A5080045183- Advanced Chemical Physics Studies
- Quantum, superfluid, helium dynamics
- Photochemistry and Electron Transfer Studies
- Spectroscopy and Quantum Chemical Studies
- Atomic and Molecular Physics
- Inorganic Fluorides and Related Compounds
- Mass Spectrometry Techniques and Applications
- Physics of Superconductivity and Magnetism
- Laser-induced spectroscopy and plasma
- Free Radicals and Antioxidants
- Crystallography and molecular interactions
- Laser-Matter Interactions and Applications
- Laser-Plasma Interactions and Diagnostics
- Hydrogen Storage and Materials
- Advanced Condensed Matter Physics
- Radiation Effects and Dosimetry
- Spectroscopy and Laser Applications
Universität Innsbruck
2009-2024
Islamic Azad University, Karaj
2015-2023
The most stable structure of cationic (left) and anionic (right) Cu 5 was determined by particularly configurations with He.
Long-lived doubly charged dimers and trimers of krypton xenon are formed by sequential ionization doped helium nanodroplets.
Mass spectroscopic investigations on tetrahydrofuran (THF, C4H8O), a common model molecule of the DNA-backbone, have been carried out. We irradiated isolated THF and (hydrated) clusters with low energy electrons (electron ~70 eV) in order to study electron ionization ionic fragmentation. For elucidation fragmentation pathways, deuterated TDF (C4D8O) was investigated as well. One major observation is that cluster environment shows overall protective behavior THF. However, also new channels...
We report the results of an experimental study electron ionization large helium nanodroplets doped with formic acid (FA). Several homologous series cluster anions are observed, including [FAn-H]-, undissociated FAn-, and these ions complexed one or more H2O. Some major features resemble those observed upon sputtering frozen FA films but they differ significantly from obtained by attachment to bare clusters in gas phase. The FAn- (H2O)[FAn-H]- show abrupt onsets above n = 2 5, respectively. A...
Dissociative electron attachment to all three isomers of dichlorobenzene has been investigated in the energy range from 0 2 eV and gas temperature 391 696 K using a crossed electron-molecular beam apparatus with new temperature-regulated effusive molecular source. In case dissociative channel Cl(-)/1,2-dichlorobenzene Cl(-)/1,4-dichlorobenzene, strong enhancement negative ion production at low energies observed. The low-energy peak increases dramatically when is raised K. Activation for (482...
The smallest doubly charged coronene cluster ions reported so far, Cor152+, were produced by charge exchange between bare clusters and He2+ [H. A. B. Johansson et al., Phys. Rev. A 84, 043201 (2011)]. These dications are at least five times larger than the estimated Rayleigh limit, i.e., size which activation barrier for separation vanishes. Such a large discrepancy is unheard of atomic or molecular clusters. Here we report mass spectrometric observation trimers, electron ionization helium...
We use a novel technique to solvate silver cations in small clusters of noble gases. The involves the formation large, superfluid helium nanodroplets that are subsequently electron ionized, mass-selected by deflection an electric field, and doped with atoms gases (Ng) pickup cells. Excess is then stripped from multiple collisions gas at room temperature, producing cluster ions contain no more than few dozen just (or no) atoms. Under gentle stripping conditions, remain attached ions,...
Laser absorption in the interaction between ultra-intense femtosecond laser and solid density plasma is studied theoretically here intensity range $$ I{\lambda^2} \simeq 10^{14}{-}10^{16}\;{\text{W}}\;{{\text{cm}}^{-2}} \;\upmu{{\text{m}}^{2}} . The collisionless effect found to be significant when incident less than 10^{16}\;{\text{W}}\;{{\text{cm}}^{-2}}\;\upmu{{\text{m}}^{2}} In current work, propagation of a high-frequency electromagnetic wave, for underdense presence an external...
Polyacenes among other polycyclic aromatic hydrocarbons (PAHs) were suggested to be abundant in the dense regions of interstellar medium (ISM) and responsible for some diffuse bands (DIBs). The identification DIB carriers requires laboratory spectra cold cations comparison with astrophysical observations. We employed He-tagging spectroscopy record spectrum tetracene cations. In contrast previous measurements polyacene cations, we found very narrow absorption +. This makes detection...
We underscore a solid agreement between experimental and computational studies on solvation of pristine/protonated Cu n + ( = 1–2) in H 2 . For instance, with 1, the initial shell comprises four covalently bound ; subsequent ones are non-covalent.
Dissociative electron attachment to three isomers of bromo-chlorotoluene was investigated in the energy range from 0 2 eV for gas temperatures 392-520 K using a crossed electron-molecular beam apparatus with temperature regulated effusive molecular source. For all molecules, both Cl− and Br− are formed. The ion yields halogenides show pronounced effect. In case Br−, influence can be observed at threshold peak close eV. population molecules that have some their out-of-plane modes excited...
Abstract 1-(4-bromo-3-nitrophenyl)-1-propanone (BNPP) is a proposed potential radiosensitizer that might combat hypoxia in tumor cells. Here, we study the electron-induced decomposition of BNPP gas phase using crossed electron-molecular beam experiment supported by quantum chemical calculations. We show attachment single electron induces dissociation molecule, both directly and upon molecular rearrangement. The most prominent channel includes formation Br – at energy ~0 eV, parent anion...
Complexes of atomic gold with a variety ligands have been formed by passing helium nanodroplets (HNDs) through two pickup cells containing vapor and the another dopant, namely rare gas, diatomic molecule (H2, N2, O2, I2, P2), or various polyatomic molecules (H2O, CO2, SF6, C6H6, adamantane, imidazole, dicyclopentadiene, fullerene). The doped HNDs were irradiated electrons; ensuing cations identified in high-resolution mass spectrometer. Anions detected for benzene, fullerene. For most L,...
Abstract Using a high-resolution electron monochromator, we studied the formation of (H 2 O) n ⩽19 − cluster ions upon collisions free low-energy electrons with water clusters embedded in helium droplets. The anion efficiency curves as function initial energy were measured for sizes = 2–8, 10, 13, 16, and 19. present experimental results show that shape resonance yields is dependent on size anion. are discussed terms different states available excess from linear structure to...