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| Author(s): |
Sofia Nikolaou
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Conjunto das Químicas (IQ e FCF) (CQ/DBDCQ) |
| Defense date: | 2002-04-23 |
| Examining board members: |
Henrique Eisi Toma;
Alzir Azevedo Batista;
Neyde Yukie Murakami Iha;
Luíz Antônio Andrade de Oliveira;
Denise de Oliveira Silva
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| Advisor: | Henrique Eisi Toma |
| Abstract | |
The aim of the work reported is to develop polynuclear structures based on trinuclear ruthenium clusters. All the oligomers are seen as interesting options to the future development of supramolecular devices, due to their photophysical and electrochemical properties. A series of mixed dimers and one trimer were obtained by the combination of the [Ru3O(CH3COO)6(py)2(CH3OH)]+ cluster with [Ru(bpy)2(P)(L)]+ complexes (P = N-heterocyclic bridging ligand; L = P, Cl or CN). The NMR, cyclic voltammetry and spectroelectrochemical characterization of the dimers where L = Cl were used as a base to interpret the results collected for the other complexes; the data reflect a weak interaction between the units, depending on the electronic characteristics of the bridging ligand P. In the dimers where L = CN, occurs the quenching of the [Ru(bpy)2] emission by the cluster through a photoinduced electron transfer mechanism. For the cluster in its reduced form, it is suggested that an energy transfer process also occurs. On the second part of the Thesis, polycluster systems containing six and ten bridged cluster units are reported. The novel supermolecules present a series of multielectronic redox processes and, in this case, electronic communication among the metallic centers is more pronounced, depending on the clusters oxidation state. (AU) | |