Photofragmentation of a perfluorocarboxylic acid using synchrotron radiation: Study of CF3CF2C(O)OH

YANINA BERRUETA MARTÍNEZ; YANINA B. BAVA; REINALDO L. CAVASSO FILHO; CARLOS O. DELLA VÉDOVA; ROSANA M. ROMANO

Campinas

Otro; 25th RAU Annual Users Meeting LNLS; 2015

Laboratório Nacional de Luz Síncrotron

Perfluorinated compounds have been extensively used in industrial applications during the last years. Recently, some perfluorinated species were detected in tissues of animals, in environmental waters, and in the atmosphere.[1,2] Different processes may be responsible for the presence of these compounds in the environment. For example, the thermolysis of fluoropolymers and the degradation of fluorotelomer alcohols result in the emission of perfluorocarboxylic species to the atmosphere. In this work, and as part of a general project aimed to the elucidation of the photofragmentation mechanisms of compounds relevant for atmospheric chemistry, we present the study of perfluoropropionic acid using synchrotron radiation with energies between 7.3 and 300eV. The photoexcitation and photofragmentationof this species was studied in the TGM beamline at LNLS. Above 11.7 eV different ions can be observed in the PEPICO spectra. At exactly 11.7 eV, COH+, C2F4+, and M+ were detected. This result shows that the cleavage of two covalent bonds is carried out at energies barely higher than the first ionization potential. The peak corresponding to C(O)OH+ was detected at 11.8 eV, and CF3CF2+ appeared in the spectra from 15 eV. The parent ion was only detected below 16 eV. From that energy, the heaviest ion observed in the PEPICO spectra was the M-OH+ fragment. Unlike the fragments observed in the previously studied analogous molecule CF3CF2CF2C(O)Cl,[3] CF+, CF2+, and CF3+ ions were not the most abundant peaks in the spectra.