In Situ Generation of 1-Acetylpyrene as a Visible-Light Photocatalyst for the Thia-Paternò-Büchi Reaction.

The thia-Paternò-Büchi reaction represents a straightforward approach to build thietane cores. Unfortunately, the significant instability of thiocarbonyls, particularly thioketones and thioaldehydes, has hitherto rendered this photochemical [2+2]-cycloaddition underexploited. To address this limitation, we report herein a visible-light photochemical domino reaction including: the in situ generation of thiocarbonyls though a Norrish type II fragmentation of pyrenacyl sulfides, and the aforementioned thia-Paternò-Büchi reaction with various non-volatile electron-rich alkenes.

Cascade Fluorescence Modulation in Photochromic Microcapsules.

Certain derivatives of terarylene are able to undergo a highly efficient oxidative cycloreversion cascade effect, a ring opening reaction with quantum yields above unity, resulting in a colored-to-colorless transition in solution. In the presence of chloroform, high-energy UV and X-rays can trigger this phenomenon, potentially acting as a visual detection system for ionizing radiation. However, chloroform is sensitive to different irradiation wavelengths without distinction, making it difficult to adapt to a reusable device.

Feed restriction affects milk performances and decreases milk lipolysis in dairy ewes.

Spontaneous lipolysis results in the breakdown of milk fat by the lipoprotein lipase (EC: 3.1.1.

C-Symmetric Luminescent Diketone with Amido-Linkage as a Polymorphic Fluorescence Emitter.

The study introduces a novel C-symmetric β-diketone compound, BTA-D3, and its monomeric counterpart, D, with a focus on their synthetic procedure, photophysical properties and aggregation behavior. Both compounds exhibit characteristic absorption and weak fluorescence in solution, with BTA-D3 displaying higher absorption coefficients due to its larger number of diketone units. Density Functional Theory (DFT) calculations suggest increased co-planarity of diketone groups in BTA-D3.