Effect of cytosine–Ag⁺–cytosine base pairing on the redox potential of the Ag⁺/Ag couple and the chemical reduction of Ag⁺ to Ag by tetrathiafulvalene

Abstract

[Ag(cytidine)2]+ formation can be utilized for controlling the redox potential of the Ag+/Ag couple.

Chemical reduction of Ag+ to Ag employing organic electron donors: evaluation of the effect of Ag+-mediated cytosine–cytosine base pairing on the aggregation of Ag nanoparticles

“…38,39 The UV–Vis spectroscopic analysis of the redox reaction between [Ag(cytidine) 2 ] + and TTF has been previously performed to evaluate the effect of C–Ag + –C base pairing on the chemical reduction of Ag + to Ag in DMSO. 28…”

“…Therefore, TDAE could effectively reduce the [Ag(cytidine) 2 ] + in DMSO even though C–Ag + –C base pairing makes it more difficult to reduce captured Ag + ions. 28 In the case of NTA experiments utilising TTF, the total concentration of the AgNP solution dramatically decreased. These results are consistent with the previous observation that cytidine inhibits the reduction of Ag + to Ag by TTF due to the formation of [Ag(cytidine) 2 ] + in DMSO.…”

“…Significant efforts have been devoted to the characterisation of cytidine/Ag + systems, including cytidine-related compounds such as 1-methylcytosine and 1-hexylcytosine. 19–27 Very recently, we utilised the [Ag(cytidine) 2 ] + complex as an isolated cytosine–Ag + –cytosine (C–Ag + –C) base pair to reveal that C–Ag + –C base pairing complicates the reduction of captured Ag + and lowers the half-wave potentials ( E 1/2 ) of the Ag + /Ag couple 28 (Fig. 1).…”

“…Further, we also reported the order of the E 1/2 values ( vs. Fc + /Fc) in dimethyl sulfoxide (DMSO) of the nucleoside/Ag + systems (cytidine/Ag + < guanosine/Ag + < adenosine/Ag + < thymidine/Ag + ). 28 Based on the formation of the [Ag(cytidine) 2 ] + complex in DMSO, a novel strategy for reducing Ag + could be developed. Such a strategy is possible because DMSO is an aprotic solvent that can dissolve Ag + as well as powerful reducing agents, including organic electron donors 29,30 such as tetrakis(dimethylamino)ethylene (TDAE) and tetrathiafulvalene (TTF) (Fig.…”

“…The well-characterised cytidine/Ag + system in DMSO 28,31 facilitates the evaluation of the effect of C–Ag + –C base pairing on the degree of AgNP aggregation in solution. Such experimental evaluation benefits the synthesis of AgNPs since the colloidal stability and function of NPs are influenced by the selected capping ligands.…”