The adsorption and reactivity of acrylic acid on clean and preoxidized Ni(111) have been examined under ultrahigh vacuum (UHV) conditions using reflection absorption infrared spectroscopy (RAIRS). On clean Ni(111), acrylic acid molecules that adsorb as dimers at 140 K subsequently decompose between 240 and 310 K into surface-bound acrylate species and eta(1)(O)-acrylic acid monomers attached to the surface through the lone pair electrons of the carbonyl O atom. On Ni(111)-p(2 x 2)-O, facile deprotonation of acrylic acid occurs at 240 K to yield upright symmetrically bound acrylate species. Increasing the coverage results in tilting of the acrylate species as a consequence of steric hindrance and repulsive dipolar interactions. An alternative synthetic route to stable surface-bound acrylate monolayers has also been achieved through O-induced nucleophilic substitution of acryloyl chloride on Ni(111)-p(2 x 2)-O.