Mechanical processing of polycrystalline LiAlH in the presence of titanium-and iron-based catalysts induces the transformation of 4 LiAlH into Li AlH , Al and H at room temperature. Several catalysts were tested and it was established that their activity gradually 4 3 6 2 decreases from TiCl to Fe in the series TiCl .Al Ti4Al Fe Ti .Al Fe.Fe. The high catalytic activity of TiCl has been attributed 4 4 3 2 2 3 8 3 4 to microcrystalline intermetallic Al Ti, which rapidly forms in situ from TiCl and LiAlH during mechanical processing and then acts as 3 4 4 a heterogeneous dehydrogenation catalyst.

Self-assembled monolayer (SAM) structures and properties are dominated by two interactions: those between the substrate and adsorbate and those between the adsorbates themselves. We have fabricated self-assembled monolayers of m-1-carboranethiol (M1) and m-9-carboranethiol (M9) on Au[111]. The two isomers are nearly identical geometrically, but calculated molecular dipole moments show a sizable difference at 1.06 and 4.08 D for M1 and M9 in the gas phase, respectively. These molecules provide an opportunity to investigate the effect of different dipole moments within SAMs without altering the geometry of the assembly. Pure and co-deposited SAMs of these molecules were studied by scanning tunneling microscopy (STM). The molecules are indistinguishable in STM images, and the hexagonally close-packed adlayer structures were found to have ((square root of 19) x (square root of 19))R23.4 degrees unit cells. Both SAMs display rotational domains without the protruding or depressed features in STM images associated with domain boundaries in other SAM systems. Differing orientations of molecular dipole moments influence SAM properties, including the stability of the SAM and the coverage of the carboranethiolate in competitive binding conditions. These properties were investigated by dynamic contact angle goniometry, Kelvin probe force microscopy, and grazing incidence Fourier transform infrared spectroscopy.

Mechanochemical processing of polycrystalline LiAlH revealed good stability of this complex aluminohydride during high-energy 4 ball-milling in a helium atmosphere for up to 35 h. The decomposition of lithium aluminohydride into Li AlH , Al and H is observed 3 6 2 during prolonged mechanochemical treatment for up to 110 h and is most likely associated with the catalytic effect of a vial material, iron, which is introduced into the hydride as a contaminant during mechanical treatment.