Synthesis of tris(3-pyridyl)aluminate ligand and its unexpected stability against hydrolysis: revealing cooperativity effects in heterobimetallic pyridyl aluminates

We report the elusive metallic anion [EtAl(3-py)(3)](-) (3-py = 3-pyridyl) (1), the first member of the anionic tris(3-pyridyl) family. Unexpectedly, the lithium complex 1Li shows substantial protic stability against water and alcohols, unlike related tris(2-pyridyl)aluminate analogues. This stability appears to be related to the inability of the [EtAl(3-py)(3)](-) anion to chelate Li+, which precludes a decomposition pathway involving Li/Al cooperativity.

Automated summary

The study presents a rare metallic anion [EtAl(3-py)(3)](-) with high protic stability against water and alcohols, unlike related compounds, due to its inability to chelate Li+ and prevent a decomposition pathway involving Li/Al cooperativity.