Role of Solvent-Host Interactions That Lead to Very Large Swelling of Hybrid Frameworks
C. Serre,1*
C. Mellot-Draznieks,1,2
S. Surblé,1
N. Audebrand,3
Y. Filinchuk,4
G. Férey1
An unusually large expansion upon solvent adsorption occurs without apparent bond breaking in the network of a series of isoreticular chromium(III) or iron(III) diarboxylates labeled MIL-88A to D [dicarbox = fumarate (88A); terephthalate (1,4-BDC) (88B); 2,6-naphthalenedicarboxylate (2,6-NDC) (88C); and 4-4'-biphenyldicarboxylate (4-4'-BPDC) (88D)]. This reversible "breathing" motion was analyzed in terms of cell dimensions (extent of breathing), movements within the framework (mechanism of transformation), and the interactions between the guests and the skeleton. In situ techniques show that these flexible solids are highly selective absorbents and that this selectivity is strongly dependent on the nature of the organic linker.
1 Institut Lavoisier, (UMR-CNRS 8180), Université de Versailles, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.
2 Royal Institution of Great Britain, 21 Albemarle Street, London W1S 4BS, UK.
3 Sciences Chimiques de Rennes (UMR-CNRS 6226), Université de Rennes 1, Avenue du Général Leclerc, 35042 Rennes Cedex, France.
4 Swiss Norwegian Beamlines (SNBL) at the European Synchrotron Radiation Facility (ESRF), rue Jules Horowitz, 38043 Grenoble, France.
* To whom correspondence should be addressed. E-mail: serre{at}chimie.uvsq.fr
