Siloxane-anchored, nitrate-bearing, monolayer films have been fabricated and have been used as the precursors for the photochemical creation of uniformly hydroxylated monolayer surfaces. The surface hydroxyl groups have been shown to be reactive toward phosphorylation and, more importantly, they can serve as the base layer for addition of a subsequent siloxane-anchored monolayer. This approach provides an important new tool for monolayer transformation and allows for photocontrol of organic multilayer construction.