Research interests of Prof. Franco Gianturco
1. Radiation Damage
One of the basic questions which has come up from the earliest stages of the study on the effects of the electromagnetic field on biological material, and on the living organisms, has been that of pinning down the way in which the ensuing radiation can alter, damage or kill the target organisms. Only very recently, however, it has become apparent, although not yet fully explained, that the emission of secondary electrons at energies below ionization thresholds is one of the most efficient (and lethal!) sources of damage to biomaterials.
The consensus which is beginning to build up, in fact, suggests that such fast electrons, before and in competition with undergoing solvation into the aqueous medium, are able to form a variety of Transient Negative Ions (TNIs) which in turn allow efficient excess energy deposition into the molecular bonding network, a feature which causes dissociative electron attachment into a broad variety of negative fragments:
M(v,j) + c- -> (TNI) -> Ma(v'j') +Mb-(v'',j')
2. Astrochemistry
- The formation of increasingly larger Polycondensed Aromatic Hydrocarbons (PAHs) starting with the most likely molecular cornerstones like the benzene and benzyne, molecules which are suspected of forming metastable anionic states leading to ring-opening reactions;
- A further class of compounds that are also connected with the formation of metastable and possibly stable anions are the linear carbon chains terminated by either H or N, that have been recently observed in the Interstellar medium: C6H- , C4H-, C8H-, NC4N-, etc. They are all object of analysis and simulation in our group in order to isolate the most likely paths leading electron attachment and ensuing energy redistribution via molecular fragmentations;
- The study of exothermic reactions in the early Universe, and the role played by the chemistry of Lithium-containing species, is also one of the topics regarding the Chemical Cosmos which are pursued by the group. A further topic of studies in the realm of reactive events is also the analysis of ionic reactions containing He and/or H in order to establish possible preferential evolutionary paths leading to the survival of specific ionic compounds amenable to observation.
3. Helium Nanodroplets
4. Ultracold Chemistry
This has meant that the theoreticians interested in this area had to meet the challenges that this new class of experiments have provided and also had to develop, or to retool, some of the necessary machinery to study many of the processes involved.
Examples for this are: the collisional energy transfer processes down to the Wigner regime, the presence of chemical reactions at vanishing collision energies, the role of virtual states on both types of processes and the analysis of Feshbach resonances and of Efimov States.
5. Lepton Chemistry
or through annihilation processes: M(v,j) + e+ → M+ (v,j) + 2γ
Both the above elementary mechanisms pose great challenges to theorists since one needs to unravel the actual nanoscopic dynamics of the processes, the efficiency of which changes greatly from molecule to molecule.