New Method for Double-Resonance Spectroscopy in a Cold Quadrupole Ion Trap and Its Application to UV-UV Hole-Burning Spectroscopy of Protonated Adenine Dimer.
A novel method for double-resonance spectroscopy in a cold quadrupole ion trap is presented, which utilizes dipolar resonant excitation of fragment ions in the quadrupole ion trap. Photofragments by a burn laser are removed by applying an auxiliary RF to the trap, and a probe laser detects the depletion of photofragments by the burn laser. By scanning the wavelength of the burn laser, conformation-specific UV spectrum of a cold ion is obtained. This simple and powerful method is applicable to any type of double-resonance spectroscopy in a cold quadrupole ion trap and was applied to UV-UV hole-burning spectroscopy of protonated adenine dimer. It was found that protonated adenine dimer has multiple conformers/tautomers, each with multiple excited states with drastically different excited state dynamics.
†Department of Chemistry, Ajou University, San5, Wonchon-dong, Youngtong-gu, Suwon 443-749, Korea.
Hyuk
H
Kang
‡CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaire (PIIM) UMR 7345, 13397 Marseille Cedex, France.
Géraldine
G
Féraud
‡CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaire (PIIM) UMR 7345, 13397 Marseille Cedex, France.
Claude
C
Dedonder-Lardeux
‡CNRS, Aix-Marseille Université, Physique des Interactions Ioniques et Moléculaire (PIIM) UMR 7345, 13397 Marseille Cedex, France.
Christophe
C
Jouvet
UV−UV hole-burning; biomolecular ion; cold ion spectroscopy; double-resonance; quadrupole ion trap