Cyclic water hexamers and decamers in a porous lanthanide-organic framework: Correlation between some physical properties and crystal structure
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Michaelides, A.
(EN)
Πανεπιστήμιο Ιωαννίνων. Σχολή Θετικών Επιστημών. Τμήμα Χημείας
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Michaelides, A.
(EN)
Erbium. fumarate [Er-2(fum)(3)(H2O)(4)].8H(2)O, 1, (fum = fumarate dianion) crystallizes at room temperature in a silica gel column. The structure is three-dimensional and consists of layers of erbium fumarate pillared by fumarate dianions acting in the bis-chelating mode. The layers contain arrays of erbium cations bridged by fumarate dianions acting in the bis-bidentate bridging mode. The relatively large channels formed in the direction of the a and c axes are filled by water molecules that form a hydrogen bonded layer, comprising cyclic hexamers with both boat and chair conformations and cyclic decamers with boat-chair-boat conformation. The water molecules are reversibly removed at 90 degreesC. The evacuated metal-organic framework, 2, is stable up to 400 degreesC. Both compounds 1 and 2 exhibit weak antiferromagnetic interactions.
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