Determination of intramolecular bond lengths of low-Zmolecules in the gas phase, condensed, and chemisorbed states using extended x-ray absorption fine structure

Extended x-ray absorption fine structure studies have been performed above the oxygen K edge for ${\mathrm{SO}}_2$ in the gas phase as well as condensed and chemisorbed on Cu(100) and for CO chemisorbed on the same surface. The analysis of the pronounced oscillations shows that intramolecular bond lengths of low-Z molecules can be directly determined with high accuracy. The extended x-ray absorption fine structure technique thus possesses the unique capability of measuring these bond lengths in gas phase, condensed, and chemisorbed molecules.