Student Project Abstracts 2005 - Pluto - University of Washington

Synthesis of Norbornene Monomer of PPV-C 60Dyads (TDC-I-056)Taína D. ClevelandGeorgia Institute of TechnologyDr. Jian-Yang Cho (JD) and Dr. Seth MarderSchool of Chemistry & BiochemistryGeorgia Institute of TechnologyINTRODUCTIONAs the need for a renewable, clean energy source is expanding,a promising technology based on organic or polymeric materialsmay offer a lightweight, flexible, cost-effective renewablesolar energy solution. 1 Conducting polymers like PPV (poly(1,4-phenylenevinylene)) functioning as donors and C 60derivatives asacceptors have been widely used for photovoltaic cell applications.However, composite films made by mixing PPV and C 60usually leads to phase separation because C 60tends to form crystals which makes the donor and acceptor molecules incompatiblein composite films. It results in poor homogeneity and low opticalquality of the films leading to inefficient intramolecular andintermolecular energy or electron transfer in solar cells.OBJECTIVE OF THE RESEARCH PLANThe objective of this investigation is to synthesize polymericmaterials where donors and acceptors are covalently linked topolymer backbone, which presumably can avoid phase separationproblems. In addition, these polymeric materials can be dissolvedin common organic solvents, “wet” methods such as spin coatingcan be used for device fabrication.Most PPVs have wide molecular weight distribution, makingthem less applicable to control morphology in the solid. Asynthetic procedure for the preparation of PPV reported byKretzschmann and Meier 2 is adopted in this research plan becausethe synthesized PPV shows low polydispersity index (PDI).RESEARCH METHODSThe research plan will be approached through organic synthesesfollowed by characterization of organic products in eachstep. The first step of the synthesis follows a Williamson ethersynthesis. The second step involves formylation of an aromaticcompound. The third step is a condensation reaction to form animine. The fourth step is a poly-condensation reaction where potassiumtert-butoxide is used. The fifth step is to regenerate thealdehyde through the hydrolysis of imine. The sixth step is thereduction of the aldehyde to a primary alcohol. The seventh stepcombines PPV, C60 and a polymerizable norbornene moiety toyield a norbornene-containing PPV-C60 dyads. The eighth stepfollows Williamson ether synthesis. A proposed synthetic schemeis shown in Figure 1.Figure 1. Proposed synthetic scheme for preparation of ROMP monomers.CMDITR Review of Undergraduate Research Vol. 2 No. 1 Summer 2005 17