The Development of tunable metalation resistant pincer ligands for supporting f-elements

xxvi, 171 leaves : ill. (some col.) ; 29 cmThe synthesis and characterization of a carbazole-based family of NNN tridentate pincer ligands and their respective organolanthanide chemistry was explored using both traditional synthetic and computational methodologies. The two modular ancillaries, a bis(phosphinimine)carbazole and a bis(pyrazolyl)carbazole ligand, were systematically developed with the intent of mitigating intramolecular cyclometalative reactivity that had been observed in previous ligand systems. The bis(phosphinimine)carbazole ligand was designed with geometrically constrained phospholane rings, which were incorporated into the ligand in a bid to reduce the propensity of cyclometalation at the PR2 site. The bis(pyrazolyl)carbazole ancillary explored the incorporation of strongly electron donating pyrazolyl rings into the ligand scaffold, as an alternative donor moiety to phosphinimines. Between the two scaffolds, distinguishable reactivity and stability was apparent upon formation of dialkyl lanthanide complexes. These differences were directly correlated to the unique steric and electronic properties provided by each framework