Presentation on theme: "1 Insulated Polythiophene Self-Threaded Conjugated Polymer via Alkyl Chain Straps Ryan M HARRISON Mentor: Kazunori SUGIYASU, Ph.D P.I.: Masayuki TAKEUCHI,"— Presentation transcript:
1 Insulated Polythiophene Self-Threaded Conjugated Polymer via Alkyl Chain Straps Ryan M HARRISON Mentor: Kazunori SUGIYASU, Ph.D P.I.: Masayuki TAKEUCHI, Ph.D Macromolecules Group 4 August 2008
2 Road to NIMS Johns Hopkins University Computational Proteomics Macromolecules Group Organic Synthesis NNIN-NIMS
3 The Molecular Wire Paradox High density deposition High charge density and mobility Easy charge injection Low density deposition Limited crosstalk and interference Precise band gap control Other High Quantum yield and efficiency Device fabrication with affordable/existing methods (e.g. spin-coating) Polymer network alignment 1 cm 1 / 2,500,000 4 nm1 nm
4 Insulated Molecular Wires “Rotaxane” “Wrapping” “Synthetic” Binding constant dependent. Susceptible to defects. Polythiophene is not an ideal “axis”. K. Yoshida, T. Shimomura, K. Ito, R. Hayakawa, Langmuir 1999, 15, 910 – 913. O.K. Kim, L.S. Choi, Langmuir 1994, 10, 2842 – J. Stahl, et. al., Angew. Chem. 2002,114, 1951 – 1957 Hydrophobically driven interaction in water (limited specificity). Limited solvent flexibility. “Built-in” insulation. Covalently bound wrap or macrocycle.
5 “Synthetic” Approach Only 2 examples in the review Angew. Chem. Int. Ed., 2002 Not polymer… Angew. Chem. Int. Ed., 1996 Only one side is covered… Other examples Org. Biomol. Chem., 2004, 2, Not polymer…
6 How Can We Make Insulated Polythiophene? ? Intramolecular Rotaxane???
7 Project Plan (i) Design, organic synthesis and characterization of monomer (SciFinder, 1 H-NMR, MALDI-TOF-MASS, X-ray crystallography) (ii) Polymerization, purification and characterization (Lots of reaction conditions, GPC, UV-vis and fluorescence spectra, STM) (iii) Application of “insulated polythiophene” (Electroluminescence: ref. Nature Materials, 2002, 1, 160.) Perfectly insulated?
8 Selectivity versus formation Kinetics Selective? versus
9 Selectivity versus formation Kinetics Control selectivity via strap length… C4 C6 C5
10 Control Compound: Synthesis
11 Control Compound: Characterization (H-NMR) Pure sample…Proceed with basic optical characterization 4C
12 Control Compound: Characterization (UV-Vis) λ max =270 λ max =283λ max =365 λ max =433 4C has double the Stokes Shift of Bithiophene (163nm versus 82nm)
13 Intramolecular Rotaxane: Synthesis
14 Intramolecular Rotaxane: Characterization (H-NMR) 5R 6R True inspiration for changing a reaction scheme…
15 Intramolecular Rotaxane: Deuteration 5R D D
16 HBHB H A + H C 5C Before HBHB H A + H C 5C After Intramolecular Rotaxane: Deuteration HAHA HBHB HCHC Is direct Lithiation selective to H A ?
17 Thank You! Questions? 質疑応答
18 Can we make an aligned film?
19 Control Compound: Characterization (H-NMR) Relatively pure sample…Proceed with 4C reaction 3C