Studies of copper hydride. Part 1.—Synthesis and solid-state stability

Copper hydride, CuH, has been prepared by the reduction of aqueous copper sulfate using hypophosphorous acid. The polycrystalline red–brown hydride has been analysed using transmission electron microscopy, powder X-ray diffraction (PXRD) and differential scanning calorimetry, and consists of agglomerates of needle-like particles ca. 100 Å in size. It is unstable at room temperature and, in an inert atmosphere, decomposes, as shown by powder XRD, to copper metal and hydrogen. Activation energies of 2.0, 8.5 and 4.7 (±0.4) kcal mol–1 were obtained for the induction, acceleratory and decay stages of the isothermal decomposition process below 100 °C. Above this temperature the solid melts.