The Alkali Metal Salts of Methyl Xanthic Acid

Abstract

Methyl xanthates of the type M(SSC-OMe) (M = Li-Cs) are readily formed when carbon disulfide is reacted with the corresponding alkali metal hydroxides in methanol exposed to air, or with the alkali metal methoxides in dry methanol or THF under exclusion of air. The reactions are easily monitored by 13 C NMR spectroscopy. The Na, K, Rb, and Cs salt could be isolated in high yields, while the Li salt decomposed upon attempted isolation. All compounds are readily complexed by

Alkali Metal Dithiocarbamato Carboxylates (DTCCs) – Synthesis, Properties, and Crystal Structures

“…[4] The lower isolated yields using methanol as a solvent, as also discussed by Frank earlier, [16] are most likely due to the formation of the respective alkali metal methyl xanthate, M(SSC-OMe), as a by-product. [4,22] The efficient isolation of the solid products from their aqueous solutions is particularly demonstrated with 1-Na, which has been isolated as a liquid trihydrate 1-Na ⋅ 3H 2 O without acetone extraction by Frank, [16] and was now observed as a solid monohydrate 1-Na ⋅ H 2 O. On the other hand, a series of N-dithioato-l-prolinates (6) has been previously reported by Tlahuext et al and characterized as the anhydrous salts.…”

“…The coordination patterns of the dithiocarbamate group to the respective alkali metal ions observed for the reported compounds are characteristic and have been observed previously for other dithiocarbamates, [32][33][34][35] as well as for related dithiocarbonates. [22] As it is typical for the alkali metals which prefer usually ionic bonding in their compounds, both the MÀ S and the MÀ O distances cover wide ranges (see Table 3. For the sodium salts, the NaÀ O separations are in ranges of 232.83(8)-247.82( 8) pm (4-Na ⋅ 2H 2 O) and 232.4(2)-310.6(1) pm (6'-Na ⋅ 4H 2 O).…”