IR-UV double resonance spectroscopy of xanthine.
We present resonant two-photon ionization (R2PI), UV-UV, and IR-UV double resonance spectra of xanthine seeded in a supersonic jet by laser desorption. We show that there is only one tautomer of xanthine which absorbs in the wavelength range of 36 700 to 37 700 cm(-1). The IR-UV double resonance spectrum shows three strong bands at 3444, 3485, and 3501 cm(-1), all of which we assign as N-H stretching vibrations. Comparison of the IR-UV double resonance spectrum with frequencies and intensities obtained from density functional theory (DFT) and second order Møller Plesset (MP2) calculations suggests that the observed xanthine is the diketo N(7)H tautomer.
Callahan
Michael P
MP
Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106-9510, USA.
Crews
Bridgit
B
Abo-Riziq
Ali
A
Grace
Louis
L
de Vries
Mattanjah S
MS
Gengeliczki
Zsolt
Z
Holmes
Tiffani M
TM
Hill
Glake A
GA
D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D019820:Xanthine / Q000737:chemistry*
D019820:Xanthine