HIGH-RESOLUTION ION MOBILITY STUDIES OF SODIUM-CHLORIDE NANOCRYSTALS

High-resolution ion mobility measurements have been used to examine th e geometries of (NaCl)(n)Cl- clusters with up to 49 NaCl units. Steps in the relative inverse mobilities as a function of the number of NaCl units are due to completion of the 4 x 3 x 3, 4 x 4 x 3, 4 x 4 x 4, a nd 5 x 4 x 4 cuboids. For clusters with more than 30 NaCl units severa l families of isomers, with different cuboid or incomplete cuboid geom etries, have been resolved at room temperature. The resolved isomers a re assigned to specific geometries by comparing the measured mobilitie s to mobilities calculated for geometries optimized using an ionic pot ential.