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

The redox properties of metallo-base pairs remain to be elucidated. Herein, we report the detailed H-1/C-13/Ag-109 NMR spectroscopic and cyclic voltammetric characterisation of the [Ag(cytidine)(2)](+) complex as isolated cytosine-Ag+-cytosine (C-Ag+-C) base pairs. We also performed comparative studies between cytidine/Ag+ and other nucleoside/Ag+ systems by using cyclic voltammetry measurements. In addition, to evaluate the effect of [Ag(cytidine)(2)](+) formation on the chemical reduction of Ag+ to Ag, we utilised the redox reaction between Ag+ and tetrathiafulvalene (TTF). We found that Ag+-mediated base pairing lowers the redox potential of the Ag+/Ag couple. In addition, C-Ag+-C base pairing makes it more difficult to reduce captured Ag+ ions than in other nucleoside/Ag+ systems. Remarkably, the cytidine/Ag+ system can be utilised to control the redox potential of the Ag+/Ag couple in DMSO. This feature of the cytidine/Ag+ system may be exploited for Ag nanoparticle synthesis by using the redox reaction between Ag+ and TTF.

Automated summary

The study revealed that Ag+-mediated base pairing lowers the redox potential of the Ag+/Ag couple, making it more difficult to reduce captured Ag+ ions. The cytidine/Ag+ system can be utilized to control the redox potential of the Ag+/Ag couple in DMSO, which may be exploited for Ag nanoparticle synthesis.