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An editorial is presented which expresses the views on recent advances in excited-state processes in biomolecules, highlighting both experimental and computational approaches. Topics include the impact of light on biomolecules, innovations in spectroscopic techniques for studying these processes, and the development of photoconvertible fluorescent proteins for bioimaging.

Biomass represents an abundant and renewable source of raw materials that can be effectively converted into intermediates and base chemicals. Among these, levulinic acid has garnered significant attention due to its direct derivation from lignocellulosic biomass and the presence of two functional groups, a carboxylic acid, and a ketone, enabling diverse transformations into valuable products. Levulinic acid esters have already found applications in various industrial sectors such as cosmetics, plasticizers, and solvents. In this study, a broad array of alkyl levulinates has been successfully synthesized through homogeneous transesterification catalyzed by Lewis acids. A systematic screening of a library of μ‐oxo‐dinuclear Fe(III) salen complexes has been conducted, aiming to elucidate the impact of steric and electronic properties of their substituents. A complementary theoretical‐computational study based on quantum mechanics calculations and machine learning regression techniques has been employed to unravel the relationship between the structure of the catalysts and their corresponding properties, shedding light on the key factors influencing their catalytic performance. [ABSTRACT FROM AUTHOR]

Photo‐induced charge transfer (CT) states are pivotal in many technological and biological processes. A deeper knowledge of such states is mandatory for modeling the charge migration dynamics. Real‐time time‐dependent density functional theory (RT‐TD‐DFT) electronic dynamics simulations are employed to explicitly observe the electronic density time‐evolution upon photo‐excitation. Asymmetrically substituted indenotetracene molecules, given their potential application as n‐type semiconductors in organic photovoltaic materials, are here investigated. Effects of substituents with different electron‐donating characters are analyzed in terms of the overall electronic energy spacing and resulting ultrafast CT dynamics through linear response (LR‐)TD‐DFT and RT‐TD‐DFT based approaches. The combination of the computational techniques here employed provided direct access to the electronic density reorganization in time and to its spatial and rational representation in terms of molecular orbital occupation time evolution. Such results can be exploited to design peculiar directional charge dynamics, crucial when photoactive materials are used for light‐harvesting applications. [ABSTRACT FROM AUTHOR]

The physicochemical effects modulating the conformational behavior and the rate of intramolecular dissociative electron transfer in phthalimide - Aib(sub n)-peroxide peptides (n=0-3) were studied by an integrated density functional/continuum solvent model. The study of the dependence of the frontier orbital on the length and on the conformation of the peptide bridge suggested that for n=3 the process could be influenced by a 3(sub 10)-->alpha-helix conformational transition of the peptide chain.

Research into possible radical reaction products issuing from H-atom addition to cytosine is presented. It was found that the 5,6-dihydrocytos-5yl radical is effectively planar, while the 5,6-dihydrocytos-6yl radical has a half-chair conformation at low temperature.