Two Tetrachlorothiotantalates: [Na-15-crown-5][TaSCl_4 centre dot dioxane] and [Na-15-crown-5]_2[(TaSCl_4)_2dioxane] centre dot S8

摘要

During the reaction of Na_2S_4, TaCl_5 and 15-crown-5 in dichloromethane the crown ether partly suffers degradation to 1,4-dioxane. Aside from sulfur, [Na-15-crown-5][TaSCl_4 centre dot dioxane] was the first product obtained. It crystallizes in the monoclinic space group P2_1 with a = 1066.1, b = 1781.3, c = 1258.3 pm, #beta# = 97.14 deg, Z = 4. In the [TaSCl_4 centre dot dioxane]~- ion a dioxane molecule is loosely bonded to a square-pyramidal TaSCl_4~- unit; two chlorine atoms are in contact with an Na~+ ion. Upon standing with the mother liquor [Na-15-crown-5]_2[(TaSCl_4)_2dioxane] centre dot S8 was formed. It crystallizes in the monoclinic space group C2/m; a = 1768.5, b = 1084.0, c = 1517.3 pm, #beta# = 118.46 deg, Z = 4. In this case a dioxane molecule is coordinated with two TaSCl_4~_ units. The [(TaSCl_4_2) centre dot dioxane]~(2-) ions and S_8 molecules alternate in the stacking direction b.