Surface immobilized azomethine for multiple component exchange

Abstract

Diazonium chemistry concomitant with in situ electrochemical reduction was used to graft an aryl aldehyde to indium-tin oxide (ITO) coated glass substrates. This served as an anchor for preparing electroactive azomethines that were covalently bonded to the transparent electrode. The immobilized azomethines could undergo multiple step-wise component exchanges with different arylamines. The write-erase-write sequences were electrochemically confirmed. The azomethines could also be reversibly hydrolyzed. This was exploited for multiple azomethine-hydrolysis cycles resulting in discrete electroactive immobilized azomethines. The erase-rewrite sequences were also electrochemically confirmed.

Building Tailored Interfaces through Covalent Coupling Reactions at Layers Grafted from Aryldiazonium Salts

“…Demonstrating this concept, Lerond et al grafted an anchor layer of −Ph−CHO groups to indium tin oxide (ITO), using a protected derivative. 82 Aryl amines were reacted with the layers giving azomethines, which could undergo multiple exchanges with other arylamines. Azomethines are electroactive, and hence the method gives surfaces with exchangeable tunable redox properties and, depending on the extent of conjugation of the arylamine, accompanying color changes.…”

“…The stability of bonding to the surface makes aryldiazonium grafting a good choice for the preparation of layers for repetitive, reversible chemical transformations. Demonstrating this concept, Lerond et al grafted an anchor layer of −Ph–CHO groups to indium tin oxide (ITO), using a protected derivative . Aryl amines were reacted with the layers giving azomethines, which could undergo multiple exchanges with other arylamines.…”

Effect of azomethine structural modification of electrochromic performance

“…Such conditions would otherwise hydrolyze the azomethine bond and should shift the oxidation potential to more positive potentials owing to a decrease in degree of conjugation. 23 The absence of electrochemical change under known hydrolysis conditions illustrates the robustness of the immobilized layer and its resistance to hydrolysis.…”

Engaging the Reversible Bonds of an Immobilized Styreno-Thiophene Film

“…It should therefore undergo both hydrolysis and dynamic component exchange, as per Figure . Both azomethine hydrolysis and its component exchange can readily be tracked by 1 H NMR with soluble azomethines. − However, solution-based characterization methods are not suitable for monitoring these processes of the insoluble poly-2A . Given that the intrinsic red color of the polymer film is from the conjugated framework, it is an ideal probe to monitor both the hydrolysis and component exchange reactions.…”