An important new research area in the field of homogeneous catalysis is theuddevelopment of catalytic processes which combine the advantages of homogeneousud(high activity/selectivity, mild conditions, reproducibility, good catalyst description)udand heterogeneous catalysis (easy catalyst recycling, low catalyst quantities, highudtotal turnover number (ttn)). A promising approach to achieve this, is by applyingudnanofiltration technology: adjusted homogeneous catalysts are applied in a membraneudreactor and recycled in situ, even allowing catalytic reactions under continuouslyudoperating conditions. This leads to a significant increase in the total turnover numberudof the catalyst. Due to the very small pore-sizes in the membranes, macromoleculesudwith sizes between 0.5 and 8 nanometers can be retained in solution by applyingudnanofiltration technology. To create homogeneous catalysts which possess theuddimensions needed for efficient retainment by nanofiltration membranes, it isudnecessary to anchor catalytically active transition-metal complexes to solubleudmacromolecular supports.udThis thesis describes the design and synthesis of shape-persistent nanosizeudmulti(pincer-metal) complexes containing linear, flat or three-dimensionaludgeometries. In particular, these complexes were studied in a nanofiltration membraneudreactor in order to investigate the influences of shape-persistence, dimension andudgeometry on the retention of these compounds by nanofiltration membranes.udFurthermore, these macromolecular complexes were tested as homogeneous catalystsudin different organic transformations. One example is given in which a shape-persistentudnanosize complex is applied as a homogeneous catalyst in a nanofiltration membraneudreactor under continuous reaction conditions.udIn this research, aromatic supports were chosen for the macromolecularudcomplexes since it assures a high rigidity (shape-persistence) as well as a highudinertness toward many reagents, allowing a versatile use as homogeneous catalyst foruddiverse organic reactions. A further objective of this work was to investigate whetherudthese highly symmetric (C3- or D3-symmetry, as a result of the aromatic backbone andudthe substitution pattern) macromolecular materials could be used as supramolecularudtemplates in the selective construction of large heterocycles, using olefin metathesisudas the ring-closing reaction.
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