Self-assembled monolayers (SAMs) of alkyl phosphonic acids were assembled on single crystalline rutile TiO2 (110) (1x1). The substrates of TiO2 were carefully prepared through annealing and argon sputtering in ultra-high vacuum to yield a “nearly-perfect” surface. The surface state before synthesis was examined using x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and atomic force microscopy (AFM). The substrates were handled in an inert atmosphere until synthesis was complete to ensure that the SAMs were synthesized on a well-defined substrate. Infrared spectroscopy was used to determine the order of the SAMs. A grafting density for the SAMs was determined by thermogravimetric (TGA) analysis. We will report first results on the electronic and molecular structure of the SAM / TiO2 system.