Procedure for preparing redox-active polymers on surfaces

Abstract

This invention provides novel methods for the formation of redox-active polymers attached to surfaces. In certain embodiments, the methods involve providing redox-active molecules bearing at least a first reactive site or group and a second reactive site or group; and contacting the surface with the redox-active molecules where the contacting is under conditions that result in attachment of said redox-active molecules to said surface via the first reactive site or group and attachment of redox-active molecules via the second reactive site or group, to the redox-active molecules attached to the surface thereby forming a polymer attached to said surface where the polymers comprise at least two of said redox-active molecules.

Description

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0001]This invention was made with Government support under Grant No: MDA972-01-C-072, awarded by the Army. The Government of the United States of America has certain rights in this invention.CROSS-REFERENCE TO RELATED APPLICATIONS[0002][Not Applicable]FIELD OF THE INVENTION[0003]This invention pertains to the field of molecular electronics. In particular, this invention pertains to improved methods to attach and polymerize redox-active molecules on surfaces.BACKGROUND OF THE INVENTION[0004]There has been considerable interest in the development of hybrid electronics devices and chips that utilize one or more organic molecules to store or manipulate information in discrete oxidation states of the molecule(s) (see, e.g., U.S. Pat. Nos. 6,208,553, 6,212,093, 6,272,038, 6,324,091, 6,381,169, and 6,451,942, and PCT Publication WO 01 / 03126, etc.).[0005]In certain embodiments, an electroactive (red...

AI Technical Summary

Benefits of technology

[0008]This invention pertains to the discovery that one solution to this problem of small feature size in molecular memory and related applications, is to stack information storage molecules (e.g. redox-active molecules) in the Z-dimension (the direction perpendicular to the substrate surface. We have found that porphyrinic macrocycles and other redox-active molecules can be made to polymerize under the conditions that we typically employ for forming monolayers on silicon, and other, surfaces. Moreover it was a surprising discovery that the redox-active polymers are electrochemically robust (capable of many read / write cycles) and exhibit charge-retention times that are comparable (or longer) than those of monolayers of the same molecules.

Problems solved by technology

General challenges in fabricating a hybrid chip containing molecular materials for information storage include, but are not limited to the efficient and effective attachment (electrical coupling) of the charge-storage molecule to an electroactive surface, controlling placement of the charge storage molecule(s) and / or associated electrolyte(s), and controlled deposition / location of counter electrodes.

Particularly pressing problems are that often the methods for attachment of molecules to surfaces often require very high concentrations, high temperature, and / or the use of reactive intermediates (see, e.g. Cleland et al.

Such conditions are readily applicable to small robust molecules but become less satisfactory and often fail altogether as the molecules become larger and / or more elaborate.

Another problem is associated with increased miniaturization of the electroactive memory elements.

Consequently, it becomes increasingly difficult to detect the stored charge.

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