Small heterocyclic cations that bind to DNA are interesting systems to study due to their structural diversity, pharmaceutical potential, and characteristic target recognition patterns. Clinically, such compounds offer an attractive therapeutic approach as inhibitors of protein-DNA interactions implicated in disease. Due to their typical intrinsic fluorescence, these compounds also have potential as convenient biotechnological probes for studying DNA. Finally, from a biophysics perspective, an intricate understanding of the factors driving DNA binding by these compounds can extend our understanding of DNA targeting more broadly. In this thesis, the electrostatics and hydration properties of DNA binding by eight of these heterocyclic cations in complex with various DNA sequences are investigated.