Transcript Conducting Polyrotaxane: - Massachusetts Institute of
Conducting Polyrotaxane: Synthesis and Potential Applications
CHE S RY
Phoebe Kwan Swager Group MIT Department of Chemistry
Electronic Polymers a Gain Medium
Non-Linearity Responses(Amplification) From Transport Properties O O H N RO RO R R S N N
Exponential Increases
N H N Conduction Band h
N N OR OR
Energy Migration
e E g N
% Doping McQuade, Pullen, Swager,
Chem. Rev.
100, 2537-2574
2000
,
Valence Band Initial Report: Ions:
Zhou, Swager
J. Am. Chem. Soc.
Kim, McQuade, McHugh, Swager,
1995
,
Angew. Chem. 117
, 12593
2000
, 39, 3868 Crawford, Goldfinger, Swager
J. Am. Chem. Soc.
TNT:
Yang, Swager
J. Am. Chem. Soc.
1998 1998
, 120, 5187 , 120, 5321
FRET:
Levitsky, Kim, Swager
J. Am. Chem. Soc.
McQuade, Hegedus, Swager,
J. Am. Chem Soc.
1999 2000
, 121, 1466 , 122, 12389
Recent Works by:
Heeger, Schanze, Whitten, McBranch, Bazan, Wasielewski, Kimura, Ajayaghosh, Sailor
Conducting Transition Metal Hybrid Polymers Why Use Transition Metal Hybrid Materials?
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Metals Bind to Anions, Lewis Bases, and Gases
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Electrocatalysis, Magnetism
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Fluxional Properties-Allosterism, Actuation More Conductive State: Isoenergetic Oxidation Potentials Less Conductive State: Carrier Blocked by a Potential Wall Analyte M M M M M M M M M M M M Analyte M M M M
Electron In
The Role of Metal Ions
M M Electron Out
Design Principle
Tetrahedral cavity allows binding of metal ion Highly conducting Conjugated backbone O O O O O 14Å N N M N N O O O S O O O S O n Bulky stopper prevents stacking (aggregation) of conducting wires
Synthesis 1
Synthesis 2
Synthesis 3
PM3 Geometry Optimization by Spartan
PM3 Geometry Optimization by Spartan
Molecular Modeling
Molecular Modeling
Future Directions
• Prepare robust polymer thin films for electrochemical studies.
• Investigate electrical, chemical and magnetic properties of various metallorotaxanes.
• Test polymers as sensory materials for a variety of analytes, such as nitric oxide and fluoride ions.
• Create configurable memory devices.