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Società Chimica Italiana Prizes 2014

Annual fiber sorghum (FS) and perennial giant reed (GR) cultivated in the Mediterranean area are interesting due to their high productivity under drought conditions and their potential use as lignocellulosic feedstock for biorefinery purposes. This study compares environmental constraints related to FS and GR produced on experimental farms (in the Campania region) using an attributional life cycle assessment (LCA) approach through appropriate modeling of the perennial cultivation. For both crops, primary data were available for agricultural management. Direct field emissions (DFEs) were computed, including the potential soil carbon storage (SCS). Giant reed showed the lowest burdens for all impact categories analyzed (most were in the range of 40%-80% of FS values). More apparent were the differences for climate change and freshwater eutrophication (respectively 80% and 81% lower for GR compared to FS). These results are due to the short-term SCS, experimentally detected in the perennial GR crop (about 0.25 ton C ha(-1) yr(-1), with a global warming offsetting potential of about 0.03 ton CO2/ton(GR dry biomass)). The results are also due to the annual application of triple superphosphate at the sowing fertilization phase for FS, which occurs differently than it does for GR. Phosphorous fertilization was performed only when crops were being established and therefore properly spread along the overall crop lifetime. For both crops, after normalization, terrestrial acidification and particulate matter formation were relevant impact categories, as a consequence of the NH3 DFE by volatilization after urea were spread superficially. Therefore, the results suggest higher environmental benefits of the perennial crop than the annual crop.

Dye-sensitized solar cells (DSC) recently attracted much attention as promising devices for the conversion of sunlight in electric power.[1] Such cells employ dyes, which act as photosensitizers, together with a suitable inorganic semiconductor, such as TiO2. Historically, the first class of photosensitizers employed in DSC was represented by transition metal complexes, such as the Ru-bipyridyl complex N719.[2] More recently, purely organic sensitizers, not containing any metal atom, have emerged as a cheap and efficient alternative.[3] Such substances are often based on a "donor-?-acceptor" architecture, featuring electron-donating and electron-accepting groups separated by a conjugated spacer. Here, we will present some of the dyes recently prepared in our laboratories, whose general structure (1) is shown in the figure. The synthesis of these compounds will be described together with the results of preliminary experiments conducted on test cells containing the novel sensitizers. [1] Hagfeldt, A.; Boschloo, G.; Sun, L.; Kloo, L.; Pettersson, H. Chem. Rev. 2010, 110, 6595. [2] (a) O'Regan, B.; Grätzel, M. Nature 1991, 353, 737 [3] (a) Mishra, A.; Fisher, M. K. R.; Bäuerle, P. Angew. Chem. Int. Ed. 2009, 48, 2474. (b) Ooyama, Y.; Harima, Y. Eur. J. Org. Chem. 2009, 2903.