Tesis doctoral de Laura Gómez Martín
The high efficiency, selectivity and mild conditions exhibited by the reactions that take place in the active site of metallooxygenases are the source of inspiration of the present dissertation. With the aim of designing efficient oxidation catalysts, in this thesis we make use of two different strategies: the first one is the design of low molecular weight complexes inspired by structural aspects of the first coordination sphere of the metal active site of non-heme iron and manganese enzymes. These complexes are studied as catalysts for the selective oxidation of alkanes and alkenes using green oxidants such as h2o2 (or peracetic acid). The second strategy is based on the use of supramolecular chemistry to develop self-assembled molecular structures with desired shape and chemical properties. Particularly, the construction of cavity-containing 3d nanovessels with an oxidation catalyst embedded in their structures would allow us to perform more selective reactions, analogously to the reactions taking place in the active site of enzymes. in the first part (chapter iii an iv), we describe the introduction of sterically bulky pinene groups at the 4th-5th position of the pyridine rings of a series of nitrogen based tetradentate ligands. The corresponding mononuclear iron(ii) complexes are prepared, spectroscopically and structurally characterized, and studied in catalytic alkane and alkene oxidation reactions. The sterically bulky catalysts are more efficient in the oxidation of alkanes than their homologues lacking the steric pinene groups (chapter iii). The electrodonating properties of the pinene groups along with the steric protection that they confer to the metal centre are suggested to be responsible for the increase in the activity by stabilizing species implicated in the catalysis. in the chapter iv, two mononuclear manganese(ii) complexes derived from the aforementioned ligands are employed as stereoselective epoxidation catalysts. the second part of the dissertation (chapter v and vi) starts with the development of control parameters for the formation of 2d self-assembled molecular structures (rectangles and helicates) with the desired shape (chapter v). Three levels of molecular control are studied. Evolution of the system to a 3d nanovessel with catalytic properties is developed in chapter vi. Finally, the performance and selectivity of this system in alkene epoxidation is studied.
Datos académicos de la tesis doctoral «Bioinspired iron and manganese catalysts for the effective and selective oxidation of alkanes and alkenes«
- Título de la tesis: Bioinspired iron and manganese catalysts for the effective and selective oxidation of alkanes and alkenes
- Autor: Laura Gómez Martín
- Universidad: Girona
- Fecha de lectura de la tesis: 04/06/2010
Dirección y tribunal
- Director de la tesis
- Xavier Ribas Salamaña
- Tribunal
- Presidente del tribunal: robertus j. m. Klein gebbink
- Mª del mar Díaz requejo (vocal)
- david brian Amabilino (vocal)
- ronald Hage (vocal)