After one hour, 0.6 mL of the diluted sample was then transferred to a 5 mm NMR tube equipped with an air-tight Teflon™ valve and analyzed by H NMR spectroscopy at 500 MHz on a Bruker Avance 500 instrument, using a 30° pulsewidth and 5 sec relaxation delay averaging 64 transients. The spectra were integrated before and after baseline subtraction of the broad MAO resonance as described in the literature20 , 50 to determine total Al, Me3Al and [Me2Al(THF)2] + content.