A study about dimers formation of formic acid in gas phase and in the valence region

Full text: Study of simple pre-biotic molecules takes great importance for understanding about complex organic molecules formation like amino acids, proteins and nucleobases within the DNA and RNA. A hypothesis for the appearance of nucleobases is that they could have been synthesized from simpler organic composites contained in interstellar medium (ISM), meteorites and asteroids. Lots of experiments have demonstrated that it is possible to produce complex pre-biotic molecules from simpler molecules under environments that simulate the ISM. Thus, we have performed a theoretical and experimental study about photoionization and photofragmentation processes of simple pre-biotic molecules that are important in the synthesis of complex biomolecules. In this work particularly, we performed photoionization and photofragmentation process of formic acid-D2 (CDOOD) in order to verify if some molecular fragmentations coming from dimers that could be formed before ionization region at TOF mass spectrometer. Experimentally, we measured these molecules mass spectra in gaseous phase. These spectra were got as function of pressures in experimental chamber, temperature samples and photon energy, in the vacuum ultraviolet region, between 11 and 20 eV. These data had been obtained in the Brazilian Laboratory of Synchrotron Light, by using mass spectrometer of flight time. The mass spectra had been obtained by using the photoelectron photoion coincidence technique, PEPICO. For a better understanding of experimental results, we have made a theoretical analysis of the photofragmentation by using Density Functional Theory. (author)