PREPARATION AND CHARACTERIZATION OF A SODIUM INSERTION COMPOUND OF HYDROGEN MOLYBDENUM BRONZE, NA0.25(H2O)Y[H0.21MOO3]

A new red hydrogen-sodium co-insertion compound of molybdenum trioxide , Na0.25(H2O)y[H0.21MoO3], has been prepared which possesses sodium io ns in its interlayer space and protons in the intralayer positions. Tw o phases of this compound were observed depending on hydration water c ontent. According to XRD investigations, there was little difference i n crystal structure between this compound and hydrated sodium molybden um bronze. The Na-H co-insertion molybdenum bronze was characterized b y XRD, NMR and thermogravimetric and differential thermal analysis (TG -DTA) and showed an interesting structural transformation at ca. 550 K which was related to the change in interlayer spacing. It is suggeste d that the transformation results from structural defects generated by dehydration due to intralayer protons.