The propensity of 5-formyluracil and 5-formylcytosine, i.e. oxidative lesions and epigenetic intermediates, in acting as intrinsic DNA photosensitizers is unraveled by using a combination of molecular modeling, simulation and spectroscopy. Exploration of potential energy surfaces and non-adiabatic dynamics confirm a higher intersystem crossing rate for 5-formyluracil, whereas the kinetic models evidence different equilibria in the excited states for both compounds.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1039/d0cc01132k | DOI Listing |
Photochem Photobiol
January 2025
Departamento de Química, Universidad Nacional de Rio Cuarto, Río Cuarto, Argentina.
In 1963, Eduardo Lissi and Juan Grotewold started a chemical kinetics and photochemistry group at the School of Sciences at the University of Buenos Aires (Facultad de Ciencias Exactas y Naturales, FCEN, UBA). Political circumstances in Argentina and in Chile were a great determinant of the evolution, dispersion, and re-encounters of the group members. The initial graduate students in the group developed their own research groups working in various Countries and on a variety of projects.
View Article and Find Full Text PDFJ Chem Phys
January 2025
Science Institute and Faculty of Physical Sciences, University of Iceland, Reykjavík, Iceland.
Understanding the ultrafast vibrational relaxation following photoexcitation of molecules in a condensed phase is essential to predict the outcome and improve the efficiency of photoinduced molecular processes. Here, the vibrational decoherence and energy relaxation of a binuclear complex, [Pt2(P2O5H2)4]4- (PtPOP), upon electronic excitation in liquid water and acetonitrile are investigated through direct adiabatic dynamics simulations. A quantum mechanics/molecular mechanics (QM/MM) scheme is used where the excited state of the complex is modeled with orbital-optimized density functional calculations while solvent molecules are described using potential energy functions.
View Article and Find Full Text PDFChem Sci
January 2025
Institute of Polymer Optoelectronic Materials and Devices, Guangdong Basic Research Center of Excellence for Energy & Information Polymer Materials, Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials, Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology Guangzhou 510640 China
The efficient harvesting of triplet excitons is key to realizing high efficiency blue fluorescent organic light-emitting diodes (OLEDs). Triplet-triplet annihilation (TTA) up-conversion is one of the effective triplet-harvesting strategies. However, during the TTA up-conversion process, a high current density is necessary due to the competitive non-radiative triplet losses.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Institut für Organische Chemie, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.
Modulation of optical properties through smart protein matrices is exemplified by a few examples in nature such as rhodopsin (absorption wavelength tuning) and the green fluorescence protein (emission), but in general, the scope found in nature for the matrix-controlled photofunctions remains rather limited. In this review, we present cyclophane-based supramolecular host-guest complexes for which electronic interactions between the cyclophane host and mostly planar aromatic guest molecules can actively modulate excited-state properties in a more advanced way involving both singlet and triplet excited states. We begin by highlighting photofunctional host-guest systems for on-off fluorescence switching and chiroptical functions using bay-functionalized perylene bisimide cyclophanes.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China.
Flavonoids, a group of natural pigments, have attracted notable attention for their intrinsic fluorescent bioactive properties and potential therapeutic implications. Recent studies have suggested that the photoexcitation of specific flavonoids can also lead to the formation of triplet states, thereby potentially enhancing their applications in photoactivated antioxidant mechanisms. However, the crucial mechanism details about triplet state formation are still poorly understood.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!