Zinc and Cobalt Aqua Complexes with Cucurbit[6]uril: Syntheses and Crystal Structures

Resumo

Supramolecular complexes [Zn(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ · 6.5H₂O (I), [Zn(H₂O)₄-(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ · 7H₂O (II), and [Co(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ · 7H₂O (III) are synthesized by the slow (for I and III) and fast (for II) cooling (after reflux) of aqueous solutions of a mixture of salts of the corresponding metals and cucurbit[6]uril. According to the X-ray diffraction data (СIF files CCDC nos. 1862494 (I), 1862495 (II), and 1862496 (III)), the supramolecular complexes are the first examples of the direct coordination of the zinc and cobalt atoms to the cucurbit[6]uril molecule. Compounds I–III are characterized by X-ray diffraction analysis, thermogravimetry, IR spectroscopy, and elemental analysis.