Effects of Cocrystalline Subunits on the Supramolecular Chemistry of Me10Q[5]: From Simple Inorganic Anions to Cluster Anions

Five supramolecular assemblies, formulated as {K2(H2O)3·[(Me10Q[5])@(H2O)0.5]}·Cl2 1, [K2(H2O)2·(Me10Q[5]@H2O)](ClO4)2·H2O 2, {K(H2O)·K(H2O)(SCN)Me10Q[5]}·(SCN)·H2O 3, [Na2(H2O)2K2(H2O)4(Me10Q[5])]·[Mo8O26] 4 and [Na2(H2O)2Rb2(H2O)4(Me10Q[5])]·[Mo8O26] 5, have been successfully isolated. Compounds 1−5 exhibit various structures based on the coordination of Me10Q[5] with alkali metals controlled by a series of anions, in which the anions play multiple roles of coordination, space-filling, charge-compensating etc. In the structure of compound 1, Me10Q[5] is capped by two [K(H2O)2]+ moieties through the carbonyl O atoms on the portals to form a bicapped unit. The bicapped Me10Q[5] units are interconnected to form a covalent bonded chain structure. Uncoordinated Cl− anions fill in the crystal lattice behaving as both counterions and space-filling agents. Compound 2 possesses isolated bicapped units comprised by Me10Q[5] and [K(H2O)]+ moieties, which are further linked via extensive hydrogen bonding interactions between the coordinated and uncoordinated water molecules into a supramolecular chain structure. The ClO4− anions are involved in the formation of hydrogen bonds with the coordinated aqua ligands located on the supramolecular chains. Compound 3 features an asymmetric bicapped Me10Q[5] unit due to the coordination of a [K(H2O)]+ or [K(H2O)(SCN)]+ on each portal of Me10Q[5]. The bicapped units in 3 are further extended into a supramolecular chain structure by hydrogen bonds between the coordinated water and carbonyl O atoms of Me10Q[5]. Moreover, uncoordinated SCN− anions are also observed in the crystal lattice. Compounds 4 and 5 are isomorphous and display interesting 3D network structures built by the interconnections of Me10Q[5], mixed alkali metal cations (Na+/K+ for 4 and Na+/Rb+ for 5), and [α-Mo8O26]4− cluster anions. In this study, the supramolecular assemblies of Me10Q[5] based solids show an anion dependent feature, which is systematically explored.