A new class of MRI (magnetic resonance imaging) contrast agents, named paraCEST (paramagnetic chemical exchange saturation transfer) MRI contrast agents, take advantage of the transfer of saturated magnetization to bulk water through exchangeable protons on the contrast agent. Because there is little known about how proton exchange directly relates to the efficacy of these paraCEST agents, it is the goal of this study to use substitutionally inert chromium(III)-based complexes to be able to interpret the mechanisms of exchange that can occur on paraCEST agents. By understanding the mechanisms of proton exchange that occur as a function of pH, it was shown in this study that the mechanism of exchange is dependent on the pH of the sample. Ammine ligands may only exchange through a base-catalyzed mechanism which occurs at a pH greater than 9 to increase the amount of proton exchange. At a pH range lower than 9, the observed relaxivity is possibly due to second-sphere and outer-sphere interactions. Water ligands require a more extensive interpretation as to the mechanism of exchange that occurs. At very low pH, an acid-catalyzed or interchange proton exchange mechanism are possible explanations that may explain a pH independent relaxivity trend. A water ligand at a pH from 2-3 may undergo a base-catalyzed proton exchange mechanism which will produce an increase in proton exchange. Amide ligands may undergo an acid-catalyzed proton exchange through an N-protonated mechanism, an interchange mechanism or no exchange which contributes to relaxivity through second-sphere and outer-sphere contributions, and a base-catalyzed mechanism at physiological pH that exchanges through an N-deprotonated mechanism for a bound amide or an O-deprotonated imidate intermediate for an unbound amide. The understanding of the mechanisms of exchange gives a preliminary insight to the parameter that influences both 1H relaxivity typically used for traditional T1/T2 complexes to be used as the basis to interpret how the mechanisms of exchange may modulate the CEST effect in experiments used to examine paraCEST contrast agents. It is the hope that the potential of this project may lead to the application of rationally designing an optimal paraCEST MRI contrast agent.