“…Scorpionate ligands, on the other hand, were first developed in the late 1960s by Trofimenko, and include species like tris(pyrazolyl)borate , and tris(pyrazolyl)methane (Figure ). The defining features of these ligands are a fac coordination geometry and the ability to interchange between tridentate and bidentate binding modes. , This hemilability can lead to higher reactivity levels over other tridentate ligands, such as pincer ligands, which tend to form very stable complexes. , Moreover, scorpionate ligands are extremely versatile in that their bonding strengths, electronic parameters, and steric encumbrance can be readily tuned. Since their development, complexes incorporating these types of ligands have been widely studied for medical purposes, catalysis, as well as other applications. ,, Surprisingly, despite their versatility, to the best of our knowledge, only a handful of scorpionate ligands have been explored on aluminum centers. − Martínez et al investigated a family of aluminum scorpionate complexes for the catalytic synthesis of cyclic carbonates from epoxides and carbon dioxide. ,− Additionally, aluminum scorpionate complexes have been utilized by the Otero group, and others, to affect the ROP of lactide and ε-CL. ,− By increasing the steric bulk of the tridentate ligands, more control over polymerization was seen and products with narrower PDIs were generated .…”