| The development of synthetic methods to construct discrete, rigid structures at the nanometer scale has to a large extent relied on metal-ligand coordination chemistry. Rational design and selection of precursors can lead to two- and three-dimensional supramolecular assemblies of predicted structure. These supramolecules feature unique structural precision on a molecular level and thus offer deliberate control over their macroscopic properties as desired features can be incorporated.;The long term goal of this project is the development of a surface-mounted, altitudinal (axle parallel to surface) molecular rotor using transition metal mediated, coordination driven self-assembly.;In this dissertation, a self-assembly path towards prismatic molecular rotors based on transversely reactive terminally metallated molecular rods and pyridine-terminated star connectors has been outlined. The concept was tested on the assembly of the biphenyl rod, [Ph2P(CH2) 3PPh2Pt+-C6H4-C 6H4-Pt+[Ph2P(CH2) 3PPh2], and 4,4'-bipyridyl into a molecular rectangle, fully characterized by NMR and MS, including diffusion-ordered NMR and collision-induced dissociation. The scope of the self-assembly path was then extended through the assembly of trigonal and tetragonal prisms from the biphenyl rod, [Ph2P(CH2)3PPh2Pt+-C 6H4-C6H4-Pt+[Ph 2P(CH2)3PPh2], and the star-shaped connectors, 1,3,5-tris-(4-ethynylpyridyl)benzene and [tetrakis(4-pyridyl)cyclobutadiene]cyclopentadienylcobalt, respectively. The structures were established by NMR and MS, including diffusion-ordered NMR and collision-induced dissociation, and their chiral structures optimized by molecular mechanics are discussed. Incorporation of paddlewheels into the prisms was accomplished by self-assembly of rods based on 9,10-diethynyltriptycene terminated in transversely reactive [Pt(dppp)]+ groups (dppp = 1,3-bis(diphenylphosphino)propane), and the connector, 1,3,5-tris[(4-pyridyl)ethynyl]benzene. The structures were established by NMR and MS, including diffusion-ordered NMR and collision-induced dissociation.;Attempts were made to modify the assemblies to yield neutral species through transmetallation reactions.;Finally, three-dimensional discrete trigonal prisms are presented which allowed the study of the dynamic nature of the Pt-pyridine bond. This experiment probes the kinetic stability of the assemblies. |
