25,27:26,28‐Bis(3,9‐dioxa‐6‐aza­undecane‐1,11‐dioxy)­calix­[4]­arene tetrahydrate

The title compound, C₄₄H₅₄N₂O₈·4H₂O, has twofold crystallographic symmetry and consists of a calix­[4]­arene moiety with four phenyl rings arranged alternately in anti‐orientation fashion and two aza­crown units attached on the lower rims of calix­[4]­arene. This seems to offer a big cavity inside the mol­ecule which might possess a potential for forming host–guest complexes.