Joint Meeting Prague–Innsbruck

We aim to investigate the FLASH effect in well-defined solutions of bioactive molecules using short-pulse X-ray free-electron laser (XFEL) radiation. Radiotherapy operating at ultra-high-dose rates (UHDR, > 40 Gy/s) and short irradiation times (< 500 ms) shows preserved tumor-control efficacy with markedly reduced toxicity towards normal tissues, a phenomenon referred to as the FLASH effect...

Low-energy electrons (LEEs), produced during the interaction of ionizing radiation with matter, can induce molecular transformations through the formation and decay of transient negative ions (TNIs) [1]. Brominated triazoles are of interest in this context because they exhibit efficient electron attachment and a variety of competing decay pathways [2]. While electron attachment to isolated...

This contribution provides an overview of our recent work on the reactivity of low-energy electrons with molecules containing an azole ring, from pilot studies with tetrazoles [1] to detailed exploration of complex roaming dynamics in triazoles [2]. Conclusions about the potential of low-energy electrons to induce molecular isomerization and decay of these highly stable molecules are drawn...

Polycyclic aromatic hydrocarbon (PAH) molecules can be found in atmospheric aerosols as a result of combustion processes. In addition, they are omnipresent in interstellar space, where they can also condense in icy grain mantles. Thus, these species play important role in atmospheric chemistry and astrochemistry, and investigation of PAH clusters and their complexes with other molecules can...

The search for molecular carriers of diffuse interstellar bands (DIBs) remains one of the longest-standing open problems in astrophysics. While $\mathrm{C}_{60}^+$ is the only DIB carrier firmly identified so far [1], modern high-resolution observations suggest that small molecules, including diatomics, may contribute to some DIB systems [2]. However, accurate experimental or theoretical...

The integration of DNA origami with microscale objects provides a powerful route for creating hybrid colloidal architectures with programmable geometry and multifunctionality complexity. However, achieving precise bottom-up assembly of micron-sized particles remains a major challenge. Here, we present a fully bottom-up strategy for fabricating Janus-type optomechanical probes by interlinking...

Triazoles and their derivatives are widely used structural units in chemistry and pharmaceuticals that are valued in click chemistry for their high stability. However, the addition of lowenergy electrons can lead to significant molecular fragmentation and rearrangement, thereby opening potential pathways for "retro-click" reactions [1]. In this work, we investigated the electron-induced...

Understanding non-adiabatic processes is essential for describing many chemical and physical phenomena, particularly in transition-metal complexes and photocatalysis. Their simulation requires potential energy surfaces and electronic couplings, but direct electronic-structure calculations are computationally demanding. Moreover, adiabatic potential energy surfaces become non-smooth near...

Understanding the molecular mechanisms of radiation-induced DNA damage across diverse environments is critical for advancing applications in cancer radiotherapy, nanodosimetry, DNA-templated lithography, and DNA-based archival data storage [1]. Strategically modulating the response of DNA to ionizing radiation (i.e., using radiomodulators) enables precise control and optimization of processes...

Hydrogen peroxide (H₂O₂, HP) belongs to the class of reactive oxygen species and serves as an important reservoir of radical species due to its relatively weak O–O bond. In biological environments, leakage of electrons from the electron transport chain may induce dissociative electron attachment to H₂O₂, leading to the formation of hydroxide anions (OH⁻). Both OH radicals and OH⁻ are highly...

Hydrated clusters of four simple PAHs – naphthalene, cyanonaphthalene, anthracene, and phenanthrene – were investigated. The clusters were produced in a supersonic expansion, ionized by electron impact, and the resulting ions were analyzed by a reflectron time-of-flight mass spectrometer. The mass spectra reveal a pronounced enhancement of the signal intensities for the cluster ions...