CEFITEC exploratory project recommended for FCT funding

Researcher Mónica Mendes, from the Atomic and Molecular Collisions group of CEFITEC, had her project approved for funding in the FCT Contest for Exploratory Projects in All Scientific Domains 2023.

Project title: Electron-induced chemistry in space: a first step towards insight into extraterrestrial environments? Fundamental gas phase studies

Abstract:

The interstellar medium (ISM) is the region between the stars, that appears dark since the present gas and dust absorb the light from the stars. Astronomic observations have reported more than 300 molecules and ions present in ISM, including organic molecules such as benzene, glycolaldehyde, or even chiral molecules. From these observations, the ISM is considered as a rich depository of prebiotic molecules, which from stars and planets are formed. The possibility of molecular life building blocks could be formed in space is intriguing, since ISM is an unlikely place for development chemistry. The low temperature and low pressure make the ISM as a “cold” and “empty” for a reaction rate fast enough to develop such high complex molecules. Nevertheless, the detection of such molecules in the ISM, increasing in number and complexity, makes clear that ISM is a chemical active zone. One possible explanation for this paradox, is that the observed chemistry is somehow different from the chemistry observed in the Earth, being induced by radiation. There are several different sources of radiation in the ISM, namely UV radiation, cosmic rays, gamma- and X-rays. All these sources of radiation can thermalize producing slow electrons, as secondary species, along radiation track.

The present research project intends to shine light on the low energy electron driven reactions on selected compounds detected in the interstellar medium in order to understand and describe chemistry driven by electrons and astrochemical relevant molecules, in the gas phase. The chosen molecular targets are benzonitrile and two cyano naphthalenes isomers (Fig. 1). Cyano ions have been proposed to participate in chemical reactions in the ISM, initiated by radiation. Another approach is to investigate the electron induced chemistry in the first observed chiral molecule in the ISM, propylene oxide (Fig. 1). Electron ionization and dissociative electron attachment studies will be performed to describe the fragmentation pattern in positive and negative ion formation, as well as characterizing the thermochemistry involved in these processes. Moreover, XPS (X-ray photoelectron spectroscopy) studies on films of the target compounds will be performed to further characterize the chemical modification by X-ray and electron irradiation. Additionally, theoretical quantum chemical calculations will be implemented for characterizing the negative and positive ion formation.

From the ELEICS research project is expected to draw new ideas and chemical reactions for a better description of low-energy electrons induced chemistry in the ISM. The research team has demonstrated knowledge on the different experimental and theoretical proposed approaches. This complementarity together with the scientific capacity, ensures to achieve the proposed objectives and bringing results essential for bridging fundamental to applied research.