Francesco Zaccaria
Methylaluminoxane (MAO), the product of the controlled hydrolysis of trimethylaluminum, is a fascinating compound that has puzzled inorganic and organometallic chemists for decades. Even though it was introduced in the 1970s, reached industrial applications in the 1990s and is currently the most important commercial cocatalyst for olefin polymerization, its structure and properties remain surrounded by mystery. Recently, the interest in MAO has revamped, sparked by new findings enabled by advanced spectroscopic and computational techniques. This Perspective analyzes these developments and highlights the remaining challenges in elucidating and tuning the characteristics of this unique compound.