Electrospray ionization mass spectrometry of solutions containing adenine [or various methylated derivatives] (M) and AgNO₃ yields polymeric [M_x + Ag_y − zH]^{(y − z)+} species. The stoichiometry, collision-induced dissociation fragmentation pathways, and ion–molecule reactions with H₂O, CH₃OH, CH₃CN, BuNH₂, and pyridine for the adenine– and 1-methyladenine–silver complexes are consistent with model polymeric structures that comprise of [M₂Ag₂] closed “dimers”. The [(adenine)₂Ag₂] subunits involve N(3) and N(9) complexation and are linked via a bridging silver ion at the N(7) position. In contrast, the results from the 6-N,N-dimethyladenine–silver complexes are more consistent with a “linear model” polymeric structure. Other methylated adenine systems give different types of mass spectra, depending on the site of methylation. Maps in which the types of [M_x + Ag_y − zH]^{(y − z)+} polymer ions observed are generated as a function of M (where M_x = number of adenine or methyladenine units) versus the number of silver ions highlight those systems which follow the “linear model” for polymeric ions and those which do not.