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Transition-Metal Porous Coordination Polymers with a Podand Ligand: Structure of Discrete Water Clusters and Variable-Temperature Magnetism

✍ Scribed by Subhadip Neogi; E. Carolina Sañudo; Parimal K. Bharadwaj


Publisher
John Wiley and Sons
Year
2007
Tongue
English
Weight
470 KB
Volume
2007
Category
Article
ISSN
1434-1948

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✦ Synopsis


Abstract

The podand ligand tris(4‐carboxy‐2‐phenoxyethyl)amine (ptaH~3~) readily reacts with Co^II^, Mn^II^ and Ni^II^ salts at room temperature to afford porous coordination polymers, {Co(ptaH)·5H~2~O}~n~ (1), {[Mn(ptaH)(H~2~O)]·4H~2~O}~n~ (2), and {[Ni(ptaH)(4H~2~O)]·6H~2~O}~n~, (3). Crystallographic studies performed on these systems reveal that their structures are based on infinite chains of interlinked metallacycles. The bridging carboxylate groups extend the open framework structures, with oval‐shaped voids. Supramolecularly assembled water clusters of different sizes, whose structures are proportionate with the size and shape of the MOFs, fill these voids. While discrete (H~2~O)~10~ clusters are present in 1 and 2, both (H~2~O)~2~ and (H~2~O)~16~ clusters occupy the voids in 3. Magnetic susceptibility measurements, in the temperature range 2–300 K, on 1 and 2 reveal that the metal centers are antiferromagnetically coupled in each case. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)