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Functionalized organogold(I) complexes from base -promoted auration, copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition and Horner-Wadsworth-Emmons reactions and metallo-azadipyrromethene complexes for solar energy conversion and oxygen evolution

Posted on:2011-10-20Degree:Ph.DType:Thesis
University:Case Western Reserve UniversityCandidate:Gao, LeiFull Text:PDF
GTID:2441390002468526Subject:Chemistry
Abstract/Summary:
Functionalized organogold(I) complexes were synthesized from base-promoted auration, copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition and Horner-Wadsworth-Emmons reactions. The base-promoted auration process provides a mild and convenient way to generate Au--C bonds. Cu(I)-catalyzed cycloaddition produces 1,4-regiomeric products from benzyl azide and gold(I) internal alkynyls. The heavy atom effect of gold promotes the intersystem crossing. Triplet state emission is observed at room temperature for compounds with polycyclic substituents. These synthetic methods combined with modified Horner-Wadsworth-Emmons reactions produced two-photon absorbing gold(I) distyryl benzene and naphthalene complexes. These compounds are strongly emissive, and the heavy atom effect of gold in potentiating the singlet oxygen generation is expected. Their two-photon absorption cross sections will be measured and compared. The optimal position of gold(I) installation, the number of gold(I) substituents and the geometry of the compound will be associated with their two-photon absorption cross sections and singlet oxygen generation efficiencies.;Gold(I) and gold(III) azadipyrromethene complexes were synthesized for solar energy conversion. Phosphinegold(I) azadipyrromethene complexes were synthesized and characterized. Synthesis of Au(III) complexes was attempted by reacting the azadipyrromethene ligands with Au(III) starting materials and directly reacting the phosphinegold(I) azadipyrromethene complexes with liquid bromine.;A tetradentate azadipyrromethene ligand was prepared and used to synthesize oxygen evolving metalloazadipyrromethene complexes. A zinc complex was synthesized to establish the structural and spectroscopic consequences of metal binding. The absorption profile of the ligand carries over upon metalation. Weak emission is observed in the zinc complex. The binding geometry of the zinc centers confirms that the ligand can provide four coordination sites. A vanadyl complex was synthesized to study the compatibility of the ligand with metal oxos. The intact structure of the ligand upon binding to vanadyl proves that the ligand can support metal oxos without being oxidized. Afterwards, the reduced form of oxygen-evolving manganese and iron complexes were synthesized. Their oxos will be produced by reacting with oxygen-atom donors. The produced metal oxos will react with water, OH- as well as OCl- to generate oxygen.
Keywords/Search Tags:Complexes, Gold, Horner-wadsworth-emmons reactions, Oxygen, Metal, Cycloaddition, Auration, -catalyzed
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