J. Jacob Morris

High-connectivity networks: characterization of the first uninodal 9-connected net and two topologically novel 7-connected nets

Ring and cage aggregates containing the large alkali metals potassium or rubidium have proven to be excellent building blocks for the creation of high-connectivity nets, as demonstrated by their use as septahedral and nonahedral nodes in synthesis of two new types of 7-connected nets and the first ever example of a 9-connected net.

High-Connectivity Networks and Hybrid Inorganic Rod Materials Built from Potassium and Rubidium p-Halide-Substituted Aryloxides

A series of complex networks have been synthesized from the association of potassium and rubidium p-halide-substituted aryloxides using 1,4-dioxane molecules as neutral linkers. The crystalline polymers [(4-F-C6H4OK)6 x (dioxane)4]infinity (1), [(4-I-C6H4OK)6 x (dioxane)6]infinity (2), and [(4-I-C6H4ORb)6 x (dioxane)6]infinity (3) are built from discreet, hexameric M6O6 aggregates. Compound 1 forms an unusual 16-connected framework involving both K-F and K-O(diox) interactions. Each hexamer connects to eight neighboring aggregates through double-bridging contacts, resulting in a body-centered cubic (bcu) topology. Compounds 2 and 3 are isostructural, 12-connected networks, where each aggregate utilizes six dioxane double bridges to form primitive cubic (pcu) nets. In contrast, the complexes [(4-Cl-C6H4OK)3 x (dioxane)]infinity (4), [(4-Br-C6H4OK)2 x (dioxane)0.5]infinity (5), and [(4-Br-C6H4ORb)5 x (dioxane)5]infinity (6) are built from one-dimensional (1D) inorganic rods composed solely of M-O(Ar) interactions. The extended structures of both 4 and 5 can be described as pcu nets, where parallel 1D inorganic pillars are connected through dioxane bridges. Compound 6 is also composed of parallel 1D inorganic rods, but in this instance the coordinated dioxane molecules do not bridge, resulting in isolated, close-packed chains in the solid state.

Manipulation of molecular aggregation and supramolecular structure using self-assembled lithium mixed-anion complexes

A set of zero-, one-, two-, and three-dimensional materials have been synthesized by systematically varying the stoichiometry of the two components 2,4,6-Me3-C6H2OLi (ArOLi) and Me2N(CH2)(2)OLi (ROLi) within single aggregates, while using 1,4-dioxane (diox) as a ditopic linker. The homoleptic complex [{(ArOLi)4 x (diox)2} superset3(diox)](infinity) 1 forms a 3D diamondoid extended structure, where Li4O4 cubanes act as tetrahedral nodes. Attempts to rationally alter the dimensionality of the network through the sequential replacement of ArOLi vertices by potentially chelating ROLi units have succeeded. The mixed-anion complexes [{(ROLi)(ArOLi)3 x (diox)(1.5)} superset1/2(C6H14)](infinity) 2 and [(ROLi)4(ArOLi)2 x (diox)](infinity) 4 , adopt 2D hexagonal net and 1D chain structures respectively. Furthermore, the two complexes [{(ROLi)3(ArOLi)3 x (diox)(0.5)}(C6H14)](infinity) 3 and [(ROLi) 5(ArOLi) x (diox)(0.5)](infinity) 5 both form unusual 0D molecular dumbbell structures in the solid state. Incorporation of multiple ROLi units in the mixed-anion complexes not only results in reducing the number of possible sites for polymer extension through chelation, but also changes the aggregation state of the building block from tetrametallic Li4O4 units to hexametallic Li6O6 units.

Use of tetrameric cubane aggregates of lithium aryloxides as secondary building units in controlling network assembly

Pre-aggregation of lithium aryloxides into tetrahedral arrangements followed by crystallization with the divergent Lewis base dioxane results in the preparation of three types of coordination polymers: zig-zag chains, (6,3) sheets, and diamondoid lattices.