Crystallographic and Computational Study on Cationic Triply Hydrogen-Bonded Nucleobases without Direct Anionic Stabilization

[(1MeCH)­(1MeC)]­(I3)­·2H2O (1MeC = 1-methylcytosine) (1) displays a single hemicytosinium i-motif, which is surrounded by four water molecules and interestingly does not exhibit direct interactions with anions. Quantum chemical calculations in water (SMD solvent model) reproduce accurately the geometry of the “water-submerged” cation 1. Furthermore, we performed stabilization and proton transfer studies, as well as an evaluation and rationalization of the influence of surrounding molecules enclosing lone electron pairs on triply hydrogen-bond connected nucleobases.