A method and structure for sealing porous dielectrics using silane coupling reagents is herein described. A sealant chain (silane coupling reagent) is formed from at least silicon, carbon, oxygen, and hydrogen and exposed to a porous dielectric material, wherein the sealant chain reacts with a second chain, that has at least oxygen and is present in the porous dielectric defining the pores, to form a continuous layer over the surface of the porous dielectric.