Motionally narrowed isotropic ' H NMR line shapes are observed for the adamantane-d16-thiourea inclusion compound, 1, at temperatures between 333 and 119 K. The zH NMR spin-lattice relaxation times indicate that reorientational motion of the guest is taking place on the picosecond time scale at 300 K. The zH NMR data suggest that there is only one solid phase for 1 over the temperature range studied and that the effective barrier to overall reorientation of the guest is small, 11.1 f 1.1 kJ mol-'. Isotropic *H NMR line shapes are also observed for the guest in the bicyclo[2.2.2]octane-dZ-thiourea inclusion compound, 2, between 333 and =183 K. At temperatures less than 183 K a small quadrupolar splitting develops in the *H NMR line shape, suggesting that a phase transition has taken place. Below 164 K a second splitting in the line shape is apparent, implying that there are at least two different guest sites. While the magnitude of the first observed quadrupolar splitting remains essentially independent of temperature, the second splitting increases as the temperature is decreased. The zH NMR spin-lattice relaxation times of the guest in 2 appear to be continuous over the complete temperature region investigated, 333-123 K. The correlation time for overall reorientations of bicyclo[2.2.2]octanc-dz in 2 is less than 3 X 10-9 s at temperatures above 123 K, and the E A for this motion is 9.4 f 0.9 kJ mol-'.

Ni particles were grown on Si(100) by MOCVD from Ni(η5-C5H4Me)2 in the presence of H2. There is an induction period which is a function of the precursor flux. The Ni particle size is a function of the deposition time and precursor flux. For example, with precursor held at 47 °C, the particle size increases from 140 nm (5 min) to 180 nm (10 min) to 260 nm (20 min) as the deposition time is increased. TiCl4 surface treatment (a) and gas-phase addition of H2O (b) were explored further to influence growth. Both methods increase the growth rate as measured by the Ni(111) XRD peak intensity. (a) The TiCl4 reacts with surface OH groups to form TiO2 islands which act as nucleation sites for Ni growth. A 5 min exposure to TiCl4 results in large (1 mm) amorphous and oriented crystalline TiO2 islands. The Ni crystals first saturate the TiO2 islands and then break off to form individual islands. (b) The gas-phase addition of H2O into the carrier gas stream results in initial formation of large particles which later break up into smaller particles. The size and number of particles are functions of the concentration of H2O in the gas phase.