Guest-Directed Supramolecular Architectures of {W36} Polyoxometalate Crowns

Autor: Thomas McGlone, Leroy Cronin, De-Liang Long, Carsten Streb
Rok vydání: 2009
Předmět:
Zdroj: Chemistry - An Asian Journal. 4:1612-1618
ISSN: 1861-471X
1861-4728
DOI: 10.1002/asia.200900242
Popis: The {W-36} isopolyoxotungstate cluster provides a stable inorganic molecular platform for the binding of inorganic and organic guest molecules. This is achieved by a binding pocket formed by six terminal oxo ligands located in the central cavity of the all-inorganic cation binding host. Previously it was shown that the cluster can specifically bind primary amines and importantly, functionalized diamines through a combination of electrostatic and hydrogen bonding interactions. Here we transform this assembly strategy to utilize the binding of long-chain alkyldiammonium guest cations to physical-ly define the supramolecular structure of the clusters with respect to each other and demonstrate the structure direction as a function of alkyl chain length. The systematic variation of the chain length gives access to five supramolecular assemblies which were all fully characterized using single crystal XRD, TGA, H-1 NMR, and elemental analysis. In compound 1, diprotonated 1,8-diaminooctane molecules link the {W-36} clusters into infinite 1D zigzag chains, whereas compounds 2 and 3 feature trimeric {W-36} assemblies directly connected through protonated 1,9-diaminononane (2) or 1,10-diaminodecane (3) linkers. Compound 4 contains dumb-bell shaped dimeric units as a result of direct center-tocenter linkages between the {W-36}) clusters formed by protonated 1,12-diaminododecane. In compound 5, triply protonated bis(hexamethylene)triamine was employed to obtain linear 1D chains of directly connected {W-36} cluster units .
Databáze: OpenAIRE
Externí odkaz: