Alkali-metalated forms of thiacalix[4]arenes

The alkali metal salts [TCALi(4)] (1), [TCANa(4)] (2), and [TCALK(4)] (3) of fully deprotonated p-tert-butyltetrathiacalix-[4] arene (H(4)TCA) are readily available from the reactions of thiacalix[4] arene and n-BuLi, NaH, or KH as deprotonating reagents. Crystals of the sodium salts 2 and the potassium salt 3 suitable for X-ray diffraction were obtained in the form of the pyridine solvates [(TCA)(2)Na-8 center dot 8py] (2 center dot 8py) and [(TCA)(2)K-8 center dot 8py] (3 center dot 8py). These molecules are dimers in the solid state but are structurally not related. In addition, the reaction of H4TCA and lithium hydroxide afforded the structurally characterized complex [(TCA) Li-5(OH)center dot 4THF] (4). The molecular structure of 4 as well as the structures of 2, 8py and 3, 8py reveal a close relationship to the corresponding alkali metal salts of the calix[4] arenes.