Aqua-(μ-cone-26,28-dibutoxy-25,27-bis-{N-[5-(dimethylamino) -naphthalene-1-sulfon-yl]carbamoylmethoxy}-5,11,17,23-tetra-kis-(1, 1-dimethylethyl)calix[4]arene(2-))disodium acetonitrile tetra-solvate

The structure of the title complex, [Na ₂(C ₈₀H ₉₈N ₄O ₁₀S ₂)(H ₂O)] ·4CH ₃CN, obtained after crystallization from aceto-nitrile, contains two formula units in the asymmetric unit (Z′ = 2) and an estimated four mol-ecules of acetonitrile per calixarene moiety. It is unusual for two Na ⁺ ions to occupy the lower rims of the cone calix[4]arene, as in this case, with one Na ⁺ ion forming two O Na ⁺ coordinate bonds with the two but-oxy groups and four such bonds with the two N-dansyl carboxamide groups, forming six dative bonds between Na ⁺ and O. On the other hand, the other Na ⁺ ion forms only five ONa ⁺ coordinate bonds on the far end of the calix[4]arene lower rim, bringing the two dansyl groups in close proximity with each other. There also appears to be an ONa ⁺ coordination coming from a dangling water mol-ecule. The structure contained both resolved and poorly resolved solvent mol-ecules. The latter were treated using the SQUEEZE routine in PLATON [Spek (2009). Acta Cryst. D65, 148-155].