A linear CH+–NO3− base pair motif promoted by AgNO3 mediated proton transfer between guanosine and cytidine

Metallo-base pairs are of immense interest. However, uncertainties remain regarding Ag+–nucleic acid component interactions. Instead of a coordinated polymer [C–Ag][NO3] (1) embedded with Ag+ nanowires in an aqueous C/AgNO3 system, a novel base paired ionic crystal CH+–NO3− (2) was formed in a complex hydrogel system comprising guanosine (G), cytidine (C) and AgNO3. The static structural characteristics and underlying coupled reaction mechanisms driving the proton transfer between the G and C in this multi-component system were characterized. This information will be valuable in the context of bio-inorganic chemistry involving G- and C-rich genomic sequences.