Molybdenum bronze

These compounds form deeply coloured plate-like crystals with a metallic sheen, hence their name.

These compounds have been much studied since the 1980s due to their markedly anisotropic electrical properties, reflecting their layered structure.

They reported that electrolysis of molten Na2MoO4 and MoO3 gave indigo-blue needles with metallic sheen, which they analysed by weight as Na2Mo5O7.

This report also called attention to the marked anisotropic resistivity of the purple lithium bronze Li0.9Mo6O17 and its metal-to-insulator transition at about 24 K.[5] Hydrogen bronzes HxMoO3 were obtained in 1950 by Glemser and Lutz, by ambient-temperature reactions.

[6][Note 1] The hydrogen in these compounds can be replaced by alkali metals by treatment with solutions of the corresponding halides.