2-Iodoethanol adsorbs on Ag(1 1 1) to form 2-hydroxyethyl species which react at similar to 230 K to eliminate water and ethylene and to deposit species of stoichiometry C2H4O. At high coverages, this forms predominantly oxametallacyclic species which exhibit vibrational modes at 759, 972 and 1069 cm(-1). The oxametallacycle thermally decomposes forming acetaldehyde. The reflection-absorption infrared spectra of both ethylene and ethylene oxide adsorbed on oxygen-activated Ag(1 1 1) at 300 K under a pressure of 1 Torr show that they react to form both acetaldehyde and ethylene oxide species. Ethylene oxide adsorbs at high pressures via the oxygen atom with the molecular plane tilted with respect to the (1 1 1) surface. All of the adsorbed ethylene oxide and the majority of the acetaldehyde desorb on heating to 390 K, with the remainder of the acetaldehyde being removed by heating to 450 K. These results are in accord with previous temperature-programmed desorption data which showed the formation of acetaldehyde, ethylene oxide and CO2 in this temperature range.