Ion chromatography studies

In the experiments discussed in earlier sections, the separation of the metal carbide cluster ions produced either directly in the source or in the carrier gas was exclusively performed on a mass criterion. Ion chromatography experiments performed by Bowers and co-workers introduce another selection criterion by allowing a mass-selected ion cloud to undergo collisions with a He buffer gas in a drift cell [28,68] given species will depend on its collision cross section 

For Ti8Ci2, three structural isomers proposed as a result of theoretical investigations were compared with the structure of the pentagonal dodecahedron proposed by Castleman s group. The values of K obtained from Monte-Carlo simulation were then compared with the experimental mobility of 5.71 + 0.05 cm s (Fig. 

Although the pentagonal dodecahedron structure gives the best fit with experiment (-1-1.2%), the tetracapped tetrahedron structure proposed in independent work by Dance, Lin and Halfi and Rohmer et is also in reasonable agree- 

A similar study performed on TisCi3+ yielded excellent agreement between the experimental K value of 5.49 cm V s and a computed value based upon a pentagonal dodecahedron structure with an exohedral extra carbon. The value of K associated with an endohedral structure deviates from experiment by as much 

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