Carrier concentration dependent conduction in insulator-doped donor/acceptor chain compounds

Area of Science:

• Materials Science
• Solid-State Chemistry
• Supramolecular Chemistry

Background:

• Designing mixed valence systems is crucial for developing electronic conducting frameworks.
• Ionic donor/acceptor (D(+)A(-)) chains offer a platform for creating such systems.
• Controlling valency states is key to achieving desired electronic properties.

Purpose of the Study:

• To propose a rational strategy for creating mixed valency in ionic D(+)A(-) chains.
• To demonstrate the feasibility of doping these chains with redox-inert materials.
• To establish a method for achieving electron transport along the framework.

Main Methods:

• Synthesizing an ionic donor/acceptor chain using a redox-active [Ru2(II,II)] paddlewheel complex and a TCNQ derivative.
• Introducing a redox-inert [Rh2(II,II)] complex as a dopant into the D(+)A(-) chain.
• Characterizing the resulting material to confirm the creation of mixed valency and electron transport pathways.

Main Results:

• Successfully created mixed valency A(0)/A(-) domains within the doped ionic chain: P-(D(+)A(-))nA(0)-P.
• Demonstrated that the extent of mixed valency (n) is dependent on the dopant ratio.
• Confirmed electron transport along the framework, facilitated by charge transfer through the dopant units.

Conclusions:

• The doping of ionic D(+)A(-) chains with redox-inert dopants is a viable strategy for generating electronic conducting frameworks.
• This approach allows for rational control over mixed valency and electron transport properties.
• The experimental validation using [Ru2(II,II)] and [Rh2(II,II)] complexes opens new avenues for designing functional electronic materials.