Adsorption-induced bending of a triatomic molecule: Near-edge x-ray absorption fine-structure spectroscopy investigation of N2O adsorbed on different Ni(111) surfaces

A monolayer of N2O/Ni(111), a submonolayer species, and a monolayer of N2O/Ni(111) + O p[2 x 2] were studied using near-edge x-ray absorption fine-structure spectroscopy. From the polarization dependence we derive bent N2O molecules for the monolayer species whereas the two other species remain linear upon adsorption. Using the X alpha-scattered-wave method the polarization dependence of the three pi* resonances was calculated explicitly for linear and bent N2O molecules. The calculations reproduced the experimental results quantitatively, yielding a bond angle of 165 degrees for the monolayer species.