Category Ranking
98%
Total Visits
921
Avg Visit Duration
2 minutes
Citations
20
Article Abstract
In the present work, we studied the photoinduced ion chemistry of the halogenated pyrimidines, a class of prototype radiosensitizing molecules, in the energy region 9-15 eV. The work was stimulated by previous studies on inner shell site-selective fragmentation of the pyrimidine molecule, which have shown that the fragmentation is governed by the population/formation of specific ionic states with a hole in valence orbitals, which in turn correlate to accessible dissociation limits. The combined experimental and theoretical study of the appearance energies of the main fragments provides information on the geometric structure of the products and on the role played by the specific halogen atom and the site of halogenation in the dissociation process. This information can be used to gain new insights on the elementary mechanisms that could possibly explain the enhanced radiation damage to the DNA bases or to the medium in which the bases are embedded, thereby contributing to their radiosensitizing effect.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1007/s13361-013-0783-x | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Halogen Migration in the Photofragmentation of Halothane.
Molecules
July 2025
ISM-CNR-Istituto di Struttura della Materia, Area della Ricerca di Roma 1, CP 10, 00016 Monterotondo Scalo, Italy.
The photofragmentation of halothane (CFCHBrCl) was studied with synchrotron radiation by photoionization efficiency (PIE) measurements and photoelectron-photoion coincidence (PEPICO) experiments, as well as by a theoretical exploration of potential energy surfaces. Among the other fragments, the formation of the CHClF and CHBrF ions, which involves the transfer of a F atom between the two moieties of the parent molecule, was observed. To understand the mechanisms leading to the halogen migration, a detailed theoretical study of the production of CHClF, / 67, based on DFT calculations and natural bond orbital (NBO) analysis was conducted.
View Article and Find Full Text PDFShell-dependent photofragmentation dynamics of a heavy-atom-containing bifunctional nitroimidazole radiosensitizer.
Phys Chem Chem Phys
March 2024
Institute of Physics, University of Tartu, W. Ostwald 1, EST-50411, Tartu, Estonia.
Radiation therapy uses ionizing radiation to break chemical bonds in cancer cells, thereby causing DNA damage and leading to cell death. The therapeutic effectiveness can be further increased by making the tumor cells more sensitive to radiation. Here, we investigate the role of the initial halogen atom core hole on the photofragmentation dynamics of 2-bromo-5-iodo-4-nitroimidazole, a potential bifunctional radiosensitizer.
View Article and Find Full Text PDFA Metal-Free, Photocatalytic Method for Aerobic Alkane Iodination.
J Am Chem Soc
November 2021
Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, Pennsylvania 19104, United States.
Halogenation is an important alkane functionalization strategy, but O is widely considered the most desirable terminal oxidant. Here, the aerobic iodination of alkanes, including methane, was performed using catalytic [BuN]Cl and light irradiation (390 nm). Up to 10 turnovers of CHI were obtained from CH and air, using a stop-flow microtubing system.
View Article and Find Full Text PDFStructural Aspects of the Chloro- and Fluoro- Substituted Benzoic Acids: Implications on Chemical Properties.
Molecules
October 2020
Department of Chemistry, University of Coimbra, CQC, P 3004-535 Coimbra, Portugal.
This article presents a detailed comprehensive investigation of the fluoro- and chloro- substituted benzoic acids both, as isolated molecules and in the crystalline phase. Quantum chemical calculations performed within the density functional theory (DFT) formalism are used to investigate the potential energy landscapes of the molecules, taking into special consideration the effects of the interactions between the carboxylic group and the halogen substituents, as well as the nature of these later on the structure and properties of the investigated systems. The structures of the relevant conformers of the molecules are discussed in comparative terms, and used to rationalize experimental data obtained for the compounds in the gas phase and isolated in low-temperature inert matrices.
View Article and Find Full Text PDFVUV Photofragmentation of Chloroiodomethane: The Iso-CHI-Cl and Iso-CHCl-I Radical Cation Formation.
J Phys Chem A
September 2020
Institute of Structure of Matter-CNR (ISM-CNR), Area della Ricerca di Roma 1, Via Salaria km 29.300, 00015 Monterotondo, Italy.
Dihalomethanes XCHY (X and Y = F, Cl, Br, and I) are a class of compounds involved in several processes leading to the release of halogen atoms, ozone consumption, and aerosol particle formation. Neutral dihalomethanes have been largely studied, but chemical physics properties and processes involving their radical ions, like the pathways of their decomposition, have not been completely investigated. In this work the photodissociation dynamics of the ClCHI molecule has been explored in the photon energy range 9-21 eV using both VUV rare gas discharge lamps and synchrotron radiation.
View Article and Find Full Text PDF