Preparation and electrochemical behaviour of hydrophobic vitamin B12 covalently immobilized onto platinum electrode

Abstract

Hydrophobic vitamin B(12) was covalently immobilized onto a platinum electrode surface, and the immobilized complex exhibits Co(ii)/Co(i) redox couple and in situ the Co(i) species reacts with phenethyl bromide to form styrene under irradiation with visible light with a turnover number of over 6000 for 1 h.

Quantifying the Electrocatalytic Turnover of Vitamin B12‐Mediated Dehalogenation on Single Soft Nanoparticles

“…Then, the catalytic efficiency of single soft nanoparticles k cat / K is estimated to be 7.8×10 3 m −1 s −1 , which is comparable to the value obtained from electrocatalytic reduction of ethylene dibromide in an emulsion system by Vitamin B 12 molecules . The maximum turn‐over number is found to be higher than the dehalogenation reported for Vitamin B 12 molecules covalently immobilized onto the electrode, where in the latter case a multi‐layer film was likely formed, while a complete electrolysis of Vitamin B 12 molecules encapsulated within single nanodroplets is thought to occur.…”

The Quest for Electrodes Coated with Vitamin B12 Derivatives

“…The use of electrodes with catalysts grafted to them make the isolation of products in semipreparative reactions highly efficient. Electrochemical studies of catalytic reactions using electrodes coated with B 12 derivatives have inter alia been reported by Rusling (11), Zagal (12) Hisaeda (13). Using derivatives of hexamethyl cobyrinic acid 2 we and Abrantes, have explored in joint ventures a variety of methods for grafting B 12 derivatives onto several electrochemical substrates and studied their catalytic activities (14).…”

Electrogenerated Fe(I) Porphyrins: Efficient Electrocatalysts for Reductive Dechlorination of DDT in N,N′‐Dimethylformamide

“…It has long been known that macrocycles containing transition-metal ions can be used as catalysts for the reductive dehalogenation of organohalides [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Among the many examined catalysts, are the macrocycles of vitamin B 12 [17], phthalocyanines [4,18] and porphyrins [1,19] with a cobalt central metal ion.…”