Molecular motions in solid isotopic silanes
Abstract
This paper reports the results of measurements of some thermodynamic properties (heat capacities, vapour pressures, density, heats of fusion) of two silanes, SiH4 and SiHD3, over a wide temperature range above T= 2.8 K. Residual entropies (neglecting nuclear spins) have been computed to be –0.3 ± 0.3 cal mol–1 deg.–1 for SiH4 and 2.5 ± 0.3 cal mol–1 deg.–1 for SiHD3. These results together with published ones from other kinds of experiments are compared with the more extensive data that are available for the solid isotopic methanes. The similarities and differences are used for making deductions about molecular motions in the solid silanes.