Two tetrachlorothiotantalates: [Na-15-crown-5] [TaSCl4 center dot dioxane]and [Na-15-crown-5](2)[(TaSCl4)(2)dioxane]center dot S-8

During the reaction of Na2S4, TaCl5 and 15-crown-5 in dichloromethane the c rown ether partly suffers degradation to 1,4-dioxane. Aside from sulfur, [N a-15-crown-5][TaSCl4 . dioxane] was the first product obtained. It crystall izes in the monoclinic space group P2(1)/n with a=1066.1, b = 1781.3, c = 1 258.3 pm, beta= 97.14 degrees, Z = 4. In the [TaSCl4 dioxane](-) ion a diox ane molecule is loosely bonded to a square-pyramidal TaSCl4- unit; two chlo rine atoms are in contact with an Na+ ion. Upon standing with the mother Li quor [Na-15-crown-5](2)[(TaSCl4)2dioxane]. S-8 was formed. It crystallizes in the monoclinic space group C2/m; a = 1768.5, b = 1084.0, c = 1517.3 pm, beta= 118.46 degrees, Z = 4. In this case a dioxane molecule is coordinated with two TaSCl4- units. The [(TaSCl4)(2) . dioxane](2-) ions and S-8 molec ules alternate in the stacking direction b.