Ligand design is one of the most critical aspects of creating homogeneous organometallic systems capable of activating small molecules. By carefully tuning the structure and electronic properties of these compounds both the stability and reactivity of transition metal complexes can be customized to fulfill a variety of different purposes. Pincer ligands, which are tridentate frameworks coordinated to a metal centre in a meridional fashion, have become synonymous with facile ligand design. Their particular structure not only imparts increased stability but also allows for easy modification. Furthermore, metal complexes supported by these frameworks have been shown to have remarkable reactivity towards highly stable small molecules that are environmentally harmful, necessary for producing alternative fuel sources, such as ammonia or hydrogen gas, and are important to maintaining a sustainable future. This thesis describes the evolutionary design, syntheses and reactivity of a series of electron-rich amino functionalized iridium PCcarbeneP pincer chloride complexes containing the ortho-phenylene motif of its parent system. It highlights the decomposition of an early developed system via unwanted, irreversible C-C bond cleavage and details the subsequent syntheses of more rigid complexes bearing aryl-aryl linkages to prevent this issue. Ligand donor strengths of these complexes, which were evaluated by comparing carbonyl stretching frequencies of synthesized mono and dicarbonyl cations, were determined to be greater than the non-aminated systems and divergent reactivity between rhodium and iridium PCcarbeneP cations with CO was found. Furthermore, the new PCcarbeneP complexes showed an increased propensity to form “iridaepoxides” in the presence of N2O, with a direct positive correlation between ligand donicity and iridaepoxide formation rate being observed. One of the rigid PCP frameworks, comprised of a dihydroanthracene moiety, was also found to form an unprecedentedly stable polyhydride complex. This polyhydride readily formed tri- and monohydride species that facilitated either moderately selective or exhaustive hydrogen/deuterium exchange in the presence of a deuterium source. Moreover, the polyhydride was better suited for N2O reduction as the iridium PCcarbeneP chloride complex decomposed with exposure to H2. Using the dihydroanthracene-based polyhydride, catalytic reduction of N2O was attempted with H2 and minor catalytic conversion into N2 and H2O was observed.