Surface-Modified Carbon Felts:  Possible Supports for Combinatorial Chemistry

Abstract

It is possible to prepare carbon-based analogues of the Merrifield resin by electrochemical reduction of diazonium salts or oxidation of aryl acetates on high specific surface area carbon felts. These modified felts can undergo further reactions: nucleophilic substitution, Suzuki reaction, and finally reductive electrochemical cleavage, taking advantage of the conductivity of the carbon felt. This provides a simple example of the possible use of electrochemistry in combinatorial synthesis.

Covalent modification of graphitic carbon substrates by non-electrochemical methods

“…Graphitic carbons have many attractive characteristics, including ease-ofhandling, low-cost, high mechanical stability and good electrical conductivity. The material is readily available in a number of forms including high surface area felts and cloths suitable as supports for combinatorial chemistry [1,2], carbon powders useful for chromatography [3], glassy carbon (GC) [4], a convenient material for planar electrodes and very smooth films of pyrolysed photoresist [5] suitable for applications in molecular electronics [6,7,8]. Another advantage of graphitic carbon is that the surface can be easily modified by methods which give very stable molecular coatings, attached by strong C-C [9] or C-N covalent bonds.…”

Covalent Modification of Glassy Carbon Surfaces by Using Electrochemical and Solid‐Phase Synthetic Methodologies: Application to Bi‐ and Trifunctionalisation with Different Redox Centres

“…[27,[35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50] The main strategy consists of immobilising a 4-nitrophenyl group at the carbon surface by reducing the corresponding diazonium salt, reducing the nitro group to an amine group, then allowing subsequent chemical modifications. [27,35,36,41,43,48,50] Other examples include the immobilisation of a 4-carboxyphenyl group, [39,42,46,47] 4-(chloromethyl)phenyl group, [37,38] 4-(aminoethyl)phenyl group, [40] and more recently phenylmaleimide group, [44] phenylazide or phenylacetylene groups, [45] and boronic acid group, [49] followed by further chemical modification at the reactive groups for the preparation of single modified carbon A C H T U N G T R E N N U N G electrodes.…”

Covalent Tethering of Organic Functionality to the Surface of Glassy Carbon Electrodes by Using Electrochemical and Solid‐Phase Synthesis Methodologies

“…[1,2] These attachment methods show good reproducibility, and the covalently bonded organic layers produced by them were found to be stable for long-term storage and upon sonication in aggressive solvents. [8] Further chemical modification can be performed on the electrodes through specific substituents (e.g., ÀCOOH, [9] ÀSO 3 H, [9] ÀNMe 2 [9] or À CH 2 Cl [10,11] ) present on the aromatic ring and used to bond metal complexes, [9] enzymes, [12] or as potential supports for combinatorial chemistry. [10] Of particular relevance to our work described here, Pinson, SavØant et al attached both pnitrophenol and p-acetamidophenyl radicals onto a carbon surface using diazonium salts.…”

“…[8] Further chemical modification can be performed on the electrodes through specific substituents (e.g., ÀCOOH, [9] ÀSO 3 H, [9] ÀNMe 2 [9] or À CH 2 Cl [10,11] ) present on the aromatic ring and used to bond metal complexes, [9] enzymes, [12] or as potential supports for combinatorial chemistry. [10] Of particular relevance to our work described here, Pinson, SavØant et al attached both pnitrophenol and p-acetamidophenyl radicals onto a carbon surface using diazonium salts. Electrochemical reduction of Abstract: Organic linkers such as (NBoc-aminomethyl)phenyl (BocNH-A C H T U N G T R E N N U N G CH 2 C 6 H 4 ) and N-Boc-ethylenediamine (Boc-EDA) have been covalently tethered onto a glassy carbon surface by employing electrochemical reduction of BocNHCH 2 C 6 H 4 diazonium salt or oxidation of Boc-EDA.…”