Fluxional behavior of Al(Et)(q′)2 (q′=2-methyl-8-quinolinolato) studied by temperature dependent 1H NMR spectroscopy

Two α-CH2 hydrogens of the Et group in Al(Et)(q′)2 (q′=2-methyl-8-quinolinolato) show two 1H NMR peaks at different positions with a separation of 0.19 ppm at 25 °C, due to the presence of a chiral center at Al. On raising the temperature, the two peaks collapsed, and coalesced above 100 °C. The 1H NMR fluxional behavior is accounted for by simultaneous rotation of the q′ ligands, and kinetic parameters of kJ mol−1, kJ mol−1, J K−1 mol−1 are evaluated.