Procedure 2 Sodium Intercalate of Tantalum Disulfide

Omloo and Jellinek have described the synthesis and characterization of intercalation compounds of alkali metals with the group V layered transition-metal dichalcogenides. Typically, these types of intercalation complexes are sensitive to moisture and must be handled in dry argon or nitrogen atmospheres. The alkali metal atoms occupy either octahedral or trigonal prismatic holes between X—M—X slabs. There are two principal means by which these compounds may be prepared. 

911-g quantity (0.008 mol) of 2f/(a)-TaS2 powder (or an appropriate mixture of the elements see Section A) is loaded into a quartz ampule such as the one described in Fig. la. The ampule is then transferred to a dry box with an argon or nitrogen atmosphere, and 74-129 mg (0.0032-0.0056 mol) of 

TABLE 1. Other Molecules that Intercalate TaSi 

Source From F. J. DiSalvo, Ph.D. dissertation, Stanford University 1971. 

In this method the metallic sodium is dissolved in a solvent such as liquid NH3 or tetrahydrofuran and the resulting solution is used to intercalate 2//(a)-TaS2. This technique was used by Cousseau and Trichet et al. in preparation of group IV layered transition-metal dichalcogenide-alkali-metal intercalation compounds. The advantage of this method is that it is carried out at room temperature and, consequently, there is less likelihood of reaction between sodium and the reaction vessel. On the other hand, this method is more difficult in that it involves the use of liquid NH3. Furthermore, undesirable side reactions may occur if the NH3 is not dried thoroughly or if the reaction vessel is not clean. For example, 

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