Infrared Multiple Photon Dissociation Spectroscopy of Protonated Cyameluric Acid

W. OLMEDO; A. CRUZ ORTIZ; L. JIMENEZ; P. MAITRE; G. A. PINO; M. ROSSA

JOURNAL OF PHYSICAL CHEMISTRY A

AMER CHEMICAL SOC

Lugar: Washington; Año: 2021 vol. 125 p. 607 - 607

1089-5639

he infrared multiple photon dissociation (IRMPD) technique was used to probe the structure of gaseous protonated cyameluric acid [(CA+H)+], as produced under tandem mass spectrometry (MS/MS) conditions through electrospray ionization (ESI). IRMPD is most suitable to investigate the diversity of keto-enol isomerism of (CA+H)+, as arising from a number of precursor CA tautomers present under ESI-MS/MS conditions, and the various protonation sites on available N and O positions for any particular CA tautomer. Experimental IRMPD spectra in the fingerprint (990-1900 cm1) and NH/OH stretching (3300-3650 cm1) regions were recorded at the Centre Laser Infrarouge d´Orsay using the free-electron laser and a tabletop optical parametric oscillator/amplifier laser system, respectively. These were compared with the theoretical [B3LYP/6-311++G(d,p)] IR absorption spectra of a number of planar (CA+H)+ isomers, and it was found that the agreement is most satisfactory fo