4 resultados para excess phosphorus

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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The chief obstacle to understand the metabolic origin of life or RNA-based life is to identify a plausible mechanism for overcoming the clutter wrought by abiotic chemistry. Probably trough simple abiotic and then prebiotic reactions we could arrive to simple pre-RNA molecules. Here we report a possible preibiotic synthesis for heterocyclic compounds, and a self-assembling process of adenosine phosphates a constituent of RNA. In these processes we use a simple and prebiotic phosphorus cyclic compounds, as P4O10 and its derivatives. The processes are driven by the formation of hypercoordinated species that activate the processes by a factor of 106-8.

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Copper(I) halide clusters are recently considered as good candidate for optoelectronic devices such as OLEDs . Although the copper halide clusters, in particular copper iodide, are very well known since the beginning of the 20th century, only in the late ‘70s the interest on these compounds grew dramatically due their particular photophysical behaviour. These complexes are characterized by a dual triplet emission bands, named Cluster Centred (3CC) and Halogen-to-Ligand charge transfer (3XLCT), the intensities of which are strictly related with the temperature. The CC transition, due to the presence of a metallophylic interactions, is prevalent at ambient temperature while the XLCT transition, located preferentially on the ligand part, became more prominent at low temperature. Since these pioneering works, it was easy to understand the photophysical properties of this compounds became more interesting in solid-state respect to solution with an improvement in emission efficiency. In this work we aim to characterize in SS organocopper(I)iodide compounds to valuate the correlation between the molecular crystal structure and the photophysical properties. It is also considered to hike new strategies to synthesize CuI complexes from the wet reactions to the more green solvent free methods. The advantages in using these strategies are evident but, obtain a single crystal suitable for SCXRD analysis from these batches is quite impossible. The structure solution still remains the key point in this research so we tackle this problem solving the structure by X-ray powder diffraction data. When the sample was fully characterized we moved to design and development of the associated OLED-device. Since copper iodide complexes are often insoluble in organic solvents, the high vacuum deposition technique is preferred. A new non-conventional deposition process have also been proposed to avoid the low complex stability in this practice with an in-situ complex formation in a layer-by layer deposition route.

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The idea of the tragic is unthinkable. It is precisely within the moment in which an ordinary human being, a heroine or a hero – incapable of scrutinizing fully their own position within the whole – is invited to respond, to accept or refuse it all, that the tragic unfolds, changing their life irremediably. What are the causes and the consequences of "god’s arrival", as in case of Dionysus who visits Pentheus’ home in Euripides’ "The Bacchae"? Through episodes in the stories of characters from Ancient Greek dramas – such as Oedipus, Antigone, Ajax, Io, through Dostoevsky’s or Kafka’s imagery, in Prince Myshkin’s, the Ridiculous Man’s or Gregor Samsa’s experiences, this doctoral research proposes to examine the aspects which compete in the creation of a tragic hero. Theatrical performances – such as Jan Fabre’s "Mount Olympus: To Glorify the Cult of Tragedy, a 24-Hour Performance", immersed in a cycle of life, death and re-birth; Oliver Frljić’s "Trilogija o hrvatskom fašizmu", in its careful analysis of the wounds of a heritage of war; and Cristian Ceresoli’s and Silvia Gallerano’s tragic testimony of an estranged, almost soulless body in "La Merda" – open up the dialogue on our contemporary idea of the tragic. This doctoral work chooses excess as its privileged channel through which to approach the concept of the tragic – by its nature elusive, hostile to any definition, strictly personal and, thus, visible only through one’s own lens. In an excess of pain, devotion, desire, rage, arrogance or beauty, opposites collide, time concentrates into a moment and the hero is invited to choose, to live or die, to transform.