Films of both methoxy-terminated alkanethiols and a molecular wire candidate on Au {1 1 1 1} substrates were exposed to a variety of transition and alkali earth metals (Al, An, Ag, Ca, Cr, Fe, Cu, Mg, Ti). The results show that aggressively reacting metals, such as Ti, destroy the organic monolayer and metals of intermediate reactivity, e.g. Cu, react at the termini and also penetrate the monolayer and react with the substrate. The results of these investigations provide a basis by which future construction of molecular devices based on desired chemical reactivity may proceed. (C) 2002 Elsevier Science B.V. All rights reserved.