Electrically conducting oligo(pyrazoles)

Inventors

Martin, Brett D. • Trammell, Scott A. • Deschamps, Jeffrey R. • Naciri, Jawad • DePriest, Jeffrey

Assignees

US Department of Navy

Abstract

An electrically conducting organic oligomer comprising 3-amino-1H-pyrazole-4-carbonitrile, 3-amino-1H-pyrazole-4-carboxylic acid, 3-amino-4-nitro-1H-pyrazole, or 3-amino-1H-pyrazole-4-sulfonic acid. An electrically conducting organic oligomer comprising 4-nitro-1H-pyrazole-3-yl-amine, 4-trifluoromethyl-1H-pyrazol-3-yl-amine, 4-trichloromethyl-1H-pyrazol-3-yl-amine, 4-tribromomethyl-1H-pyrazol-3-yl-amine, 4-ammonium-1H-pyrazol-3-yl-amine, 4-trimethylammonium-1H-pyrazol-3-yl-amine, 4-triethylammonium-1H-pyrazol-3-yl-amine, or 4-tripropylammonium-1H-pyrazol-3-yl-amine, methods of making and products of the method thereof.

Core Innovation

This disclosure concerns two novel electrically conducting organic oligomers: oligo(3-amino-1H-pyrazole-4-carbonitrile) (oligo(AP-CN)) and oligo(4-nitro-1H-pyrazole-3-yl-amine) (oligo(AP-NO2)). These oligomers have highly variable redox states and good electron-transporting properties, making them potentially useful for applications such as polymer solar cells. The oligomers are synthesized easily, requiring only one step plus purification and use inexpensive starting materials.

The problem addressed is that most conducting polymers are p-dopable and act as carriers of positive charge, but stable n-dopable conducting polymers, which transport free electrons, are far less common. Existing materials for electron transporters like C60 fullerene are expensive, and synthesizing n-dopable polymers often requires many steps with complex ring-closing reactions. Thus, there is a need for electrically conducting organic oligomers that are stable in their n-doped state, easy to synthesize, cost-effective, and have enhanced electron transport properties to improve polymer photovoltaic efficiencies.

These new oligomers exhibit reversible n-dopability and potential p-dopability, high thermal stability with decomposition above 350° C., and generate photocurrents significantly higher than gold or fullerene-coated electrodes. Electrochemical impedance spectroscopy confirms their good electron conduction in reduced states. They are soluble in common polar solvents and have favorable structural and electrochemical properties, highlighting their suitability for practical incorporation into inexpensive, flexible polymer solar cells.

Claims Coverage

The patent contains one independent claim encompassing the core inventive features of the disclosed electrically conducting organic oligomers.

The claim covers oligomers composed of specific amino-substituted pyrazole derivatives, defining the chemical composition of the novel electrically conducting organic oligomers with variable redox and electron transporting properties.

Stated Advantages

Documented Applications