3 concentration.

Spatially confined luminescence process in tip-modified heterogeneous-structured microrods for high-level anti-counterfeiting

Spatially confined UC and DC luminescence in a single microrod promote the luminescence anti-counterfeiting level.