Metal ions play crucial roles in diverse areas such as medicine, nanotechnology, catalysis, environmental sciences, and geochemistry. For example, the chemistry of metal ions with biomolecules and organic compounds is extremely important for a wide range of medicinal and environmental processes that depend on metal ions as active participants [1-3]. Organic complexes that coordinate to metal ions are becoming increasingly prevalent as therapeutic agents for treating a wide variety of metabolic disorders and diseases. For instance, cisplatin has been shown to be toxic to cancer cells (see Chapter 1 for a more detailed discussion of cisplatin) and the platinum-based compound known as “trans,trans,trans-Pt(N3)2(OH)2(NH3)(py)” has been shown to be highly toxic and less stable than cisplatin. It is between 13 and 80 times more toxic to cancer cells than cisplatin and kills cancer cells via a different mechanism so it can also kill cisplatin-resistant cancer cells. When we consider that most biological processes occur in solution and that the human body consists of ∼60% water, the role of the aqueous solution environment on the structure-function relationships of metal ion-based organometallic drugs cannot be ignored.