Suzuki Coupling: Aqueous and Anhydrous Synthesis of Ferrocene-Capped Thiophene Bill Mitchell

Polythiophene Introduction Polythiophene –p-type semiconducting organic polymer –Tuneable electronic properties

Introduction Applications –Photovoltaics (solar cells) Cheaper Higher voltage Activated by visible light Tuning will improve efficiency –Transistors, light emitting diodes Cheaper More efficient Smaller

Introduction Problem –No cyclic voltammetry Polymerization Ferrocene –End-cap for thiophene –Electrochemically active Ferrocene

Introduction Short chain vs. long chain –Solubility –Yield –Accuracy n= 1, 2, 3 Short chain n= 3, 4 Long chain

Procedure 1: Aqueous 2,5-Diferrocenyl-Thiophene Suzuki Coupling –Aqueous Highly contaminated Low yield

Side Reaction

Anhydrous Coupling Organic soluble –Boronic ester –Less contamination –Higher yield 1-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-ferrocene

Procedure 2: 1-(4,4,5,5-Tetramethyl-1,3,2-Dioxabolan-2-yl)-Ferrocene (Boronic Ester)

Procedure 3: Anhydrous 2,5-Diferrocenyl- Thiophene In dioxane Reflux hr.

Results

Results: Aqueous 2,5-Diferrocenyl-Thiophene 1 H NMR spectrum 250 MHz

Conclusion Synthesize Ferrocene-Capped Thiophene –Aqueous method –Chromatography eluent less polar 50:50 hexane:dichloromethane 70:30 hexane:dichloromethane

Further Research Make Derivatives –Electron donating and withdrawing –Electrochemical characterization Variable temperature

Applications Photovoltaics Transistors

Suzuki Coupling: Aqueous and Anhydrous Synthesis of Ferrocene-Capped Thiophene Bill Mitchell

Chemical Shift