The interactions of prototypical silane coupling agents with a clean and hydroxyl-predosed TiO2(110) single-crystal surface have been studied using surface spectroscopic techniques. The adsorption and reactions of vinyltriethoxysilane (VTES), diethyldiethoxysilane (DEDS), and (aminopropyl)triethoxysilane (APS) were studied by means of temperature programmed desorption (TPD) and X-ray photoelectron spectroscopy (XPS). Even in the absence of surface water or hydroxyls, VTES dissociates rapidly to form Si(OEt)(CH=CH2)(s) and two OEt(s) where Et=C2H5 and "s" refers to surface species. The DEDS similarly dissociates to produce a mixture of SiEt(2,s), EtOSiEt(2,s), and one to two OEt(s). Both of these silicon moieties are bound to the surface via Si-O-Ti bonds. Any EtO- ligands, whether bound to Ti cations or to the adsorbed silanes, decompose at similar to 650 K via beta-hydride elimination to create ethylene gas and a surface-bound hydrogen. (OHs). This hydrogen further reacts with a second EtO- ligand to produce ethanol gas. Above 700 K, the ethyl ligands left on the adsorbed silane produced from DEDS decompose via beta-hydride elimination to give ethylene gas. Similarly, the CH2=CH- ligands left on the adsorbed silane produced from VTES also decomposes through beta-hydride elimination into acetylene gas and surface hydrogen, but they hydrogenate to give ethylene much more rapidly. When hydroxyls are predosed on the surface, they react with any Ti4+-bound EtO- ligands formed in the initial decomposition of VTES and DEDS to produce ethanol gas at similar to 350 K. Thus, the main function of the hydroxyls is to clear Ti4+ sites of ethoxy groups, not to act as sites for the initial attachment of the silane to the surface. Neither TPD nor XPS data indicated that APS dissociated to a measurable extent on the TiO2(110) surface.