Experimental and computational study of Polyyne and Cumulene chains interacting with carbon allotropes and metal nanoparticles.

The discovery of several carbon nanostructures and different allotropic phases has tremendously increased the interest towards pure carbon allotropes for their applications and for fundamental studies. Particularly interesting are the studies related to sp-hybridized carbon structures (polyynes and cumulenes) because they represent real one-dimensional conjugated systems and also because rings of polyyne chains are centrally important species for fullerene formation, emerging naturally under non-equilibrium conditions of hot carbon vapours. We will be able to give a contribution to the discussion on the literature on both the formation of sp-hybridized molecules and on the presence of appreciable amounts of cumulene species. Polyyne and cumulenes chains were produced by laser ablation in different solvents starting from graphite rods. Their interactions with others carbon allotropes and metal nanoparticles will be also investigated by means of DFT calculations; in particular we will analyze both structural and electronic modifications of the polyyne and cumulene chains induced by means of these interactions. Finally Raman and UV features analysis will be carried out in order to evaluate if such interactions allow to distinguish between polyynic and cumulenic structures.