TY - GEN
T1 - Electrochemical reduction of AQ27DS in aqueous solution
AU - Sequeira, César A. C.
AU - Lobo, R. F.
AU - Anastassakis, G.
PY - 2006/12/1
Y1 - 2006/12/1
N2 - It is known that anthraquinone derivatives act as aqueous sulphide oxidation catalysts, so the redox chemistry of the compound anthraquinone 2,7-disulphonate (AQ27DS) stimulated our interest, as reported here. AQ27DS was reduced in aqueous solution at pH 9.0 to give a deep red coloured air-sensitive solution. Cyclic voltammetry and exhaustive electrolysis indicated that the anthraquinone was reversibly reduced in a two electron, one proton process at a variety of electrode surfaces. From limiting current results at a rotating disc electrode, the diffusion coefficient of AQ27DS was calculated to be 3.37 × 10-10 m2 5-1. Spectroscopic results confirmed that AQ27DSH- was the major reduced species, but also indicated that the di-anion (AQ27DS2-) and radical species AQ27DS were also present. ESR spectroscopy showed that the radical was formed via a comproportionation reaction between the di-anion and the AQ27DS starting material. The peak separation from voltammetry enabled the comproportionation constant (K c) to be estimated, and it was found to be in the range of 0.4 to 4.
AB - It is known that anthraquinone derivatives act as aqueous sulphide oxidation catalysts, so the redox chemistry of the compound anthraquinone 2,7-disulphonate (AQ27DS) stimulated our interest, as reported here. AQ27DS was reduced in aqueous solution at pH 9.0 to give a deep red coloured air-sensitive solution. Cyclic voltammetry and exhaustive electrolysis indicated that the anthraquinone was reversibly reduced in a two electron, one proton process at a variety of electrode surfaces. From limiting current results at a rotating disc electrode, the diffusion coefficient of AQ27DS was calculated to be 3.37 × 10-10 m2 5-1. Spectroscopic results confirmed that AQ27DSH- was the major reduced species, but also indicated that the di-anion (AQ27DS2-) and radical species AQ27DS were also present. ESR spectroscopy showed that the radical was formed via a comproportionation reaction between the di-anion and the AQ27DS starting material. The peak separation from voltammetry enabled the comproportionation constant (K c) to be estimated, and it was found to be in the range of 0.4 to 4.
KW - Anthraquinone-disulphonate
KW - Cyclic voltammetry
KW - Electrochemical reduction
KW - Exhaustive electrolysis
KW - Rotating disc electrode
KW - Spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=38049078854&partnerID=8YFLogxK
U2 - 10.4028/www.scientific.net/MSF.514-516.1338
DO - 10.4028/www.scientific.net/MSF.514-516.1338
M3 - Conference contribution
AN - SCOPUS:38049078854
SN - 9780878494026
VL - PART 2
T3 - Materials Science Forum
SP - 1338
EP - 1342
BT - Fast Software Encryption - 14th International Workshop, FSE 2007, Revised Selected Papers
A2 - Vilarinho, P. M.
PB - Trans Tech Publications Ltd
T2 - 3rd International Materials Symposium and 12th Portuguese Materials Society Meeting 2005
Y2 - 20 March 2005 through 23 March 2005
ER -