Synthesis of polymeric membranes with nanoscale porosity and characterization of precursors by high angle molecular diffraction

The design and synthesis of molecular materials with nanoscale porosity has been a major component of contemporary coordination chemistry. Within the field many fundamental and applied questions about the structure and function of these materials still exist. This thesis describes efforts toward answering two questions about these materials.; First, the synthesis and fabrication of porphyrinic polymer membranes with nanoscale porosity is discussed. Porphyrinic molecular squares and sterically hindered porphyrins have been bound together to form polymeric films with nanoscale porosity. Characterization of these materials with respect to structure and molecular sieving capability is detailed. Also included is research directed at improvement of materials properties by physical and chemical alteration of the films. Additionally, inclusion of functional substituents with the goal of fabricating membranes with biomimetic properties such as gated transport and catalytic activity is addressed.; The second portion of the thesis deals with the fundamental characterization of molecular square and other polyhedral complexes by a newly developed structural technique, solution phase high angle molecular diffraction. High angle molecular diffraction is an extension of small angle X-ray scattering, which has been demonstrated to be powerful in the structural characterization of proteins and other macromolecules. While in the small angle experiments, the majority of the data obtained tells about overall structure and size of the molecule under consideration, in the high angle technique, scattering data is collected for a concentrated solution to resolutions as high as one angstrom, and the pair distance distribution function is used to obtain real space structure and dynamics of supramolecules in a solution phase environment. Using this technique, the structure and dynamics of Re-bridged molecular squares, triangles, rectangles, host-guest assemblies, and prisms have been studied extensively in order to better understand the structural characteristics of these supramolecules in solution.