Condensed Vanadate-Phosphates

Glasses of sodium vanadate-phosphates with P/V ratios of 1∼200 were prepared from mixtures of sodium metaphosphate, vanadium (V) oxide and sodium carbonate. Crystals of sodium vanadate-phosphates with P/V ratios of 7, 10 and 50 were also prepared. During the preparation of the glasses and the crystals, a part of the vanadium(V) is reduced to vanadium(IV). The percentages of vanadium(IV) in relation to the total vanadium increase with an increasing P/V ratio. From the paper chromatographic analyses of the aqueous solutions of the glasses and the crystals, it may be presumed that the glasses are mainly composed of chain structures such as ……O–P–O–P–O–V–O–P–O–…… and that the crystals contain considerable amounts of a vanadate-phosphate ring as follows: (Remark: Graphics omitted.)