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Self-assembly of two- and three-dimensional palladium(II) and platinum(II) macrocyclic complexes

Posted on:2000-02-03Degree:Ph.DType:Thesis
University:The University of UtahCandidate:Fan, JunFull Text:PDF
GTID:2461390014464647Subject:Chemistry
Abstract/Summary:
The rational design, effective synthesis and total characterization of self-assembled, two- and three-dimensional, supramolecular macrocyclic structures are presented in this dissertation. The strategy used for the design of molecular polygons and polyhedra exploited the highly directional coordination between the transition metals (Pd, Pt) and nitrogen based organic ligands. The size, shape, and functionality of the final products were determined by the preprogrammed building blocks, from which the assemblies were formed.; Molecular squares were assembled by reacting square planar, cis-ditopic Pd(II) or Pt(II) complexes with linear or 90° corner subunits. Ferrocene was incorporated into these systems through attachment to the transition metal bisphosphines. Porphyrins containing two 4-pyridyl moieties could serve as both linear linkers (trans-) and 90° angular units (cis-) to afford squares with the potential for light-harvesting and photon/energy transfer. Introducing highly polar functional groups into the macrocycles based on the combination of organophosphine and transition metals provided them good solubility in water, which gave these systems possible applications in heterogeneous catalysis. In addition, chirality in these systems was achieved via chiral building blocks or induced by the unique orientation of subunits in the assembly itself.; Molecular pentagons were obtained by the combination of pre-designed 108° corners and linear linkers. Three-dimensional cage compounds, including molecular octahedra, adamantanoids, and boxes, were also synthesized by self-assembly via coordination.; The preparation of self-assemblies was generally straightforward and leads to quantitative yields, although the synthesis of precursors could be difficult. Most of the assemblies were robust solids that have been characterized by various analytical and spectroscopic methods: multinuclear NMR spectra, IR, UV-Vis, CD/ORD, elemental analyses (EA), melting points, mass spectrometry (MS), and X-ray crystallography. The NMR spectra, especially the 31 P{lcub}1H{rcub} NMR spectra established the high symmetry of these macrocyclic systems; EA and MS determined the composition of these complexes; and X-ray crystal analysis provided their absolute structure in the solid state. Furthermore, IR, UV-Vis, and CD/ORD revealed their unique optical properties. Host-guest interactions were also investigated for some of these systems.
Keywords/Search Tags:Three-dimensional, Macrocyclic, NMR spectra, Systems, Molecular
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