skip to main content

Title: Vacuum ultraviolet photoionization of carbohydrates and nucleotides

Carbohydrates (2-deoxyribose, ribose, and xylose) and nucleotides (adenosine-, cytidine-, guanosine-, and uridine-5{sup ′}-monophosphate) are generated in the gas phase, and ionized with vacuum ultraviolet photons (VUV, 118.2 nm). The observed time of flight mass spectra of the carbohydrate fragmentation are similar to those observed [J.-W. Shin, F. Dong, M. Grisham, J. J. Rocca, and E. R. Bernstein, Chem. Phys. Lett. 506, 161 (2011)] for 46.9 nm photon ionization, but with more intensity in higher mass fragment ions. The tendency of carbohydrate ions to fragment extensively following ionization seemingly suggests that nucleic acids might undergo radiation damage as a result of carbohydrate, rather than nucleobase fragmentation. VUV photoionization of nucleotides (monophosphate-carbohydrate-nucleobase), however, shows that the carbohydrate-nucleobase bond is the primary fragmentation site for these species. Density functional theory (DFT) calculations indicate that the removed carbohydrate electrons by the 118.2 nm photons are associated with endocyclic C–C and C–O ring centered orbitals: loss of electron density in the ring bonds of the nascent ion can thus account for the observed fragmentation patterns following carbohydrate ionization. DFT calculations also indicate that electrons removed from nucleotides under these same conditions are associated with orbitals involved with the nucleobase-saccharide linkage electron density. The calculations give a generalmore » mechanism and explanation of the experimental results.« less
Authors:
 [1] ;  [2] ;  [3]
  1. Division of Science, Governors State University, University Park, Illinois 60484-0975 (United States)
  2. (United States)
  3. Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523-1872 (United States)
Publication Date:
OSTI Identifier:
22255181
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 140; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; ADENOSINE; CYTIDINE; DENSITY FUNCTIONAL METHOD; DEOXYRIBOSE; ELECTRON DENSITY; ELECTRONS; FRAGMENTATION; GUANOSINE; IONS; MASS SPECTRA; NUCLEIC ACIDS; PHOTOIONIZATION; PHOTONS; RIBOSE; URIDINE; XYLOSE