Structure of Amorphous MoS3

The amorphous compound MoS3 has been investigated by monochromatic X-ray photoemission ( X P S) and vibrational spectroscopy, as well as by chemical extrusion aimed at identifying structural units inside MoS3. XPS shows that all molybdenum in MoS3 occurs in the 4-t oxidation state, while sulfur is present in at least two states, including S2- and Sz2- ligands in different types of coordination. This composition corresponds to a formal charge state of MorV(S2-)&-). The emission infrared spectrum of MOS3 exhibits characteristic vibrations that are also encountered in the spectra of triangular MON3Sx cluster compounds. Three of such cluster compounds, i.e. (NH&[MotV3S~3]*H20, K s [ M o ~ S ~ ( C N) ~ ~. ~ H ~ O, and (NEt&[MotV3S7C16] can be extruded from MoS3 by reactions that are essentially destructive. On the basis of these results it is proposed that MoS3 is essentially an aggregation of M~(IV)~-sulfur cluster types.