Supramolecular cations of (m-halogenated-anilinium)(dibenzo[18]crown-6) in Keggin [SMo 12 O 40 2− ] polyoxometallates

Four supramolecular cations (m-XAni super(+))(DB[18]crown-6 ) (X = F, Cl, Br or I; Ani super(+) = anilinium ion; DB[18]crown-6 = dibenzo[18]crown-6) were introduced into crystals of a Keggin [SMo sub(12)O sub(40) super(2-)] polyanion to form [(m-XAni super(+))(DB[18]crown- 6)] sub(2)[SMo sub(12)O sub( 40) super(2-)].4CH sub(3)CN (1, 2, 3 or 4 for X = F, Cl, Br or I) through a hydrogen-bonding interaction. Crystals 1, 2, 3 and 4, which were isomorphous to each other, crystallized in the monoclinic space group P2 sub(1)/n. Supramolecular cations (m-XAni super(+))(DB[18]crown-6 ) were constructed by a N-H super(+)...O hydrogen-bonding interaction. [SMo sub(12)O sub(40) super(2-)] polyoxoanions were infinitely extended in three dimensions through a weak C-H...O hydrogen-bonding interaction with DB[18]crown-6. Disorder of the halogen atoms at the meta-position was observed in crystals 1, 2 and 3. The rotational freedom of the (m-XAni super(+)) cations was suppressed because of weak interactions with surrounding molecules.