Photoelectron Spectra and Electronic Structures of the Radiosensitizer Nimorazole and Related Compounds.
Soft X-ray photoelectron spectroscopy has been used to investigate the radiosensitizer nimorazole and related model compounds. We report the valence and C, N, and O 1s photoemission spectra and K-edge NEXAFS spectra of gas-phase nimorazole, 1-methyl-5-nitroimidazole, and 4(5)-nitroimidazole in combination with theoretical calculations. The valence band and core level spectra are in agreement with theory. We determine the equilibrium populations of the two tautomers in 4(5)-nitroimidazole and find a ratio of 1:0.7 at 390 K. The NEXAFS spectra of the studied nitroimidazoles show excellent agreement with spectra of compounds available in the literature that exhibit a similar chemical environment. By comparing 1-methyl-5-nitroimidazole (single tautomer) with 4(5)-nitroimidazole, we are able to disentangle the photoemission and photoabsorption spectra and identify features due to each single tautomer.
School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , 30 Flemington Road, 3010 Parkville, Victoria, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology , Parkville, Victoria 3010, Australia.|Institut de Physique Nucléaire de Lyon, Université Claude Bernard Lyon1, Université de Lyon, CNRS/IN2P3 UMR 5822 , 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France.
Linda
L
Feketeová
Elettra-Sincrotrone Trieste , in Area Science Park, 34149 Basovizza, Trieste, Italy.
Oksana
O
Plekan
Molecular Model Discovery Laboratory, Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , 3122 Hawthorn, Victoria, Australia.
Mayanthi
M
Goonewardane
Molecular Model Discovery Laboratory, Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , 3122 Hawthorn, Victoria, Australia.
Marawan
M
Ahmed
School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , 30 Flemington Road, 3010 Parkville, Victoria, Australia.
Abigail L
AL
Albright
School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , 30 Flemington Road, 3010 Parkville, Victoria, Australia.
Jonathan
J
White
School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne , 30 Flemington Road, 3010 Parkville, Victoria, Australia.|ARC Centre of Excellence for Free Radical Chemistry and Biotechnology , Parkville, Victoria 3010, Australia.
Richard A J
RA
O'Hair
Department of Experimental Clinical Oncology, Aarhus University Hospital , Nørrebrogade 44, 8000 Aarhus C, Denmark.
Michael R
MR
Horsman
Molecular Model Discovery Laboratory, Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , 3122 Hawthorn, Victoria, Australia.
Feng
F
Wang
Elettra-Sincrotrone Trieste , in Area Science Park, 34149 Basovizza, Trieste, Italy.|Molecular Model Discovery Laboratory, Department of Chemistry and Biotechnology, Faculty of Science, Engineering and Technology, Swinburne University of Technology , 3122 Hawthorn, Victoria, Australia.
Kevin C
KC
Prince
D008958:Models, Molecular; D008962:Models, Theoretical; D015394:Molecular Structure; D009554:Nimorazole / Q000737:chemistry*; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011838:Radiation-Sensitizing Agents / Q000737:chemistry*
D011838:Radiation-Sensitizing Agents; D009554:Nimorazole