Electrochemical functionalization

Recently, the electrochemical functionalization of organic halides using sacrificial anodes has been remarkably developed [18]. The general mechanism can be schematically shown for the generation of a divalent cation as shown in Scheme 3.9. 

For further details the reader is referred to the excellent paper by Chaussard et al. [149] Use of sacrificial anodes in electrochemical functionalization of organic halides and the paper by Silvestri et al. [178] Use of sacrificial anodes in synthetic electrochemistry. Processes involving carbon dioxide . 

Scheme 3 Classification of electrochemical functional group interconversions (FGI s).

Electrochemical functions H, Na, K, Cl, Mg, Ca, HPO Free Ions Osmotic regulation transmission of chemical signals energy production Including light harvesting... 

Ion exchange or ion transfer membranes have two important types of function in practical operating electric membrane systems an electrochemical function, and a structural function. 

In 2002, Burghard and coworkers described an elegant method for the electrochemical modification of individual SWCNTs [177]. To address electrically individual SWCNTs and small bundles, the purified tubes were deposited on surface-modified Si/Si02 substrates and subsequently contacted with electrodes, shaped by electron-beam lithography. The electrochemical functionalization was carried out in a miniaturized electrochemical cell. The electrochemical reduction was achieved by reduction of 4-N02C6H4N2+BF4 in DMF with NBu4+BF4 as the electrolyte (Scheme 1.27a), anodic oxidation was accomplished with aromatic amines in dry ethanol with LiC104 as the electrolyte salt (Scheme 1.27b) [177]. 

Electrochemical functionalization - reductive coupling of diazonium salts The electrochemical functionalization of SWCNTs, deposited on an Si/Si02 substrate, with 4-nitrophenyl groups succeeded by the reduction of 4-nitrobenzene-diazonium salt in a mini-electrochemical cell with platinum counter and (pseu-do-)reference electrodes. A probe needle was used to make contact with one of the Au-Pd bonding pads on the substrate and allowed the application of an electric potential to the electrode (-1.3 V vs. Pt for >30 s) and to any SWCNTs underneath the electrode [177b]. 

It is difficult to give a general formula covering all electrochemical functional group conversions, but these examples should be suf-... 

Reedy CJ, Elvekrog MM, Gibney BR (2007) Development of a heme protein structure-electrochemical function database. Nucleic Acids Res 36 D307-13... 

Related photochemistry has also been examined with other functional groups such as phthalimides, which also abstract nearby hydrogens with the photoexcited carbonyl group. - Furthermore, since the hydrogen abstraction is performed by the half-vacant nonbonding orbital of a photoexcited ketone carbonyl, related chemistry is observed if the electron is removed electrochemically, not just photoexcited into a Tr -orbital. Electrochemical functionalization of nearby carbons has been reported in which, after hydrogen atom abstraction by an oxidized ketone, the resulting radical is electrochemically oxidized further to the carbon cation, which reacts with solvent (Scheme 7). ... 

Desulfurization of thiophenes 88MI17 89CRV459 90MI13. Electrochemical functionalization of halothiophenes 90S369. Electrophilic substitution of thiophenes 86HC(44,2)1. 

Electrochemical functional-group interconversions can be classified into four groups [Eq. 

Zhang YJ, Li JH, Niu L et al (2005) Electrochemical functionalization of single-walled carbon nanotubes in large quantities at a room-temperature ionic liquid supported three-dimensional network electrode. Langmuir 21 4797-4800... 

Wei D, Kvamstrom C, Lindfors T et al (2007) Electrochemical functionalization of single walled carbon nanotubes with polyanUine in ionic liquids. Electrochem Commun 9 206-210... 

Guo, K. T., Schamweber, D., Schwenzer, B., Ziemer, G., Wendel, H. P. (2007). The effect of electrochemical functionalization of Ti-alloy surfaces by aptamer-based capture molecules on cell adhesion. Biomaterials 28, 468-474. 

In the CP/CNT composite field, special attention has been given to the functionalization of the side wall of SWNTs with CPs having repeating units such as thiophene rings [112]. An example is SWNTs electrochemically functionalized with PEDOT. For covalent functionalization, a significant change is observed in the structure of the G band, which... 

M. Baibarac, M. Lira Cantu, J. Oro Sole, N. Casan Pastor, and P. Gomez Romero, Electrochemically functionalized carbon nanotubes and their appUcation to rechargeable... 

Electrochemical functionalization of single-walled carbon nanotubes (SWNTs] with PANl has also been done in ionic liquids [197], SWNTs are covalently functionalized during the electropolymerization of aniline in ionic liquids. This methodology provides a novel way by which large amount of SWNTs (15 mg/ml] can be modified by aniline electro chemically. 

Zhang X, Tretjakov A, Hovestaedt M, Sun G, Syritski V, Rent J, Volkmer R, Hinrichs K, Rappich J (2012) Electrochemical functionalization of gold and silicon surfaces by maleimide-group towards biosensor for immunological application. Acta Biomater 9(2013) 5838-5844... 

Unger, E., Graham, A., Kreupl, F., Liebau, M., and Hoenlein, W., Electrochemical functionalization of multi-waUed carbon nanotubes for solvation and purification, Curr. Appl. Phys., 2 (2), 107-111, 2002. 

Direct electrochemical functionalization of C(sp )—H-bonds in arenes and hetarenes 13UK747. 

When the silver electrode covered by a cyt. c layer is transferred into 4-PySSPy solution, the SERRS signals of cyt. c disappear because cyt. c is completely displaced by 4-PySSPy. However, cyt. c is subsequently immobilized on top of the 4-PySSPy modified electrode and a rapid electrode reaction takes place at the formal potential of the native one. The adsorption of bis-(2-pyridyl) disulfide (2-PySSPy) and cyt. c is competitive. Bis-(2-pyridyl) disulfide coadsorbs with cyt. c on the silver electrode and the electrochemical function of this adsorbed layer is similar to that of the film formed by 4,4 -bipy coadsorbed with cyt. c. 

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