Inclusion of two PhP(O)(OH)2 guest molecules into the cavity of the macrocyclic cavitand cucurbit[8]uril

A new inclusion compound which is a supramolecular adduct of cucurbit[ 8] uril with two guest molecules of phenylphosphonic acid, PhP(O)(OH)(2), included into the cavity as "two guests in host" is reported. The guests match both size and hydrophilicity/hydrophobicity requirements. Two phenyl groups of molecules of PhP(O)(OH)(2) are directed toward the center of the large hydrophobic cavity whereas the PO(OH)(2) groups are outward-looking and bound with each hydrophilic portal of cucurbit[ 8] uril by a short hydrogen bond.