Manipulation of molecular aggregation and supramolecular structure using self-assembled lithium mixe
June 28th, 2008 | by admin |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-Me(3)-C(6)H(2)OLi (ArOLi) and Me(2)N(CH(2))(2)OLi (ROLi) within single aggregates, while using 1,4-dioxane (diox) as a ditopic linker. The homoleptic complex [{(ArOLi)(4).(diox)(2)} superset3(diox)](infinity) forms a 3D diamondoid extended structure, where Li(4)O(4) 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).(diox)(1.5)} superset1/2(C(6)H(14))](infinity) and [(ROLi)(4)(ArOLi)(2).(diox)](infinity), adopt 2D hexagonal net and 1D chain structures respectively. Furthermore, the two complexes [{(ROLi)(3)(ArOLi)(3).(diox)(0.5)}(C(6)H(14))](infinity) and [(ROLi)(5)(ArOLi).(diox)(0.5)](infinity) 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 Li(4)O(4) units to hexametallic Li(6)O(6) units.
Morris JJ, Macdougall DJ, Noll BC, Henderson KW.
Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, 46556, IN, USA. khenders@nd.edu.