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This study focuses on the design, eco‐friendly synthesis, and characterization of several novel three‐legged triphenylamine derivatives. By performing Sonogashira couplings of functionalized aryl iodides with tris(4‐ethynylphenyl)amine in glycerol, a readily available bio‐derived solvent, we achieved the synthesis of target products in short times and high yields, up to 94 %, with consistently lower E‐factors and reduced costs compared to standard conditions using toluene as the reaction medium. The target molecules possess a D‐(π‐A)₃ or D‐(π‐D)₃ structure, where an electron‐donating core connects to three electron‐donating (D) or electron‐accepting (A) peripheral aromatic subunits through an acetylene spacer. Their main optical and electronic properties have been determined experimentally and by DFT simulations and suggest a possible implementation in energy conversion technologies such as luminescent solar concentrators (LSCs) and perovskite solar cells (PSCs). [ABSTRACT FROM AUTHOR]

The Mn4CaO5 cluster of photosystem II promotes a crucial step in the oxygenic photosynthesis, namely, the water-splitting reaction. The structure of such cluster in the S1 state of the Kok-Joliot's cycle has been recently resolved by femtosecond X-ray free-electron laser (XFEL) measurements. However, the XFEL results are characterized by appreciable discrepancies with previous X-ray diffraction (XRD), as well as with S1 models based on ab initio calculations. We provide here a unifying picture based on a combined set of DFT-based structures and molecular dynamics simulations of the S0 and S1 states. Our findings indicate that the XFEL results cannot be interpreted on the grounds of a single structure. A combination of two S1 stable isomers together with a minority contribution of the S0 state is necessary to reproduce XFEL results within 0.16 Å. [ABSTRACT FROM AUTHOR]