And the last of our "click" silanes. The two methyl groups "protect" the Si-O bond formed with substrate's hydroxyls, thus making it more stable towards hydrolysis than in the case of corresponding trichlorosilanes. The presence of only one chlorine atom (i) eliminates the possibility of condensation (cf. "Silanes tutorial" section on page 37 of ProChimia Catalog file) prior to surface binding and (ii) minimizes formation of multilayers. Since chlorosilanes hydrolize readily with liberation of HCl, they should be stored under inert atmosphere and should not be exposed to ambient moisture.