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Restacked single-layer MoS2 films have been studied by polarized X-ray absorption spectroscopy at the S K and Mo Lm edges. These restacked single-layer MoS2 films were obtained by exfoliation of MoS2 powder and subsequent collection of the single molecular layer of MoS2 onto a glass substrate. Films with and without tetrachloroethylene (TCE) included between the layers were obtained. The interlayer spacing of the film without tetrachloroethylene is 6.2 Á, and there is a 4.0-Á interlayer expansion on introducing TCE molecules between layers of MoS¡¡. The S K-edge X-ray absorption spectra of restacked single-layer MoS2 films with and without TCE included between the layers have been compared with that of MoS2 powder. A few percent of sulfate anion was found in the restacked single-layer MoS2 films; it may originate from the partial decomposition of the molybdenum disulfide. Apart from that, the S K-edge absorption spectra of restacked single-layer MoS2 films with and without TCE are similar to that of MoS2 powder. This suggests that the chemical bonding of the S atom in the restacked MoS2 films is identical with that found in crystalline MoS2. In particular, we found no evidence for the presence of a new axial ligand on the S atom that should have manifest itself by introducing a new absorption band below the ionization threshold. Also, no difference was observed at the Mo Lm edge between the restacked single-layer MoS2 films and the MoS2 powder. Recently, novel materials have been obtained by restacking single-layer molybdenum disulfide with organic molecules included between the layers.3-4 Molybdenum disulfide is a compound semiconductor, consisting of * To whom correspondence should be addressed.

Reactions involving methyl b-cellobioside and several oxygen species were used to investigate cleavage of glycosidic linkages in cellulose by reaction with photochemical hydroxyl radicals. The intent is not to reproduce delignification conditions, but rather to study the specific behavior of carbohydrate models toward hydroxyl radical. Experiments show that hydroxyl radicals are responsible for the degradation of glycosidic linkages in methyl b-cellobioside by substitution reactions displacing cellobiose, D-glucose, methyl b-D-glucoside, and methanol. Once the glycosidic linkages are broken, the reducing carbohydrates undergo a series of reactions forming 67

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