For highly reactive compounds that are very sensitive to protic impurities, it may be necessary to silanize the glassware prior to use. The surface of glass contains Si-OH bonds and the goal of silanization is to convert these into less reactive Si-O-Si bonds.
Step 1: The glassware is soaked for 15-30 minutes in a 5% solution of dichlorodimethylsilane (Me₂SiCl₂) in dry toluene. Chlorotrimethylsilane (Me₃SiCl) can also be used as a substitute.
Step 2: The glassware is rinsed with dry toluene followed by dry methanol.
Step 3: The glassware is allowed to dry in an oven (>100 °C overnight) prior to use.
The Schlenk Line Survival Guide 