We determined the desorption energies of O2 molecules from AunO2- (n = 2, 4, 6, 8, 10, 12, and 14) by gas phase thermal desorption spectrometry. Cluster anions, AunO2-, prepared in the gas phase were heated inside a temperature-controlled copper tube. Formation of Aun- from the desorption of O2 was observed as a function of temperature. Temperature dependence of the intensities of AunO2- and Aun- was analyzed using the Arrhenius equation, estimating the desorption energy of O2 from AunO2-. Considering the geometrical structure of AunO2-, the desorption energy must be the same as or slightly higher than the binding energy of O2 to Aun-, because the desorption of O2 proceeds by a simple bond cleavage of Aun--O2, without significant rearrangement of atoms in the cluster. The collision-induced dissociation experiments show that the desorption energy was nearly equal to or slightly lower than the threshold energy for n = 2, 4, and 6.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films