Repositori URV

Identificador: TDX:877

Handle: https://hdl.handle.net/20.500.11797/TDX877

Autors:
Romo del Amo, Susana

Resum:
The doctoral thesis consists of eight chapters. The first chapter contains an overview of the theories on the structures are more typical of polioxometalat and the general characteristics of these complexes. The second chapter presents the computational methods that are based on extensive research and theory that is based on the methodologies used. The first results (Chapter 3) iare presented on a previous study comparing different computational methods with the smallest structures that exist as polyoxoanions, the Lindqvist anions, M6O19n-. The second results chapter (Chapter 4), has reproduced the spectrum of electronic polioxometalat containing a paramagnetic metal in Anderson structures, XM6O24, using various computational methods. In the fifth chapter is the study conducted semiquantitative electrochemical properties of the sandwich type polyoxometalats with more than a paramagnetic metal in its structure, in which the reduction occurs selectively. Verified the position where the first reduction in this anion, as well as the fundamental species of oxidized and reduced. Could play with relative accuracy the electrochemical presented and how these anions in the pH of the reduction process. The sixth chapter is the largest, have been studied extensively the properties of a POM when it contains an atom of Tc. First is a comprehensive discussion of the structures Lindqvist, M6O19, which is taken as a model to be expanded later with the structures of Wells-Dawson. These are ideal candidates for the immobilization of ion Tc (99Tc) that occurs as a radioactive waste at nuclear power plants. Then, the study has been extended to transition metal of groups 6-9 where there has been a general trend in the redox properties and the basicity that produce the substituted metal. Afte